New BT build, mystery misfires at idle and part throttle

[QuattroBucc]

I just finished up my BT build and fixed some wiring issues I was having and now upon startup I get random misfires while idling, I looked at the misfire counter on vagcom for cylinders 1-4 and it randomly misfires mostly in cylinder 4 and half the time in 2 like every 10 seconds or so, Fuel trim is moving around a ton jumps up and down up to +-15% ,

its not popping any CEL codes at all other than evap incorrect flow because I deleted evap/capped off all the lines. But I'm not getting any misfire codes, I tried taking it down the road and it misfires and cuts throttle a ton at part throttle when just trying to maintain speed, if im slightly accelerating past 25% throttle it seems to clear up and drive fine but I turned straight around and drove past part throttle the whole way so it wouldn't misfire.

I'm stumped-I think its a vacuum leak or bad main o2 sensor, at idle i only have -11 to -12 of vacuum but my car does have 252/260 cams so I'm not sure what normal vacuum is supposed to be for a cammed BT car. I've replaced every single vacuum line with new line and clamps, new sparkplugs with the new build. besides the random misfires happening every 10 sec it idles super smooth but does seem a bit high at 1000rpm which leads me to believe its a vacuum leak,

I can't locate any hissing really because the between the clutch fan right and my exhaust there its loud in the engine bay. The only culprit of a vacuum leak that I could think is possible is the intake manifold gasket/throttlebody gasket/BOV V band- because I used a phenolic spacer for the intake manifold with a gasket on each side of it, but I already took that off and applied RTV on both sides of each gasket and put it back on and the engine has the same vacuum so I don't think its that. throttlebody gasket i re-used but applied some thin RTV on it, and then I have a 50mm Tial recirculating but it is V-band clamped and I think I can hear a tiny amount of hissing right at the clamp spot but the V-band is fully tight. If the vacuum leak is there I'm not sure how to make it a better seal since it is already V-band.

My next step of plan is to have a mobile mechanic come out and smoke test the vacuum system. If anyone else has any ideas of what the mystery misfire is from please do tell!

Sorry its a lot to read but I figured I'd just get all the info I have so far Out there!

[Blazius]

1. Evap needs a tune for complete removal.
2. You need to seal the recirculation completely, if its a vacuumed system it will be open on idle and part throttle to improve response.

If fuel trims are changing that much and you know the car has been tuned properly injectors dialed in then yes it does point to a leak, what about ltfts?

[QuattroBucc]

I don't mind the evap code, but does it affect how the car runs without it tuned out- even when you cap off all the vacuum lines coming into the engine bay?

The tune is dialed for the injectors- it runs good and smooth besides the random misfire.

I just ran the 032 block on vagcom and got 1st value 10.9% and 2nd value -.8%. At idle if i monitor my AFR guage I can tell its trying to stay around 14.7afr but it goes down and up into low 14s and low 15s I think from a vacuum leak. If i slowly give it gas it revs up just fine but if I punch the gas instantly to 25% throttle position it hesitates for half a sec and misfires then revs up. When I took my cruise the other day at part throttle trying to maintain speed afr would jump up to 16-17 then off the chart-guage wont read it anymore its so lean, past part throttle afrs are steady and it doesnt misfire, but I'm not taking it out driving it again until I have this figured out and not misfiring at idle at all

[Akabetterthanu]

Could it be timing? Either crank to cam or int cam to exh cam?


Sent from my iPhone using Audizine Forum

[Blazius]

I don't mind the evap code, but does it affect how the car runs without it tuned out- even when you cap off all the vacuum lines coming into the engine bay?

The tune is dialed for the injectors- it runs good and smooth besides the random misfire.

I just ran the 032 block on vagcom and got 1st value 10.9% and 2nd value -.8%. At idle if i monitor my AFR guage I can tell its trying to stay around 14.7afr but it goes down and up into low 14s and low 15s I think from a vacuum leak. If i slowly give it gas it revs up just fine but if I punch the gas instantly to 25% throttle position it hesitates for half a sec and misfires then revs up. When I took my cruise the other day at part throttle trying to maintain speed afr would jump up to 16-17 then off the chart-guage wont read it anymore its so lean, past part throttle afrs are steady and it doesnt misfire, but I'm not taking it out driving it again until I have this figured out and not misfiring at idle at all

Yes first value is idle trim, 10% is quite a lot. Its adding 10% fuel , so it means you have unmeasured air entering the engine post maf. Smoke test if you can , check for leaks.

[B5carl]

MAP sensor? I'm guessing if vaccum was lower than 9-10inHg then it would be a problem but sounds like it could be a sensor issue.

If the exhaust manifold has a crack in it that would cause a lot of popping and backfiring

And make sure throttle body venturi is clean.

[QuattroBucc]

its AEB car there is no MAP sensor. its not popping/backfiring its misfiring due to AFR moving around due to vacuum leak im sure of, waiting on a pressurized smoke test

throttle body is brand new so 0 carbon on it.

[B5carl]

My 1.8t also misfires at idle sometimes too BUT that's because I broke all the tabs on the coil pack harness connector so make sure all the wiring from the harness isn't burnt and clean the coil pack connections. Mine are barely holding on because of the connectors being loose. Make sure you actually tightened down the spark plugs...

Your upstream o2 sensor should either be new or in almost perfect condition also. That could also cause the ecu to read unstable values if it's old or faulty.

Check all the grounds too. Battery ground and the one on the valve cover. Clean with wire brush and brake cleaner.

[QuattroBucc]

lol spark plugs are gapped to .028 and tightened to 21 ft/lbs that'd be impossible to forget to tighten them. coil packs and harness seem to be fine and new sparkplugs, wiggling the coil harness around doesnt change anything either like it would if it was loose. O2 sensor is pretty new (4 months) but how would I go about checking it?, every ground is solid, the ones by the starter, battery, valve cover, alternator. its all solid and tight

[B5carl]

lol spark plugs are gapped to .028 and tightened to 21 ft/lbs that'd be impossible to forget to tighten them. coil packs and harness seem to be fine and new sparkplugs, wiggling the coil harness around doesnt change anything either like it would if it was loose. O2 sensor is pretty new (4 months) but how would I go about checking it?, every ground is solid, the ones by the starter, battery, valve cover, alternator. its all solid and tightJust asking because if your putting a motor together it's easy to forget something like that.

I'm guessing you have an upgraded fuel pump and filter so it's probably not fuel related. Do you have a fuel pressure gauge hooked up? It could even be your crank position sensor because that essentially measures misfires. Idk I'm just throwing ideas. CPS would also cause slow starting issues.

If your o2 sensors are new, connections are clean and secure then I doubt they're faulty but if you have access to a high end shop OBD2 scanner some of them can graph real time voltage readings using x as real time and y as voltage so you can see if the sensor voltage acts unstable at idle.

Another guy mentioned cam timing. You said that it drives fine past 25% throttle that actually sounds like an advancement issue especially on the AEB since there's no VVT. Maybe your timing is off a bit

[QuattroBucc]

Yes to upgraded fuel pump and filter, no fpr hooked up just the stock 3 bar in there the tune calls for, it starts up like 1st crank so i'm not having slow start issues. o2 sensors are new but were also in the old motor which had a HG leak putting tiny amounts of coolant burning into the exhaust so maybe that killed them, but old motor still ran completely fine and didnt have a vacuum leak or anything like this. I think i can look at realtime o2 sensor voltage on VAGCOM so ill check that out, the cams relation as far as I know is timed correctly , i went based on what SPA said since there was no timing marks on the gears they said have the faces of the gears with writing completely straight matching eachother, then counted the links inbetween like stock would. Crank to cams timing is probably 1* advanced because using the manual timing belt tensioner kit it was damn near impossible to get the timing marks to line up exactly 100% when i went to tighten the tensioner, closest i could get it was with crank gear right at the mark and cam mark up top like 1mm past the mark, I did some googling and didn't find that this would be bad for the motor at all because people advance or retard their cam centerlines way more than 1 degree, and some people add in vvt which advances up to 25* iirc. Would 1 or 2 degree of cam advance in relation to crank cause misfires like this? I feel like its a vacuum leak because vacuum is low and lamba is bouncing around, would lambda bounce around wrong cam timing? I wouldn't think so- just misfire

[B5carl]

I actually talked to one of the guys at integrated engineering the other day because I bought the adjustable cam gear and told them that the mark on the gear was out of line and he said to mark it out with a black marker and follow the machined mark. After that he told me that even if it was off 1/2 a degree or whatever it wouldn't matter because VVT would kick in a adjust it.

SPA cams aren't adjustable so you don't have to worry about centerline tuning stuff and it wouldn't cause any of the symptoms your describing anyways.

Im guessing you did everything correctly. I would check compression in all the cylinders at this point just in case maybe the valves are not seated and causing leaks, low compression and misfires.

Did you try resetting the ecu? The trim is probably all messed up if all it's remembering is misfires and trying to recalibrate. If it has barely any mileage on it then it's gonna have terrible mpg until it either gets reset or adds more memory with the car running as it should.

[QuattroBucc]

these spa cams actually did come only with adjustable cam sprockets but I just tightened down all the nuts with it in the middle, not advanced or retarded. but now that you guys mentioned timing I'm thinking about the timing between intake and exhaust cam, but I feel like if that was messed up it wouldn't idle smooth at all, or even run, and the misfires would be constant every firing cycle then right? not just intermittently every 10-15 secs idling. On monday I'm getting a smoke test to hopefully find a vacuum leak which I think all this trouble is coming from. If Theres no leaks then I really have no idea besides trying to replace the o2 sensor and coilpacks.

[QuattroBucc]

and yes when I reset the ecu it doesn't make thaaat much of a difference, soon as i start back lamda starts bouncing around and trying to fix itself lol it basically goes from 14.0 up to 15.5 and bouncing around between those areas adding fuel because its getting extra air from somewhere (i think) then it goes to 14 and pulls a lil bit of fuel out because its trying to maintain 14.7, so it just goes up and down between those two but it doesnt go pig rich or super lean

[B5carl]

So if you got the adjustable cams then you have to degree them correctly using a dial gauge, degree wheel etc. You basically want it to match the exhaust so there would be 0 degrees of difference between both as a start.

I don't know exactly how to do it you can find a DIY online on how to do it but they only tell you how to match them, which is all you need because who knows if it's that far off then it could be causing a huge leak on the compression stroke causing low compression and misfiring.

The first thing I would do is compression test THEN degree them properly THEN do another compression test.

I wouldn't trust it from the factory especially if they didn't specify if they degrees them or not. An then check the timing marks again on both cams.

At this point It doesn't seem like a vaccum leak. If the cams aren't even degreed correctly then that could definitely cause low compression issues.

[B5carl]

You also had another thread on hooking up a ProMAF. I wouldn't hook it up unless tuned in. It needs both + and - signals to do the 360 sampling and the tuner has to tune in the math so it can do the averaging etc... Just stick with the stock MAF and clean it.

[QuattroBucc]

The promaf is what my tuner called for specifically, its wired in correctly now.

What do you mean exactly? They have the adjustable sprocket on the cams but I tightened them down both at 0*, I'm not trying to use the adjustability. Wouldn't I only need to degree them if I was actually adjusting the centerlines?

[B5carl]

The promaf is what my tuner called for specifically, its wired in correctly now.

What do you mean exactly? They have the adjustable sprocket on the cams but I tightened them down both at 0*, I'm not trying to use the adjustability. Wouldn't I only need to degree them if I was actually adjusting the centerlines?Aright so the ProMAF shouldn't be an issue.

From what I know if you get cams with adjustable gears then they need to be degreed during installation unless otherwise specified by the manufacturer. If they didn't mention anything about it you should either email them and ask if they are already degreed or assume that they are not.

Especially if you had to re-tighten them... You should also use loctite on those bolts... should have gotten the IE cams they are drop in ready to go, no adjustablity just a solid gear that virtually will never fail. I don't trust those gears they break all the time from what I've heard.

[QuattroBucc]

Yeah I emailed Spa about how to even set them in because they have no timing marks on the gear all they said was to reference to their picture where the writing is flat on the gears and put them in like that, they said nothing about having to degree them during installation. But still not having a timing mark at all and just trying to put them in "flat" they are probably off a hair in relation to eachother. I had to re-tighten because the bolts broke while torqueing the gear on. put in 10.9 hardness ones then. Yeah I would of gone with IE cams If I didn't already have the SPA laying around. now I'm thinking I should just ditch the SPA and sell them and just drop in the I.E. one lol because yea I am worried about the flimsy adjustable sprocket letting go-I've read numerous horror stories

[B5carl]

I almost bought those cams too lol I emailed them about the timing marks and they never responded. Then I found out IE starting manufacturing the IECVA series again so I got theirs.

Anyways I'd check compression to see where your at. If those cylinders are low then there's your leak.

[QuattroBucc]

I bit the bullet and bought the I.E.'s just now just for the reassurance of reliability I don't want my spa gears to come apart in my fully built head, not too bad of a job dropping in the cams and then Ill be sure they're timed properly. Still gonna do that compression check tomorrow to see where things are at.

[B5carl]

I bit the bullet and bought the I.E.'s just now just for the reassurance of reliability I don't want my spa gears to come apart in my fully built head, not too bad of a job dropping in the cams and then Ill be sure they're timed properly. Still gonna do that compression check tomorrow to see where things are at.Nice

[Blazius]

I told you. That kind of fuel trim is leak or simply wrong setup on the ecu, such as bad opening delay of injector, bad scaling of the promaf which would rather show up in the 2nd box as its a multiplicative trim.


Did you sort the recirc yet? If not do that.

[QuattroBucc]

ecu should be correct tho its a united motorsports stage 4 tune on the ecu with their promaf and 630cc injectors it all calls for. yes I got the DV recirc all sealed up but that did not change a single thing.

[QuattroBucc]

just did a compression test, tester said to warm up the engine first then test with all plugs out and throttle at WOT. Not very good results it seems, cyl 1-3 are all at 130psi then 4 at 110, cyl 4 is the one misfiring the most but these numbers don't seem insanely low to make sense of the misfire, what do you think?

[B5carl]

just did a compression test, tester said to warm up the engine first then test with all plugs out and throttle at WOT. Not very good results it seems, cyl 1-3 are all at 130psi then 4 at 110, cyl 4 is the one misfiring the most but these numbers don't seem insanely low to make sense of the misfire, what do you think?It could be because the cams where not degreed properly and maybe a tooth off on timing from the gear to the crankshaft. Not having VVT could be causing the issue maybe?? The valves could be opening to soon.

[QuattroBucc]

It could be because the cams where not degreed properly and maybe a tooth off on timing from the gear to the crankshaft. Not having VVT could be causing the issue maybe?? The valves could be opening to soon.

I'm hoping its just the cam timing, could also be bad valve sealing but I lapped all new valves and did the water test and nothing leaked past. Idk but this is becoming a pain in my ass lol, it was hard enough doing all the work and installing the engine, i just want it to run right so i can break it in and enjoy the build.

[B5carl]

I'm hoping its just the cam timing, could also be bad valve sealing but I lapped all new valves and did the water test and nothing leaked past. Idk but this is becoming a pain in my ass lol, it was hard enough doing all the work and installing the engine, i just want it to run right so i can break it in and enjoy the build.Sounds like it's almost done. Hopefully it is just the cam adjustment issue. It makes since too if all the cylinders are low

[QuattroBucc]

Sounds like it's almost done. Hopefully it is just the cam adjustment issue. It makes since too if all the cylinders are low

Yea hopefully it gets sorted with the new Cams that actually have timing marks Ha, Thanks for the help!

[Blazius]

Mistimed cam will absolutely idle like shit that is true. Just because the ecu is right does not mean the calibration is correct but it should lets say it is. What does group 93 say in VCDS? Did you wet test? Also if you can talk to your tuner to raise idle with big cams they like to misfire on lower rpms. Also do you by any chance have TFSI coils [:D]

[QuattroBucc]

Mistimed cam will absolutely idle like shit that is true. Just because the ecu is right does not mean the calibration is correct but it should lets say it is. What does group 93 say in VCDS? Did you wet test? Also if you can talk to your tuner to raise idle with big cams they like to misfire on lower rpms. Also do you by any chance have TFSI coils [:D]

ill email the tuner, maf readings at idle were a steady 6g/s when it was wired in correctly now it bounces from 5g to 8gs so maybe the promaf got fried. Is there a way to test it? like voltage ?? group 93 says N/A. I didn't wet test when i did the compression test just fully warmed up. and Yes I have an ICM delete/conversion harness with the "r8" plugs, are you not a fan of them? do you rock Oem 3 prong plug style? what do you recommend

[Blazius]

Its bouncing cause probably your RPM is bouncing around no?

ICM delete is okay but the thing is with any coil conversion proper tuning and changing should be done because the coil charge times etc are different. You being on the older ecu I cant exactly give you straight answers but if your tuner is any competent he should be able to find the maps and correct them , else you might kill some later on.
With what I know I would recommend 115E coils(hitachi) on these motors, they were never superseeded and afaik they have the biggest coil winding. They also bolt onto your valve cover properly and waterproof seal it. These are the coils from Audi RS6 btw.

p/n - 06B-905-115E

Overall I dont think your issue is being caused the coils unless some are dying.

[QuattroBucc]

Its bouncing cause probably your RPM is bouncing around no?

ICM delete is okay but the thing is with any coil conversion proper tuning and changing should be done because the coil charge times etc are different. You being on the older ecu I cant exactly give you straight answers but if your tuner is any competent he should be able to find the maps and correct them , else you might kill some later on.
With what I know I would recommend 115E coils(hitachi) on these motors, they were never superseeded and afaik they have the biggest coil winding. They also bolt onto your valve cover properly and waterproof seal it. These are the coils from Audi RS6 btw.

p/n - 06B-905-115E

Overall I dont think your issue is being caused the coils unless some are dying.

RPM is not bouncing around, it stays a steady 900-1000 rpm depending on which one rpm it chooses to go with lol. Yea i have heard you have to tune in the different dwell times for the TFSI coils, but I did read that the R8 coils which i think are same as tfsi? all the red tops i think are the same, put out more resistance than the rs6 ones "R8 V10 are the best and do have a slight higher resistance rating which means a slightly better spark 5.2 Mohms compared to RS4 3.8 Mohms from memory." from https://forum.rs246.com/viewtopic.php?t=126151
"The higher resistance makes a better spark because (as I understand it) its related to the secondary winding around the coilpack that allows a greater strength field to be available when the primary is collapsed which is what gives a hotter, brighter spark - allowing you to open the gaps on the plugs all other things being equal or keep the gaps the same in a harsher environment in, for example, a higher compression or more densely charged cylinder."

and "What i can definitely say from personal experience is that they make a distinct improvement at 400bhp, 500bhp, 600bhp and beyond in turbocharged 4 & 6 cylinder engines and will be used in my 900bhp engine this year !!"

what do you think about that? If the r8 v10 coilpacks literally put out 1.4 more Mohms of resistance equating to more spark couldn't you run a larger cap under higher boost than you could with rs6 ones? with the proper tuning for dwell times etc of course

[Blazius]

Coil resistance is not the only thing that you have to take in account. It pretty much only useful if you are comparing the same coils and want to find out if one is "worse" or failed than the other. The main other factors are physical size, number of turns of windings, turn ration , core , core material, eventually the inductance.
The dwell time for the tfsi/r8/etc. is 2.0-2.5ms, the older bigger coils are much higher. Why is this you might ask, well like I said different construction from many factors but its not necessarily a bad thing. The bigger your heatsink btw aswell the more charge time you can run, which means more current in primary winding which produces a stronger spark when it collapses.

If you want to be scientific you could buy a rs6 115e coil and cut it open vs a tfsi coil, and check which one has bigger windings, heatsinks [:d] that will give an answer for sure.

But either way these coils are nowhere near as good LS coils, they blow these out from the water if you ever wanna get serious about coilpacks on a high power build.

[QuattroBucc]

Coil resistance is not the only thing that you have to take in account. It pretty much only useful if you are comparing the same coils and want to find out if one is "worse" or failed than the other. The main other factors are physical size, number of turns of windings, turn ration , core , core material, eventually the inductance.
The dwell time for the tfsi/r8/etc. is 2.0-2.5ms, the older bigger coils are much higher. Why is this you might ask, well like I said different construction from many factors but its not necessarily a bad thing. The bigger your heatsink btw aswell the more charge time you can run, which means more current in primary winding which produces a stronger spark when it collapses.

If you want to be scientific you could buy a rs6 115e coil and cut it open vs a tfsi coil, and check which one has bigger windings, heatsinks [:d] that will give an answer for sure.

But either way these coils are nowhere near as good LS coils, they blow these out from the water if you ever wanna get serious about coilpacks on a high power build.

Alright I am so frustrated/tired of working on this thing I should have just had a machine shop fully assemble it because I fucked up somewhere. I just dropped in the I.E. cams that have timing marks so I could be sure timing was 100% and This time I try to start it up its even worse than before, even after clearing all codes and resetting throttle body alignment it has less vacuum than before, cant idle smooth for anything and misfire counter is going up so fast its almost like every single combustion cycle is a misfire, Everything else is the same, I tried swapping coilpacks and sparkplugs but it didn't change anything. Tested compression before startup and it was 130 across the board which sucks by itself- Here is the pics of my timing so I'm not sure what has gone wrong https://imgur.com/a/fGGFrbD. At this point I feel like I should just pull the motor and drop it off at a machine shop because I am completely lost

[B5carl]

Alright I am so frustrated/tired of working on this thing I should have just had a machine shop fully assemble it because I fucked up somewhere. I just dropped in the I.E. cams that have timing marks so I could be sure timing was 100% and This time I try to start it up its even worse than before, even after clearing all codes and resetting throttle body alignment it has less vacuum than before, cant idle smooth for anything and misfire counter is going up so fast its almost like every single combustion cycle is a misfire, Everything else is the same, I tried swapping coilpacks and sparkplugs but it didn't change anything. Tested compression before startup and it was 130 across the board which sucks by itself- Here is the pics of my timing so I'm not sure what has gone wrong https://imgur.com/a/fGGFrbD. At this point I feel like I should just pull the motor and drop it off at a machine shop because I am completely lostWhat about the crank position sensor???? PCV???Check compression after you installed the new cams? The CPS is important in determining ignition firing times. You could have bent valves maybe from not installing the SPA cams correctly? The motor and sensor system really isnt that complex to understand.

If you smoke tested it and found nothing then maybe you hooked up the vacuum system wrong if you tried to simply it. I wouldn't delete anything unless you understand how it works. Like if you deleted the SAI/combi valve then it needs to get tuned out. I wouldn't delete evap because that could be hazardous if you have pressurized fume in your tank etc. Idk if deleting evap will make a difference on just getting it to idle. I also wouldn't delete the suction jet pump because it could drop vaccum pressure by alot if not hooked up correctly

At least the new cams will be more reliable than the SPA so you did waste money on them.

[B5carl]

If your crank position sensor is bad your fuel pump wont work right either

PCV could be bad too if it's not OEM. I know 034 made a billet PCV and the first version wasn't good alot of people said the car idled differently so they made a new version. Either way if the spring rate for it effects idling that much then I would stick with OEM.

Compression wise Im not sure. I think anything over 100 shouldnt cause misfiring but you should check again go make sure. I had a B6 1.8t a few years ago and it had a blown head gasket but it idled not to bad for a blown head gasket.

Cam position sensor could cause the same problem too...

Try unplugging the ProMAF see if that does anything

[QuattroBucc]

What about the crank position sensor???? PCV???Check compression after you installed the new cams? The CPS is important in determining ignition firing times. You could have bent valves maybe from not installing the SPA cams correctly? The motor and sensor system really isnt that complex to understand.

If you smoke tested it and found nothing then maybe you hooked up the vacuum system wrong if you tried to simply it. I wouldn't delete anything unless you understand how it works. Like if you deleted the SAI/combi valve then it needs to get tuned out. I wouldn't delete evap because that could be hazardous if you have pressurized fume in your tank etc. Idk if deleting evap will make a difference on just getting it to idle. I also wouldn't delete the suction jet pump because it could drop vaccum pressure by alot if not hooked up correctly

At least the new cams will be more reliable than the SPA so you did waste money on them.
Crank position sensor and cam position sensor was a brand new unit, guess i could try putting in my old one. PCV is going to a catch can vented to atmos. yea compression after the new cams was 130 all aboard. AEB motor doesn't have SAI/combi valve or a suction jet pump. The AEB vacuum system is very simple, it doesn't have the n249 and all that crap of a mess, it just has a few check valves going to pcv and evap. I don't think I hooked up the vacuum system wrong All i took out was the evap port that goes into the TIP from the evap solenoid and that is capped off, PCV is going to catch can instead of TIP. and the on other side of engine bay another evap port capped off that comes from a ball canister in fender well. I think i got bent valves with the wrong cam timing thats the only thing that would make sense at this point, like somehow it got running worse. without promaf plugged in it wont even start

[B5carl]

130 on all four doesn't sound to bad if it's consistent but it's pretty low Idk what the normal pressure rating is. on vwvortex some guy said 160-190 is normal. Probably not bent valves.

If resetting ecu doesn't do it idk. Sounds like you replaced everything so its probably the tune or low fuel pressure but you replaced the pump and filter already so idk you might have to hook up a gauge near the fuel rail to see where it's at on idle.

Idk what the machine shop would do besides rebuild it and get it make full compression but to be honest I really don't know if 130 is that low to cause misfiring like the way you describe it.

You could just re-hone it yourself the manual tells you exactly how to do it.

I just did a quick search and some guys on here said 170+. You have to let it crank at least 7 times apparently. He was also getting low results in the 110-130 range

[B5carl]

Has to be something with the tune at this point. If all your getting is 130 then I wouldn't assume bent valves. Alot of people on here are saying when they bent a valve or valves they got no compression at all or much lower than 130.

I'd bring it to a tuner to get a custom tune done before id go through all that work pulling the motor out and paying a machine shop to rebuild it for no reason. if it's misfiring but has compression it has to be something electronic. Your timing looks good and those cams should be around 10inHg not positive though you can contact IE support and see what the vacuum pressure should be.

Also did you remove the trigger wheel from the crankshaft when you did the rebuild? It could be loose or positioned in the wrong orientation. I'm not sure if it only goes on one way kind of like the flywheel.

[QuattroBucc]

Has to be something with the tune at this point. If all your getting is 130 then I wouldn't assume bent valves. Alot of people on here are saying when they bent a valve or valves they got no compression at all or much lower than 130.

I'd bring it to a tuner to get a custom tune done before id go through all that work pulling the motor out and paying a machine shop to rebuild it for no reason. if it's misfiring but has compression it has to be something electronic. Your timing looks good and those cams should be around 10inHg not positive though you can contact IE support and see what the vacuum pressure should be.

Check the plugs to make sure they aren't fouled out.

Also did you remove the trigger wheel from the crankshaft when you did the rebuild? It could be loose maybe if you did.

Yea idk what it could be, I might have a machine shop just rebuild the head tho, im not very happy with 130 compression on a build with new valves new pistons new rings all that, it should be as close to 200 as possible like 190 on a new build, I wonder how much power I'd be leaving on the table settling for 130 compression over 190. I found that it got to max compression after 4 cranks , any more than that it didnt go up any more. The tune is a united motorsports stage 4 so Idk how to reset the ecu other than disconnect its power source. I had the fuel pump already in the car before this new build its an AEM 320lph one so I know that's been working and shouldn't of changed. It doesn't seem like its lacking Fuel at idle really Would I have to get a mechanical adjustable FPR to see that? the ones that have the gauge on them. The new cams are pulling less vacuum than the SPA ones which doesn't really make sense since the specs on the SPA have more peak lift, more duration under lift and more overlap between intake and exhaust. But I don't even want to let it sit and "idle" because the misfire counter is going up and up like every combustion cycle is a misfire so I turn the car off I don't want it to destroy the new engine if it hasn't already. Plugs aren't fouled either and No i never removed the trigger wheel. Whats really weird is when I first swapped the cams the 1st startup seemed promising it idled steady for a minute or so then I gave it a little rev to 2k and then it instantly started misfiring way worse and horrible since then almost like that rev somehow bent valves but if it was idling fine why would a little rev suddenly make it run like shit. I then cleared codes and reset Throttle body alignment because I remembered I hadn't cleared them since the SPA cams so It still had the LTFT in it, after cleared that it still idled like complete shit and misfiring every combustion cycle almost like its firing at the wrong time or none of the valves or sealing or are bent. But if all valves were bent It wouldn't even get up to 130 compression I think. Idk I'm so lost at this point , if it was crank pos sensor or cam pos sensor wouldn't they throw codes?

[B5carl]

See my next post

[B5carl]

Yea idk what it could be, I might have a machine shop just rebuild the head tho, im not very happy with 130 compression on a build with new valves new pistons new rings all that, it should be as close to 200 as possible like 190 on a new build, I wonder how much power I'd be leaving on the table settling for 130 compression over 190. I found that it got to max compression after 4 cranks , any more than that it didnt go up any more. The tune is a united motorsports stage 4 so Idk how to reset the ecu other than disconnect its power source. I had the fuel pump already in the car before this new build its an AEM 320lph one so I know that's been working and shouldn't of changed. It doesn't seem like its lacking Fuel at idle really Would I have to get a mechanical adjustable FPR to see that? the ones that have the gauge on them. The new cams are pulling less vacuum than the SPA ones which doesn't really make sense since the specs on the SPA have more peak lift, more duration under lift and more overlap between intake and exhaust. But I don't even want to let it sit and "idle" because the misfire counter is going up and up like every combustion cycle is a misfire so I turn the car off I don't want it to destroy the new engine if it hasn't already. Plugs aren't fouled either and No i never removed the trigger wheel. Whats really weird is when I first swapped the cams the 1st startup seemed promising it idled steady for a minute or so then I gave it a little rev to 2k and then it instantly started misfiring way worse and horrible since then almost like that rev somehow bent valves but if it was idling fine why would a little rev suddenly make it run like shit. I then cleared codes and reset Throttle body alignment because I remembered I hadn't cleared them since the SPA cams so It still had the LTFT in it, after cleared that it still idled like complete shit and misfiring every combustion cycle almost like its firing at the wrong time or none of the valves or sealing or are bent. But if all valves were bent It wouldn't even get up to 130 compression I think. Idk I'm so lost at this point , if it was crank pos sensor or cam pos sensor wouldn't they throw codes?

I got confused because you said it ran like crap after you swapped the cams then you said that it ran steady for a minute, then you reved it and it got worse. I know theres a procedure for resetting an ecu. If you did that to any car it would do the same thing.

Idk what the Audi procedure is but I think your suppose to warm it up to operating temp then shut it off and reset the ecu and throttle body, then turn it back on when it's fully warmed up and let it idle on its own for like 15 minutes. DONT rev it, try to drive it around so it can start recording a normal trim (shift over 2.5k rpm) and after about 20 minutes of driving bring it back to your house or a safe spot Incase it misfires again then rev it again and see if it wants to stay steady. It probably won't drop like it did but should be able to recalibrate with some normal driving in the trim. And the more you drive the better it should get. I'm surprised united motorsports didnt give you a guideline on how to properly set up a trim. I think that might do the trick.

My Honda did the same exact thing when I did that after I reset the ecu. It didn't misfire right off the bat but the idle dropped significantly like almost stalling out. Terrible for the engine btw

Ignore the stuff I said about testing it with a timing gun. I think that ruled out your harness being damaged

[Blazius]

130 psi is below the main limit , 130 psi =8.9 bar, rebuild min limit = 9 bar.

I am not sure what could you have messed up so bad that you got so low compression. Guess its the valves, were they lapped?

Btw for ecu reset , just disconnect the battery, but this a motor failure, 130 PSI is too low.

[QuattroBucc]

130 psi is below the main limit , 130 psi =8.9 bar, rebuild min limit = 9 bar.

I am not sure what could you have messed up so bad that you got so low compression. Guess its the valves, were they lapped?

Btw for ecu reset , just disconnect the battery, but this a motor failure, 130 PSI is too low.

Im not sure what I messed up either, all the valves were lapped in and then water tested overnight with zero leakage.... I think the only option now is have the head rebuilt and I don't want to do it myself this time Lol. Much nicer to Have all the responsibility on a machine shop to build it right. Because it'd be drive-able at 130 compression but not good.... I don't want to start a new BT build off with low compression.. because compression will just get worse over time.

[QuattroBucc]

I got confused because you said it ran like crap after you swapped the cams then you said that it ran steady for a minute, then you reved it and it got worse. I know theres a procedure for resetting an ecu. If you did that to any car it would do the same thing.

Idk what the Audi procedure is but I think your suppose to warm it up to operating temp then shut it off and reset the ecu and throttle body, then turn it back on when it's fully warmed up and let it idle on its own for like 15 minutes. DONT rev it, try to drive it around so it can start recording a normal trim (shift over 2.5k rpm) and after about 20 minutes of driving bring it back to your house or a safe spot Incase it misfires again then rev it again and see if it wants to stay steady. It probably won't drop like it did but should be able to recalibrate with some normal driving in the trim. And the more you drive the better it should get. I'm surprised united motorsports didnt give you a guideline on how to properly set up a trim. I think that might do the trick.

My Honda did the same exact thing when I did that after I reset the ecu. It didn't misfire right off the bat but the idle dropped significantly like almost stalling out. Terrible for the engine btw

Ignore the stuff I said about testing it with a timing gun. I think that ruled out your harness being damaged

My mistake, i meant it ran steady for a minute with the new I.E. cams still on the LTFT from the SPA cams idling, then i revv'd it after a min and it instantly started idling like shit and misfiring, idle went from -11 to -8 and then i reset ecu and did a TBA and it stayed shit. This procedure isn't really feasible because i'm not comfortable even letting it idle up to temperature it is literally misfiring every combustion cycle like on block 015 and 016 every single cylinder is misfiring every second and every bank is at 20+ misfires within a few seconds.

[B5carl]

My mistake, i meant it ran steady for a minute with the new I.E. cams still on the LTFT from the SPA cams idling, then i revv'd it after a min and it instantly started idling like shit and misfiring, idle went from -11 to -8 and then i reset ecu and did a TBA and it stayed shit. This procedure isn't really feasible because i'm not comfortable even letting it idle up to temperature it is literally misfiring every combustion cycle like on block 015 and 016 every single cylinder is misfiring every second and every bank is at 20+ misfires within a few seconds.I see what you mean now. But I'd try to get it running smoothly before the rebuild because it should still run at 130. Hopefully the machine shop catches the problem. I really don't know what it could be at this point.

[Blazius]

Its either a massive mistime or wrong pistons used, too thick HG etc. , compression drop on purpose etc.

[B5carl]

I just did a quick Google search and a source is saying that once your cylinder gets lower than 90 psi it could cause misfiring.

If you think your engine is damaged now from how it runs then it's just gonna get screwed up again if you don't figure out why its misfiring.

Make sure your resetting the throttle body to the proper position. If your throttle body isn't adjusted correctly then it will also cause it to misfire. I'm on united motorsports now and it doesn't say anything about having to mess with stock throttle body adjustment. Idk if resetting it messed with it's old stock positioning

And if you have an AEB how do you have a electronic throttle body? I thought they were all cable throttles?

[B5carl]

You should get one of those snake cameras and stick it into the spark plug hole to see if the Pistons are dented.

[QuattroBucc]

Its either a massive mistime or wrong pistons used, too thick HG etc. , compression drop on purpose etc.

OEM AEB unused pistons were installed with oem rings, cometic head gasket normal size used... and heres my timing https://imgur.com/a/fGGFrbD - it looks correct to me

[QuattroBucc]

I just did a quick Google search and a source is saying that once your cylinder gets lower than 90 psi it could cause misfiring.

If you think your engine is damaged now from how it runs then it's just gonna get screwed up again if you don't figure out why its misfiring.

Make sure your resetting the throttle body to the proper position. If your throttle body isn't adjusted correctly then it will also cause it to misfire. I'm on united motorsports now and it doesn't say anything about having to mess with stock throttle body adjustment. Idk if resetting it messed with it's old stock positioning

And if you have an AEB how do you have a electronic throttle body? I thought they were all cable throttles?

it is a cable throttle but through vagcom it still does a throttle body alignment somehow, idk it goes through throttle body % and voltages and adjusts it. im not physically adjusting it lol..... Its a normal thing to do a TBA anytime you reset codes or switch tunes..... resetting it does not messup anything.

[B5carl]

it is a cable throttle but through vagcom it still does a throttle body alignment somehow, idk it goes through throttle body % and voltages and adjusts it. im not physically adjusting it lol..... Its a normal thing to do a TBA anytime you reset codes or switch tunes..... resetting it does not messup anything.So the cable only adjust the idle. if there are no wires hooked up to your throttle body then it probably measures airflow through the ProMAF and uses it as a reference point for guessing how open the throttle valve is, assuming no leaks from the MAF sensor to the cylinder ports.

So if your throttle has been adjusted then it won't be in the correct position as the ecu thinks it's in. If the idle seems low then maybe try increasing the idle. Maybe it's not getting enough air. That would definitely cause misfiring if it's thinking that it's getting a certain amount of air and the throttle valve is not even adjusted to match what the ecu thinks it's at.

It's your foot pulling a throttle cable which pulls a spring loaded valve on the throttle body. No computer pulling on the cable to tell it what to do.

What your assuming the throttle body knows and what the ecu knows makes no sense. How would the throttle body know it's been reset if there's no electronics in it to adjust? Thats why dbw throttle body is way better it automatically syncs with what the ecu tells it electronicly through a stepper motor and is aligned from factory assembly.

If you reset it and you have upgraded cams, less air restrictions etc like the ProMAF and adjusted the throttle body yourself without any references then it could be shut to far closed. You also said you installed a new one so it probably needs to be adjusted by hand. I would try to hold the cold Idle at 1k RPM if its below that. The injectors probably can't keep up with what the ecu is telling it to spray and ACTUAL throttle body position vs the ecu reset position. Give it a try.

If your gonna get a rebuild then why not I wouldn't worry about compression. 130 should be good for now thats not low enough to cause misfiring.

If you have good oil pressure then it probably doesnt have much damage. It really only matters if you have low pressure and a slow idle like below 850rpm, which would cause low pressure.

[QuattroBucc]

So the cable only adjust the idle. if there are no wires hooked up to your throttle body then it probably measures airflow through the ProMAF and uses it as a reference point for guessing how open the throttle valve is, assuming no leaks from the MAF sensor to the cylinder ports.

So if your throttle has been adjusted then it won't be in the correct position as the ecu thinks it's in. If the idle seems low then maybe try increasing the idle. Maybe it's not getting enough air. That would definitely cause misfiring if it's thinking that it's getting a certain amount of air and the throttle valve is not even adjusted to match what the ecu thinks it's at.

It's your foot pulling a throttle cable which pulls a spring loaded valve on the throttle body. No computer pulling on the cable to tell it what to do.

What your assuming the throttle body knows and what the ecu knows makes no sense. How would the throttle body know it's been reset if there's no electronics in it to adjust? Thats why dbw throttle body is way better it automatically syncs with what the ecu tells it electronicly through a stepper motor and is aligned from factory assembly.

If you reset it and you have upgraded cams, less air restrictions etc like the ProMAF and adjusted the throttle body yourself without any references then it could be shut to far closed. You also said you installed a new one so it probably needs to be adjusted by hand. I would try to hold the cold Idle at 1k RPM if its below that. The injectors probably can't keep up with what the ecu is telling it to spray and ACTUAL throttle body position vs the ecu reset position. Give it a try.

If your gonna get a rebuild then why not I wouldn't worry about compression. 130 should be good for now thats not low enough to cause misfiring.

If you have good oil pressure then it probably doesnt have much damage. It really only matters if you have low pressure and a slow idle like below 850rpm, which would cause low pressure.

The cable throttle still has wires, it has a TPS attached to the throttlebody so it reads your throttle %, pretty sure there is still a motor in the cable throttle because when i do a TBA through vagcom it pulls the physical pedal tightly to 0 slack and i hear the throttlebody moving inside. Exactly what your saying is the whole point of doing a TBA, so that it is at the correct throttle % open at idle. The Cable throttle still has wiring and sensors, These are not carburetors lol there is no physical adjustment to them besides making sure the actual cable doesn't have slack to it .... what you said about the throttlebody and ecu not knowing the throttle % isn't the case, the ecu knows the throttle % the cable throttle still has a TPS. I actually highly prefer the feel/linear of the cable throttle, I also have a 04 GLI thats dbw and the pedal is just so numb and you get zero feedback from the road into the pedal. with the cable throttle you feel the engine actually rev up through the pedal feel etc it feels really nice.

all that doing a TBA through vagcom does is verifies the throttle % is correct and that the throttlebody can move through all the throttle %'s and voltages and is in working order . Oil pressure is good, before when it actually could idle up to temp with the SPA cams but not driveable cuz it would misfire it had 25 psi fully warm at idle and goes up a lot with revs.

[B5carl]

The cable throttle still has wires, it has a TPS attached to the throttlebody so it reads your throttle %, pretty sure there is still a motor in the cable throttle because when i do a TBA through vagcom it pulls the physical pedal tightly to 0 slack and i hear the throttlebody moving inside. Exactly what your saying is the whole point of doing a TBA, so that it is at the correct throttle % open at idle. The Cable throttle still has wiring and sensors, These are not carburetors lol there is no physical adjustment to them besides making sure the actual cable doesn't have slack to it .... what you said about the throttlebody and ecu not knowing the throttle % isn't the case, the ecu knows the throttle % the cable throttle still has a TPS. I actually highly prefer the feel/linear of the cable throttle, I also have a 04 GLI thats dbw and the pedal is just so numb and you get zero feedback from the road into the pedal. with the cable throttle you feel the engine actually rev up through the pedal feel etc it feels really nice.

all that doing a TBA through vagcom does is verifies the throttle % is correct and that the throttlebody can move through all the throttle %'s and voltages and is in working order . Oil pressure is good, before when it actually could idle up to temp with the SPA cams but not driveable cuz it would misfire it had 25 psi fully warm at idle and goes up a lot with revs.Damn I was under the impression that it was alot simpler than mine. I have a 01 AWM with wideband and dbw so I didnt study much detail on the AEB. Is there a TPS attached to foot pedal also? I forget the actual name but it measures throttle position on the foot pedal. Maybe that might also need to be reset?

You also said it drove nice over 25% throttle so it has to be tune issue

[B5carl]

I think you should ditch the united motorsports tune keep the ProMAF or ditch it also for a VR6 or S4, RS4 MAF and bring it to a tuner before you pull the motor.

[Blazius]

Mate , it does not really matter what is the issue, that low of compression is a nono for 9.5CR

[QuattroBucc]

Damn I was under the impression that it was alot simpler than mine. I have a 01 AWM with wideband and dbw so I didnt study much detail on the AEB. Is there a TPS attached to foot pedal also? I forget the actual name but it measures throttle position on the foot pedal. Maybe that might also need to be reset?

You also said it drove nice over 25% throttle so it has to be tune issue

idk vacuum leaks can act like that, drive fine over 25% throttle also. thats what I thought it was before

- - - Updated - - -


I think you should ditch the united motorsports tune keep the ProMAF or ditch it also for a VR6 or S4, RS4 MAF and bring it to a tuner before you pull the motor.

Idk nobody seems to have ANY issues with the tune like zero hiccups at all, just a great tune out the box, the only problem people have is when they start wanting more power they have to go custom tune.

- - - Updated - - -


Mate , it does not really matter what is the issue, that low of compression is a nono for 9.5CR

Yeah thats how I'm feeling, the head needs to be rebuilt anyways. I don't want to start out at the rebuild limit

[B5carl]

idk vacuum leaks can act like that, drive fine over 25% throttle also. thats what I thought it was before

- - - Updated - - -



Idk nobody seems to have ANY issues with the tune like zero hiccups at all, just a great tune out the box, the only problem people have is when they start wanting more power they have to go custom tune.

- - - Updated - - -



Yeah thats how I'm feeling, the head needs to be rebuilt anyways. I don't want to start out at the rebuild limitDo what you gotta do man. Id like to see where this build goes

[QuattroBucc]

Do what you gotta do man. Id like to see where this build goes

yea I guess Ill throw my fully stock aeb head on it from the working motor i pulled out because that head should work..... if everything else is in working order, bit dirty lol 210k miles on that motor, tons of carbon on the exhaust valves i saw when i pulled the exh mani off. The built head will probably be at machine shop for a bit, theres only 2 in town and they are always stacked up with work

[B5carl]

Cool, keep us updated

[QuattroBucc]

Cool, keep us updated

you think i can re-use the Head gasket since theres really no miles or load been on it?

[B5carl]

you think i can re-use the Head gasket since theres really no miles or load been on it?To be honest idk because the inside is like a crush washer that only is supposed to get used once. I've also heard of Honda guys literally painting the gasket with copper to act as an external crush washer.

If it was me and you have ARP resusable hardware then why not but its gonna have a higher chance of leaking for sure

[QuattroBucc]

To be honest idk because the inside is like a crush washer that only is supposed to get used once. I've also heard of Honda guys literally painting the gasket with copper to act as an external crush washer.

If it was me and you have ARP resusable hardware then why not but its gonna have a higher chance of leaking for sure

well I'm gonna have to pull the head off AGAIN when I get the head back from the machine shop so this HG will only be on for 2 months or so. yea that copper gasket spray is mainly used when you're re-using a HG I've heard it works for tons of people even on high hp applications.

[B5carl]

well I'm gonna have to pull the head off AGAIN when I get the head back from the machine shop so this HG will only be on for 2 months or so. yea that copper gasket spray is mainly used when you're re-using a HG I've heard it works for tons of people even on high hp applications.What brand head gasket is it?

[QuattroBucc]

What brand head gasket is it?

cometic, its a MLS gasket. I've heard you can re-use MLS gaskets with that copper spray, cuz on MLS gaskets the black viton layer is what comes off, so you replace that with copper spray and apparently it works? Lots of dragsters that always are taking their motors apart re-use their MLS gaskets with copper spray so I'll probably give that a go

[Blazius]

I would not reuse a headgasket ever. Once it was torqued and compressed it will never be the same.

Those dragsters only need to do one run if that. 2 months is a long time.

[QuattroBucc]

I would not reuse a headgasket ever. Once it was torqued and compressed it will never be the same.

Those dragsters only need to do one run if that. 2 months is a long time.

damn I guess Fel-Pro from autozone it is then lol should hold up just breaking the motor in

[QuattroBucc]

I would not reuse a headgasket ever. Once it was torqued and compressed it will never be the same.

Those dragsters only need to do one run if that. 2 months is a long time.

Got the Stock head on today and starts right up no problems, once it learned the idle lambda it idles super smooth no misfires. So now to Plan what to do with the built head, I see nothing wrong with it so i don't really know where to start. The timing marks on the built head vs the stock head I just put on are in exactly the same spots so I don't know why the built head was having timing issues. Should I just go all out with this head since its going to be at the machine shop anyways and they're going to have to relap/reassemble. I already have inconel exhaust valves but I could go +1mm oversized intake and get a 5 angle valve seat job to maximize CFM. Or should I just have them test for leaks and relap/reassemble

[B5carl]

So the head was leaking

[QuattroBucc]

So the head was leaking

I still have no idea because the head looks picture perfect but thats all I can think of really.

Update the car is still not driveable on the road, just like before it is misfiring and going crazy at part throttle..... so maybe the other head was not the problem at all. fuuuuarkkkk where do I go from here, is it the ProMaf, the o2 sensors or the tune itself

[B5carl]

I still have no idea because the head looks picture perfect but thats all I can think of really.

Update the car is still not driveable on the road, just like before it is misfiring and going crazy at part throttle..... so maybe the other head was not the problem at all. fuuuuarkkkk where do I go from here, is it the ProMaf, the o2 sensors or the tune itselfI'd try another tune before machine shop work. Check compression with the new head though to see if it's not in the 130 range

[QuattroBucc]

I'd try another tune before machine shop work. Check compression with the new head though to see if it's not in the 130 range

just did a compression check with "old" head checked out at 160 all 4 cylinders. this damn problem is driving me crazy i want to drive my car lol

[B5carl]

just did a compression check with "old" head checked out at 160 all 4 cylinders. this damn problem is driving me crazy i want to drive my car lolAll I can imagine it being is the tune. Maybe the ProMAF isnt hooked up correctly. I'd ditch it and use the stock sensor with a new tune.

[QuattroBucc]

All I can imagine it being is the tune. Maybe the ProMAF isnt hooked up correctly. I'd ditch it and use the stock sensor with a new tune.

Originally the Promaf wasn't hooked up correctly and the signal wire was getting 5 volts like the v8 maf would, i fixed that but fred @united motorsports was worried that maybe that killed the maf, but he says with the normal idle readings that it should be working fine.... what would you go with? there's not much out there for the AEB 1.8 narrowband ecu. I already ditched eurodyne tuning suite because there was zero support/advice for the AEB anymore

[B5carl]

Originally the Promaf wasn't hooked up correctly and the signal wire was getting 5 volts like the v8 maf would, i fixed that but fred @united motorsports was worried that maybe that killed the maf, but he says with the normal idle readings that it should be working fine.... what would you go with? there's not much out there for the AEB 1.8 narrowband ecu. I already ditched eurodyne tuning suite because there was zero support/advice for the AEB anymoreI have no idea maybe @Blazius can steer you in that direction. I'm planning on using a motoza custom base file then finding a new england Audi tuner to touch it up. At this point I don't plan on using ProMAF.


Most people either use the VR6 or mafless. I'm using VR6 but probably more options. You can also find aluminum 3"+ adapters on ebay specifically for our cars.

https://www.ebay.com/itm/3-0-OD-MAF-Mass-Air-Flow-Housing-for-VW-MK4-MK5-Audi-Volvo-Mercedes-BMW-/252453159821?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=711-127632-2357-0

[QuattroBucc]

I have no idea maybe @Blazius can steer you in that direction. I'm planning on using a motoza custom base file then finding a new england Audi tuner to touch it up. At this point I don't plan on using ProMAF.


Most people either use the VR6 or mafless. I'm using VR6 but probably more options. You can also find aluminum 3"+ adapters on ebay specifically for our cars.

https://www.ebay.com/itm/3-0-OD-MAF-Mass-Air-Flow-Housing-for-VW-MK4-MK5-Audi-Volvo-Mercedes-BMW-/252453159821?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=711-127632-2357-0

He will say to learn the software and tune it myself because nothing can control the motor like the stock motronic can, but I do not want to dive into that world of tuning. And AEB cannot run mafless it is narrowband it doesn't have a MAP sensor or wideband linked to the ecu. my wideband is just for monitoring-it doesn't tie into my ecu at all. AEB are controlled by maf and AIT mostly so the MAF being super accurate is a MUST because we dont have a backup MAP and wideband to stabilize AFR. I don't think promaf is a MUST at all- the maf readings don't seem any more 'stable' than normal maf its marketed as "having 360 degree profiling" but it looks just like a normal maf with the protruding hotwire, its just what united motorsports tune calls for. At this point it has to be the maf or the tune itself, i don't think even a bad o2 sensor would make it undriveable. I'm gonna be pissed if it was the maf all along and the tuner couldn't figure that out even when i'm telling him how i had it wired wrong before and he worries it might've killed the maf. But I'm not too keen on ditching this tune also and looking for another- most people looove the united motorsports tunes- im guessing it is a hardware issue- even the injectors could be defective, who really knows at this point. but hopefully I can get it figured out soon...

[B5carl]

He will say to learn the software and tune it myself because nothing can control the motor like the stock motronic can, but I do not want to dive into that world of tuning. And AEB cannot run mafless it is narrowband it doesn't have a MAP sensor or wideband linked to the ecu. my wideband is just for monitoring-it doesn't tie into my ecu at all. AEB are controlled by maf and AIT mostly so the MAF being super accurate is a MUST because we dont have a backup MAP and wideband to stabilize AFR. I don't think promaf is a MUST at all- the maf readings don't seem any more 'stable' than normal maf its marketed as "having 360 degree profiling" but it looks just like a normal maf with the protruding hotwire, its just what united motorsports tune calls for. At this point it has to be the maf or the tune itself, i don't think even a bad o2 sensor would make it undriveable. I'm gonna be pissed if it was the maf all along and the tuner couldn't figure that out even when i'm telling him how i had it wired wrong before and he worries it might've killed the maf. But I'm not too keen on ditching this tune also and looking for another- most people looove the united motorsports tunes- im guessing it is a hardware issue- even the injectors could be defective, who really knows at this point. but hopefully I can get it figured out soon...Damn man idk at this point either [emoji29]

[QuattroBucc]

Damn man idk at this point either [emoji29]

yea idk either, but you and blazius have been a world of help with trying to figure it out.

[B5carl]

yea idk either, but you and blazius have been a world of help with trying to figure it out. Also with the 130 compression with big cams that might not be that low because i was doing some research and with big cams with overlap they don't test as high of compression because you're getting losing some pressure out of the valves, I really only found forums of people talking about this with LS and small blocks but I'm sure it applies to any big cam with overlap. I wonder what 1.8t builds with the I.E. cams actually compression test at on a 100% air leak proof motorYou can email them an ask I'm sure that guy Zane knows alot he gave me some good info on the adjustable cam gear and VVT

[QuattroBucc]

You can email them an ask I'm sure that guy Zane knows alot he gave me some good info on the adjustable cam gear and VVT

scratch that- found more info the overlap doesn't affect the compression test so 130 is definitely low. Dang I wish I built a wide band car instead of the AEB. they drive much better due to having map sensor and wideband and so much more support and availability for tunes. But I'm stuck with what I got now.... just have to get the damn car to work

[B5carl]

scratch that- found more info the overlap doesn't affect the compression test so 130 is definitely low. Dang I wish I built a wide band car instead of the AEB. they drive much better due to having map sensor and wideband and so much more support and availability for tunes. But I'm stuck with what I got now.... just have to get the damn car to workMaybe try swapping the o2 sensor with your old one

[B5carl]

Another question to ask if you swap your MAF is does it need of be tuned in? So far I haven't heard of people having problems with upgrading to a bigger MAF but I'm guessing the MAF for that specific car has a certain amount of air flowing through it so if you upgraded the MAF how would it know that there's more air flowing through it?


Just to verify, you hooked up all 4 wires from the ProMAF right?

[Blazius]

No, i wont tell you to go learn and do it yourself it has be something you choose to do. But dont get me wrong ot is not easy it would take a few months to get basics with Motronic, you have to understand these ecus specially ME7 was probably the most advanced for that period.

Yes, any change you make to maf has to be reflected in the calibration if you dont the car wont run right.

Motronics main load input is MAF always, you CANNOT remove it without changes. These cars dont have a MAP , they have a thrust sensor as Bosch likes to call it, a boost sensor, without MAF the car runs on alpha N something to get you home in limp, not proper spees density with actual map, I can probably count on one hand who can do this on me7.
Also a maf system is the fastest and most accurate system for fueling.

Still 160 compression to me is a bit meh on a full rebuild , do a wet test it will tell you if its the block or head.

[QuattroBucc]

No, i wont tell you to go learn and do it yourself it has be something you choose to do. But dont get me wrong ot is not easy it would take a few months to get basics with Motronic, you have to understand these ecus specially ME7 was probably the most advanced for that period.

Yes, any change you make to maf has to be reflected in the calibration if you dont the car wont run right.

Motronics main load input is MAF always, you CANNOT remove it without changes. These cars dont have a MAP , they have a thrust sensor as Bosch likes to call it, a boost sensor, without MAF the car runs on alpha N something to get you home in limp, not proper spees density with actual map, I can probably count on one hand who can do this on me7.
Also a maf system is the fastest and most accurate system for fueling.

Still 160 compression to me is a bit meh on a full rebuild , do a wet test it will tell you if its the block or head.

the 160 compression is with the OLD unbuilt head on though so only the bottom end is built so isn't 160 pretty good in that case?

and to B5carl yes All diff size mafs have to be scaled correct because with the larger diaemeter the hotwire reads less airflow so the numbers have to be scaled differently. and yes all 4 wires are wired in correctly lol.... I'm not stupid as much as this forum may make it seem

[B5carl]

the 160 compression is with the OLD unbuilt head on though so only the bottom end is built so isn't 160 pretty good in that case?

and to B5carl yes All diff size mafs have to be scaled correct because with the larger diaemeter the hotwire reads less airflow so the numbers have to be scaled differently. and yes all 4 wires are wired in correctly lol.... I'm not stupid as much as this forum may make it seemNaa I'm just making sure. I don't think the ProMAF is causing these problems but it can't be compression at this point, 160 should still run fine.

You also said that it ran good for a little after you started it with the other head. Did the throttle cut out at all while you were driving it? You still haven't checked fuel pressure yet right?

I forget whether you said the AEB has a PCV or not but here's what I found on Google. I remember people having idle issues with the 034 PCV and it sounds similar to what's going on with your car. You probably have a stock but it might be stuck:

245895
245896

[B5carl]

As you can see in the picture if that valve is stuck open then there's your vaccum leak. I wouldn't delete it at this point because it could be the source of all this issues with it idling rough and will cause excessive pressure to build up in the crankcase and blow through seals. It acts as another bypass under boost. I'm not a pro at PCV diagnostics but I wouldn't delete anything after a build until I know the car is running correctly to begin with especially with a new tune

From what I know the valve isn't supposed to be fully shut so you can blow through both ends but it restricts the system from letting crank case pressure from dropping to low. If I'm correct then that will also cause low oil pressure. You should also have a oil pressure gauge hooked up to. Here are the specs for idle on a 1.8t:

Oil Pressure
Cold Idle: ~80 psi
Cold 2k rpms: ~90 psi
Cold 3k rpms: ~100psi (pegs the gauge)
Hot Idle: ~24 psi
Hot 2k rpms: ~50 psi
Hot 3k rpms: ~70 psi
Hot at redline can still peg the gauge (100 psi)

IECVA2 Cams Vaccum at idle: ~10inHg


245897

[QuattroBucc]

As you can see in the picture if that valve is stuck open then there's your vaccum leak. I wouldn't delete it at this point because it could be the source of all this issues with it idling rough and will cause excessive pressure to build up in the crankcase and blow through seals. It acts as another bypass under boost. I'm not a pro at PCV diagnostics but I wouldn't delete anything after a build until I know the car is running correctly to begin with especially with a new tune

From what I know the valve isn't supposed to be fully shut so you can blow through both ends but it restricts the system from letting crank case pressure from dropping to low. If I'm correct then that will also cause low oil pressure. You should also have a oil pressure gauge hooked up to. Here are the specs for idle on a 1.8t:

Oil Pressure
Cold Idle: ~80 psi
Cold 2k rpms: ~90 psi
Cold 3k rpms: ~100psi (pegs the gauge)
Hot Idle: ~24 psi
Hot 2k rpms: ~50 psi
Hot 3k rpms: ~70 psi
Hot at redline can still peg the gauge (100 psi)

IECVA2 Cams Vaccum at idle: ~10inHg


245897

I haven't checked fuel pressure but pretty damn sure thats definitely not it. its weird, i can drive up and down my street in 1st/2nd gear just fine no misfires or bogging but once im goin 30-40 in 3rd and 4th just maintaining speed it doesn't like it and AFR starts going pig rich down to 10 which is the lowest the aem guage reads, then up to 17 the highest it reads, off the scale, back to 10, so i get off the throttle and downshift to 2nd and give over 25% throttle where AFRs are not misfiring on the short way home , over 25% throttle it feels fine starts to get into some boost- if fuel pressure was an issue I don't think it would do that. yes AEB has a PCV but for aeb its muuuuch simpler than 01 cars with the SAI and combi valve, I stated before its deleted and the block breather is going to a catch can vented to atmos along with the valve cover. I used an updated valve cover since the aeb one doesn't have a breather. People were having those issues only when its still routed into your vacuum system because it was having leaks, if its completely out of your vacuum system you can just run a Hose to behind the axles. deleting it doesn't build up excess pressure its routed to a catch can where it breathes freely, I don't think deleting it is related to this in any way. I do have an oil pressure guage hooked up... stated before it was good oil pressure 25 at warm idle about 90 at cold startup

[B5carl]

I haven't checked fuel pressure but pretty damn sure thats definitely not it. its weird, i can drive up and down my street in 1st/2nd gear just fine no misfires or bogging but once im goin 30-40 in 3rd and 4th just maintaining speed it doesn't like it and AFR starts going pig rich down to 10 which is the lowest the aem guage reads, then up to 17 the highest it reads, off the scale, back to 10, so i get off the throttle and downshift to 2nd and give over 25% throttle where AFRs are not misfiring on the short way home , over 25% throttle it feels fine starts to get into some boost- if fuel pressure was an issue I don't think it would do that. yes AEB has a PCV but for aeb its muuuuch simpler than 01 cars with the SAI and combi valve, I stated before its deleted and the block breather is going to a catch can vented to atmos along with the valve cover. I used an updated valve cover since the aeb one doesn't have a breather. People were having those issues only when its still routed into your vacuum system because it was having leaks, if its completely out of your vacuum system you can just run a Hose to behind the axles. deleting it doesn't build up excess pressure its routed to a catch can where it breathes freely, I don't think deleting it is related to this in any way. I do have an oil pressure guage hooked up... stated before it was good oil pressure 25 at warm idle about 90 at cold startupSo if the PCV is deleted I think you should hook it back up and see how it runs. It should be easy to do and doesn't hurt to try it out. Since it's responsible for controlling vacuum it's could be the source of the leak you've talked about since the beginning.

I use to have a 95 bmw 530i and it was extremely sensitive to vaccum leaks to the point where I would pull the dipstick while it was idling perfect and the idle would drop so low it would almost stall out. My civic does not do that if I pull the dipstick while it's running so every system is different.

[QuattroBucc]

So if the PCV is deleted I think you should hook it back up and see how it runs. It should be easy to do and doesn't hurt to try it out. Since it's responsible for controlling vacuum it's could be the source of the leak you've talked about since the beginning.

I use to have a 95 bmw 530i and it was extremely sensitive to vaccum leaks to the point where I would pull the dipstick while it was idling perfect and the idle would drop so low it would almost stall out. My civic does not do that if I pull the dipstick while it's running so every system is different.

Don't think that's really possibly in this case. the hockey puck pcv just uses vacuum from the TIP to pull the crankcase pressure out. I don't think the crankcase venting freely is a "vacuum leak". it would literally just be from the crankcase vent straight to hockey puck straight into TIP. that wouldn't do anything for my vacuum. and I can't just "hook it back up" anyways I would have to custom fit a new silicone or something 1" opening line into the custom TIP then and adding in a new line adds in the possibility for an actual vacuum leak. taking away the PCV hockey puck which just uses the combo of crankcase pressure and vacuum in the TIP to pull the crank fumes back into the air system does not induce a vacuum leak.
Right now vacuum is at -17 at idle which doesn't seem like a huge leak but before with the 210k motor the car would make -21 or -22 at idle so thats what I'm trying to get back to. I wonder if the external wastegate is possibility leaking through the stem

[B5carl]

Don't think that's really possibly in this case. the hockey puck pcv just uses vacuum from the TIP to pull the crankcase pressure out. I don't think the crankcase venting freely is a "vacuum leak". it would literally just be from the crankcase vent straight to hockey puck straight into TIP. that wouldn't do anything for my vacuum. and I can't just "hook it back up" anyways I would have to custom fit a new silicone or something 1" opening line into the custom TIP then and adding in a new line adds in the possibility for an actual vacuum leak. taking away the PCV hockey puck which just uses the combo of crankcase pressure and vacuum in the TIP to pull the crank fumes back into the air system does not induce a vacuum leak.
Right now vacuum is at -17 at idle which doesn't seem like a huge leak but before with the 210k motor the car would make -21 or -22 at idle so thats what I'm trying to get back to. I wonder if the external wastegate is possibility leaking through the stemI'm talking about the PCV not the PRV-pressure recirculation valve(hockey puck) that your referring to. I know the catch can can be used to replace the PRV but the PCV thats connected to the oil filter housing should not be deleted. I attached a picture in the above post not sure if you saw it.

And from what I know big cams are supposed to pull less vaccum depending on the cam profile. The stock car makes about the same as your old set up with stock so it's expected to drop with the cam upgrade

[QuattroBucc]

I'm talking about the PCV not the PRV-pressure recirculation valve(hockey puck) that your referring to. I know the catch can can be used to replace the PRV but the PCV thats connected to the oil filter housing should not be deleted. I attached a picture in the above post not sure if you saw it.

And from what I know big cams are supposed to pull less vaccum depending on the cam profile. The stock car makes about the same as your old set up with stock so it's expected to drop with the cam upgrade

those links don't work. but what im confused? the hockey puck IS the pcv. Are you talking about the billet Check valve? Theres no big cams in the car right now though, fully stock head so the vacuum should be the same as before this build, its the same head

[B5carl]

those links don't work. but what im confused? the hockey puck IS the pcv. Are you talking about the billet Check valve? Theres no big cams in the car right now though, fully stock head so the vacuum should be the same as before this build, its the same headYea the "check" valve but more commonly referred to as the bleeder valve. It's a 2 way valve not a one way check valve

[QuattroBucc]

Yea the "check" valve but more commonly referred to as the bleeder valve. It's a 2 way valve not a one way check valve

Well still that doesn't apply because my pcv is not linked back into the vacuum system in any way. Those people that got vacuum leaks from it is when its still hooked up into the whole vacuum system. I don't think my problems are related to me venting crankcase vents to catchcan, adding in that valve in-line to the catch can would just create more pressure in the crankcase at the minimum, not affect anything vacuum related though

[B5carl]

Then maybe your right. If there's no PCV then you would have higher vacuum pressure at idle. So if your getting a lower vaccum then it's leaking from somewhere.

If it's linked to the oil filter housing and valve cover which its supposed to be then it is connected it the vaccum system... I think you should try hooking the old on back on and see if it does anything at all.

[QuattroBucc]

Its vaccum not pressure im talking about. as you said it drives good at 25% throttle which im assuming is as boost starts to rise but the low rpm to idle will be affected.

Yea i getcha but why would deleting it and taking it out of the vacuum system create a vacuum leak? right now the TIP only has the divert valve port going into it, it has no other ports. only vacuum line on the manifold being used is one for the diverter valve, the brake booster, and the fuel pressure regulator to manifold, everything is sealed up. and yea it drives good when it gets to low vacuum and out of vacuum, then its just a boost leak lol

[Blazius]

You can dump the crankcase venting to atmosphere as long as you close up the system, as a bonus your engine will thank you. While it is technically a leak since even crankcase leakthrough has been measured it does not affect AFR in the slightest.

Did I read that right, you have the FPR vacuum line disconnected? And the brake booster too?

[B5carl]

Yea i getcha but why would deleting it and taking it out of the vacuum system create a vacuum leak? right now the TIP only has the divert valve port going into it, it has no other ports. only vacuum line on the manifold being used is one for the diverter valve, the brake booster, and the fuel pressure regulator to manifold, everything is sealed up. and yea it drives good when it gets to low vacuum and out of vacuum, then its just a boost leak lolIdk at this point lol I actually don't remember what the stock vaccum pressure is I haven't started my B5 in a while but now I remember I think it was near -15 to 20inHg or something like that bone stock. So Idk -17 sounds normal. When it warms up the vaccum will decrease to -15 etc. In that range

[Rmr1499]

I idle -19 to -21 on stock engine with 212k on it and on a cold compression check in at 140. I know I have bad exhaust valve as I smoke like a freight train on decel and idle at light. But I got spare engine on stand as we speak. But even with the 140psi compression still idles great and runs flawlessly minus the Smokeyness.


Sent from my iPhone using Audizine Forum (http://r.tapatalk.com/byo?rid=87676)

[QuattroBucc]

You can dump the crankcase venting to atmosphere as long as you close up the system, as a bonus your engine will thank you. While it is technically a leak since even crankcase leakthrough has been measured it does not affect AFR in the slightest.

Did I read that right, you have the FPR vacuum line disconnected? And the brake booster too?

No i meant thoes are the only vacuum lines I have right now lol, and the one from wastegate to intercooler line boost tap.

[QuattroBucc]

Idk at this point lol I actually don't remember what the stock vaccum pressure is I haven't started my B5 in a while but now I remember I think it was near -15 to 20inHg or something like that bone stock. So Idk -17 sounds normal. When it warms up the vaccum will decrease to -15 etc. In that range

well before the motor swap it idled at -21 or -22 so I feel like it should be that maybe?, with short term lambda bouncing around, AFR bouncing from low 14s to 15s at idle so its within range but definitely compensating for a leak somewhere like it adds fuel, goes to the low 14s then takes it away cuz its trying to maintain 14.7 afr.

ltft is at 11%

[B5carl]

well before the motor swap it idled at -21 or -22 so I feel like it should be that maybe?, with short term lambda bouncing around, AFR bouncing from low 14s to 15s at idle so its within range but definitely compensating for a leak somewhere like it adds fuel, goes to the low 14s then takes it away cuz its trying to maintain 14.7 afr.

ltft is at 11%Did you put new plugs in it after all that, they could be fouled

[QuattroBucc]

Did you put new plugs in it after all that, they could be fouled

Yes I did put new ones, bkr7e gapped to .028

[B5carl]

Yes I did put new ones, bkr7e gapped to .028Guess it's time to get a new tune

[Bstew]

Guess it's time to get a new tune


Not to hijack this thread but do you have any recommendations for a tune? I just did a BT install as well, along with a handful of other things. 01 A4 1.8t Quattro

QuattroBucc All I can says is I feel your pain. I’ve been chasing the same problems. It’s very frustrating!


Sent from my iPhone using Tapatalk

[B5carl]

Not to hijack this thread but do you have any recommendations for a tune? I just did a BT install as well, along with a handful of other things. 01 A4 1.8t Quattro

QuattroBucc All I can says is I feel your pain. I’ve been chasing the same problems. It’s very frustrating!


Sent from my iPhone using Tapatalk@Blazius can probably steer you in that direction. I haven't gotten my car tuned yet but I was planning on getting a motoza big turbo custom base then finding a local tuner to touch it up.

[B5carl]

Idk if you can see these pics but I just found this and guess it's probably not a bad idea to delete the PCV if he has no misfiring or idle issues246006

[QuattroBucc]

Idk if you can see these pics but I just found this and guess it's probably not a bad idea to delete the PCV if he has no misfiring or idle issues246006

My catch can is underneath the coolant overflow, completely hidden and way shorter lines to run

[QuattroBucc]

Not to hijack this thread but do you have any recommendations for a tune? I just did a BT install as well, along with a handful of other things. 01 A4 1.8t Quattro

QuattroBucc All I can says is I feel your pain. I’ve been chasing the same problems. It’s very frustrating!


Sent from my iPhone using Tapatalk

i've heard good things about http://tunedbygts.com/software/audi/a4-sw/b5-sw/b5-a4/a4-awm/bt-18t

[QuattroBucc]

Guess it's time to get a new tune

I really don't think its the tune, if it works flawless for everybody else why would it be bad for my car? I think its something hardware related like the MAF got fried when getting a constant 5v on the signal wire, or wastegate is leaking. @blazius do you know if an o2 sensor is really bad that it could be telling the car to adjust fueling completely wrong and make the afr bounce around constantly?? I have no codes for o2 sensors or anything else but I'm not too keen on just dishing out another $100 for a bosch o2 sensor if mine is working normal

[B5carl]

I really don't think its the tune, if it works flawless for everybody else why would it be bad for my car? I think its something hardware related like the MAF got fried when getting a constant 5v on the signal wire, or wastegate is leaking. @blazius do you know if an o2 sensor is really bad that it could be telling the car to adjust fueling completely wrong and make the afr bounce around constantly?? I have no codes for o2 sensors or anything else but I'm not too keen on just dishing out another $100 for a bosch o2 sensor if mine is working normalHave you tried the old throttle body yet or try reflashing the ECU? Check injector wiring

I just thought about what you did with the EVAP system. You capped it off completely from the tank right? So there's no flow of air going into the tank? The fuel pump could be trying to pump fuel but it's being restricted kind of like when you pour gas out of a gas tank it needs that bleeder hole to let the fuel pour out. Since the tank is sealed then it will struggle pumping fuel out. If it's sealed off as tight as I think it is then that alone would cause low fuel pressure.

[B5carl]

...

[QuattroBucc]

Have you tried the old throttle body yet or try reflashing the ECU? Check injector wiring

I just thought about what you did with the EVAP system. You capped it off completely from the tank right? So there's no flow of air going into the tank? The fuel pump could be trying to pump fuel but it's being restricted kind of like when you pour gas out of a gas tank it needs that bleeder hole to let the fuel pour out. Since the tank is sealed then it will struggle pumping fuel out. If it's sealed off as tight as I think it is then that alone would cause low fuel pressure.

haven't tried the old throttle body yet, and i cant reflash it, i had to mail the ecu to the tuner and he flashed it and sent it back. Uhmmm I don't know if its completely capped, the line that goes into the evap solenoid coming from the fender well i capped off, I just tried the car with it uncapped and it didn't change anything. But that does make me think, as I Tip in the gas afr goes up to 17 18 then comes back down, so it could be losing fuel pressure at the tip in of the gas pedal, or vacuum leak. Would opening up my gas cap to relieve pressure work as as test with that? Nope- just tried it, and opened the gas pump valve to see if there was pressure in the tank and there wasnt. I just ordered the ECS in-line fuel pressure guage. and I'm wondering if the tune is supposed to be used with the stock DBC 3 bar fpr or the newer 4 bar fpr, tuner didnt specify anything

[B5carl]

haven't tried the old throttle body yet, and i cant reflash it, i had to mail the ecu to the tuner and he flashed it and sent it back. Uhmmm I don't know if its completely capped, the line that goes into the evap solenoid coming from the fender well i capped off, I just tried the car with it uncapped and it didn't change anything. But that does make me think, as I Tip in the gas afr goes up to 17 18 then comes back down, so it could be losing fuel pressure at the tip in of the gas pedal, or vacuum leak. Would opening up my gas cap to relieve pressure work as as test with that? Nope- just tried it, and opened the gas pump valve to see if there was pressure in the tank and there wasnt. I just ordered the ECS in-line fuel pressure guage. and I'm wondering if the tune is supposed to be used with the stock DBC 3 bar fpr or the newer 4 bar fpr, tuner didnt specify anythingWell I'd go ahead and try the old throttle body. And yea knowing fuel pressure would help alot at this point.

Another thing I would say to is to restart the ECU Everytime before you start until it starts running correctly.

[QuattroBucc]

Well I'd go ahead and try the old throttle body. And yea knowing fuel pressure would help alot at this point.

Another thing I would say to is to restart the ECU Everytime before you start until it starts running correctly.

Yea Ill try the old throttlebody and see if that changes anything- but It does point to a vacuum leak because long term fuel trims climb up to 10% and then it starts idling much better, Why do you suggest restarting ecu every startup? I restart it with every change I make to see if the long term fuel trims climb up the same 10% and they always do

[B5carl]

Yea Ill try the old throttlebody and see if that changes anything- but It does point to a vacuum leak because long term fuel trims climb up to 10% and then it starts idling much better, Why do you suggest restarting ecu every startup? I restart it with every change I make to see if the long term fuel trims climb up the same 10% and they always doBecause that first start on a new trim will give you a lot of info on an underlying issue. What do you mean it climbs to 10%?

[QuattroBucc]

Because that first start on a new trim will give you a lot of info on an underlying issue. What do you mean it climbs to 10%?

I mean it gets up to 10% and stays there because the ecu is learning, long term and short term fuel trims are different, so basically ad idle its getting unmetered air so its adding 10% fuel try to maintain lambda 1 aka 14.7 afr

[B5carl]

I mean it gets up to 10% and stays there because the ecu is learning, long term and short term fuel trims are different, so basically ad idle its getting unmetered air so its adding 10% fuel try to maintain lambda 1 aka 14.7 afrSo on a cold start while it's still on a long trim it idles smoother and doesn't go over 10%?

[QuattroBucc]

So on a cold start while it's still on a long trim it idles smoother and doesn't go over 10%?

what do you mean? the 10% is the learned long trim. when I start it up it is already adding that 10% it has previously learned

[B5carl]

what do you mean? the 10% is the learned long trim. when I start it up it is already adding that 10% it has previously learnedI see what you mean, either way its not a smooth idle

[QuattroBucc]

I see what you mean, either way its not a smooth idle

its pretty smooth once the ecu has learned that it has to add 10% fuel to try to maintain perfect lambda at idle, the idles not really the problem anymore, driving it at part throttle is. It can learn to add 10% fuel overall, but with a vacuum leak or fuel pressure drop thats happening when I tip in the gas pedal that 10% isnt enough and it still goes insanely lean before coming back to rich, i think theres a weird vacuum leak somewhere that i can't find, so as I tip in the gas pedal the motor is also sucking in a ton of unmetered air and the AFR on my o2 sensor shows up to 18 afr ,because its not adding fuel for the unmetered air. infact it goes so lean it cant read anymore, then upstream o2 sensor sees that exhaust gases are extremely lean so it adds the max 25% short term fueling it can and goes pig rich to 10.0. Thats what makes the most sense, If it was a fuel pressure drop I don't think it would come back pig rich like that

[B5carl]

its pretty smooth once the ecu has learned that it has to add 10% fuel to try to maintain perfect lambda at idle, the idles not really the problem anymore, driving it at part throttle is. It can learn to add 10% fuel overall, but with a vacuum leak or fuel pressure drop thats happening when I tip in the gas pedal that 10% isnt enough and it still goes insanely lean before coming back to rich, i think theres a weird vacuum leak somewhere that i can't find, so as I tip in the gas pedal the motor is also sucking in a ton of unmetered air and the AFR on my o2 sensor shows up to 18 afr ,because its not adding fuel for the unmetered air. infact it goes so lean it cant read anymore, then upstream o2 sensor sees that exhaust gases are extremely lean so it adds the max 25% short term fueling it can and goes pig rich to 10.0. Thats what makes the most sense, If it was a fuel pressure drop I don't think it would come back pig rich like thatYea makes sense. Idk what else it could be maybe a bad ECU or wiring

[QuattroBucc]

Yea makes sense. Idk what else it could be maybe a bad ECU or wiring

Idk what wiring could be bad, I've quadruple checked the maf wiring and its all intact and its the only wiring that was modified besides the injectors Jetronic to UsCar Adapters- and injectors should be good they are flow matched bosch ev14 630cc from ringer racing , checked the coil wiring and that's good, tried complete diff set of coilpacks and nothing changed. Come to think of it I remember when I was first trying to get the car started there was a lot of air in the fuel system from having the fpr and injectors out of the rail for 2 weeks, so when i'd turn the key to power and the fuel system would prime it sounded just like a ton of air in there- it would start then die - start then die, until it seemed to get the air out and sounded like normal priming, but maybe there is still air in the fuel lines or something? The aem 340lph fuel pump itself is only a year old and I did a new fuel filter at that time

[Blazius]

@blazius do you know if an o2 sensor is really bad that it could be telling the car to adjust fueling completely wrong and make the afr bounce around constantly?? I have no codes for o2 sensors or anything else but I'm not too keen on just dishing out another $100 for a bosch o2 sensor if mine is working normal

Not really, if the sensor was bad you'd have a code thrown for sure there are many many checks in software, unless the dtc is coded out then it would not show in diagnostic software , its unlikely that is the case if you did not ask for it.


haven't tried the old throttle body yet, and i cant reflash it, i had to mail the ecu to the tuner and he flashed it and sent it back. Uhmmm I don't know if its completely capped, the line that goes into the evap solenoid coming from the fender well i capped off, I just tried the car with it uncapped and it didn't change anything. But that does make me think, as I Tip in the gas afr goes up to 17 18 then comes back down, so it could be losing fuel pressure at the tip in of the gas pedal, or vacuum leak. Would opening up my gas cap to relieve pressure work as as test with that? Nope- just tried it, and opened the gas pump valve to see if there was pressure in the tank and there wasnt. I just ordered the ECS in-line fuel pressure guage. and I'm wondering if the tune is supposed to be used with the stock DBC 3 bar fpr or the newer 4 bar fpr, tuner didnt specify anything

Longitudinal a4 b5's always run 4 bar FPR from factory , never change it , never unplug it from manifold pressure. The car will be and should be tuned to it.

Group 32 should have 2 ltfts, I am not sure if that is the case on the dbc's but first box is idle addtivie ltft second is partial multiplicative. How are they looking?

[QuattroBucc]

Not really, if the sensor was bad you'd have a code thrown for sure there are many many checks in software, unless the dtc is coded out then it would not show in diagnostic software , its unlikely that is the case if you did not ask for it.



Longitudinal a4 b5's always run 4 bar FPR from factory , never change it , never unplug it from manifold pressure. The car will be and should be tuned to it.

Group 32 should have 2 ltfts, I am not sure if that is the case on the dbc's but first box is idle addtivie ltft second is partial multiplicative. How are they looking?

DBC are the rare exception that had 3 bar fpr in there, ill ask the tuner if i was supposed to upgrade to the 4bar

[Rmr1499]

Why not upgrade to the wideband setup [emoji28]


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[Blazius]

I really don't think its the tune, if it works flawless for everybody else why would it be bad for my car? I think its something hardware related like the MAF got fried when getting a constant 5v on the signal wire, or wastegate is leaking. @blazius do you know if an o2 sensor is really bad that it could be telling the car to adjust fueling completely wrong and make the afr bounce around constantly?? I have no codes for o2 sensors or anything else but I'm not too keen on just dishing out another $100 for a bosch o2 sensor if mine is working normal


DBC are the rare exception that had 3 bar fpr in there, ill ask the tuner if i was supposed to upgrade to the 4bar

No, im 99% sure and double checked even before posting. It's a 4 bar FPR if you got a 3bar someone unknowingly put it in there.


Wideband setup would require conversion to dbw me7, its a bit of work but worth it IMO. Much easier to get an oem car though, but they seem to be getting rarer even over there.

[QuattroBucc]

No, im 99% sure and double checked even before posting. It's a 4 bar FPR if you got a 3bar someone unknowingly put it in there.


Wideband setup would require conversion to dbw me7, its a bit of work but worth it IMO. Much easier to get an oem car though, but they seem to be getting rarer even over there.

Uhhh even my tuner just asked If I'm using the stock 3 bar. I'm pretty sure there the aeb 150hp models had 3 bar fpr in there for 2 years. But if thats not actually the case and its supposed to be 4 bar that could be a big issue lol

[B5carl]

Another thing I'm thinking about is what happens to the AFR after you bip the throttle at idle or below 25%? After it learned the 10% does the AFR float around 14.7?

Correct me if I'm wrong but the narrow band only has 3 values for correcting fuel (Lean - stoichiometric - Rich) right? Where as narrow band has 12 corresponding with voltage

It's confusing because if it's tuned you really shouldn't have to adjust anything unless the tuner says to. Having the wideband is really only good for tuning, in this case we are assuming that it's not a tune issue. The ProMAF should be adding more precision to monitoring air flow idk why the fueling isn't right. I'm also guessing at this point that your positive that you don't have a vaccum leak

[QuattroBucc]

Another thing I'm thinking about is what happens to the AFR after you bip the throttle at idle or below 25%? After it learned the 10% does the AFR float around 14.7?

Correct me if I'm wrong but the narrow band only has 3 values for correcting fuel (Lean - stoichiometric - Rich) right? Where as narrow band has 12 corresponding with voltage

It's confusing because if it's tuned you really shouldn't have to adjust anything unless the tuner says to. Having the wideband is really only good for tuning, in this case we are assuming that it's not a tune issue. The ProMAF should be adding more precision to monitoring air flow idk why the fueling isn't right. I'm also guessing at this point that your positive that you don't have a vaccum leak

I tried to explain earlier but its hard to get across without video, at this point i should just make a video and put it on youtube for yall to check out. when I blip the throttle from idle afr goes from 14.7ish up to 17/18- super lean. Im pretty sure you're correct about narrowband only being able to adjust between reading those 3 values. Yeah having the wideband is just for peace of mind doing a WOT pull you can let out if you start to see anything lean. I'm pretty sure but I'll keep testing for leaks, and if i do have a leak its not that big because vacuum is still at -17

[B5carl]

I tried to explain earlier but its hard to get across without video, at this point i should just make a video and put it on youtube for yall to check out. when I blip the throttle from idle afr goes from 14.7ish up to 17/18- super lean. Im pretty sure you're correct about narrowband only being able to adjust between reading those 3 values. Yeah having the wideband is just for peace of mind doing a WOT pull you can let out if you start to see anything lean. I'm pretty sure but I'll keep testing for leaks, and if i do have a leak its not that big because vacuum is still at -17Yea man idk you can probably get a new o2 install it real quick to see if it makes a difference and just clean it off and return it if it doesn't

[Blazius]

Uhhh even my tuner just asked If I'm using the stock 3 bar. I'm pretty sure there the aeb 150hp models had 3 bar fpr in there for 2 years. But if thats not actually the case and its supposed to be 4 bar that could be a big issue lol

Just checked again specifically US market 1996-2001 B5's had one FPR 078133534C and it is a 4bar. Transverse cars run 3 bar FPR.

https://www.ecstuning.com/b-bosch-parts/fuel-pressure-regulator/078133534c~bos/

[4ringstg3]

Have you checked you coil pack harness to see if there are any breaks in it?
I’m guessing you did an ICM delete.
If you did check that as well

I bought one from 034 (a while back) and it was wired wrong


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[QuattroBucc]

Yea man idk you can probably get a new o2 install it real quick to see if it makes a difference and just clean it off and return it if it doesn't

idk if i could get it clean enough to actually return but thats an idea

- - - Updated - - -


Just checked again specifically US market 1996-2001 B5's had one FPR 078133534C and it is a 4bar. Transverse cars run 3 bar FPR.

https://www.ecstuning.com/b-bosch-parts/fuel-pressure-regulator/078133534c~bos/

ah okay got it, then just my tune specific the tuner wants the 3 bar in there.

[QuattroBucc]

Have you checked you coil pack harness to see if there are any breaks in it?
I’m guessing you did an ICM delete.
If you did check that as well

I bought one from 034 (a while back) and it was wired wrong


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I have checked, and yes I did an ICM delete but the icm delete and coilpack conversion has been on the car for 2 years and doesn't have coil misfire problems.

[B5carl]

idk if i could get it clean enough to actually return but thats an idea

- - - Updated - - -



ah okay got it, then just my tune specific the tuner wants the 3 bar in there.Wtf yea you definitely can they don't check it at AutoZone or O'Riley. If they do as long as it's visually clean they'll pass it and the box isn't torn.

[QuattroBucc]

Wtf yea you definitely can they don't check it at AutoZone or O'Riley. If they do as long as it's visually clean they'll pass it and the box isn't torn.

I'm gonna try that when I get in the fuel pressure guage which I think fuel pressure might be the issue actually, I can hear this fast on/off hissing noise in the feed line going into the bottom of the FPR. And when I prime the fuel system turning key it sounds like its compressing air in the fuel rail, no matter how many times i cycle it. I filmed the hissing sound if you listen closely you can hear it go on/off super fast. What would cause this??? i opened up the fuel tank and checked the pump wires to see if they were frayed or anything and they are all good, maybe the aem pump died within 1 year and 10k miles lol, fuel filter was replaced at same time of the new pump. listen to this video i filmed https://www.youtube.com/watch?v=_L2ajARTVXI and the hissing is not a vacuum leak, its boost tested up to 25 psi. FPR is brand new. Whats causing this on/off erratic fuel flow into the FPR??? just based on how the fuel flow sounds into the FPR it seems like the fuel pressure guage coming will be jumping around a ton, is this the fuel pump/filter have gone bad?

[B5carl]

Who knows. Did you ever get that ecs inline fuel pressure gauge?

[QuattroBucc]

Who knows. Did you ever get that ecs inline fuel pressure gauge?

shipping got delayed for whatever reason, supposed to show up today

[Rmr1499]

shipping got delayed for whatever reason, supposed to show up today

Because it’s ECS tuning everything is always delayed or messed up


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[QuattroBucc]

Because it’s ECS tuning everything is always delayed or messed up


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lol agreed ECS is the last place ill order from but sometimes they're the only place with stuff "in stock" fcp euro is my go-to.

SO GUYS, put the FPR on and holy shit it was horrible, Idling its literally 10-15 psi of fuel pressure so I guess im ordering a walbro 255lph and might as well put in a new fuel filter aswell. Really didn't think fuel would be the issue since I have an AEM 340lph in the tank thats ONLY a year and a half old. Either theres a major restriction in the line somewhere or fuel pump took a shit, Usually when fuel pumps have failed for me in the past its more of a major fail rather than just low fuel pressure

[QuattroBucc]

Alright so I feel like a dumbass i had the fuel pressure guage on the return line because I thought the feed goes into the regulator and thats how it regulates pressure but I soon discovered the regulator is at the end of the rail and bleeds off pressure instead. Switched where the fuel pressure guage was and now it shows normal 35psi under vacuum and 45 psi with vacuum disconnected which is what the 3 bar is rated for. Fuel pressure doesn't really drop when I rev the car either so Unfortunately what I thought was gonna be the final end of the road to finding this cars issue just became a longer road.

B5Carl I put in a brand new bosch o2 sensor and it didn't change anything, the car still idles and revs at the same afr's it was before so my old o2 sensor must of been fine.

Well I'm at the end of my rope and I think I'm gonna have to get it towed to the nearest united motorsport dealer which is an hour and a half away for them to figure out, Im pretty sure after dialing in that its not the o2 sensor, fuel pump/pressure, not a vacuum leak, and everything else we've gone over that the problem has to be either the Maf itself, the tune, or is it possibly a bad ecu??

I took a video showing how afr goes to 17:1 when i rev it and hold, and how vagcom tries to compensate and add over 20% fueling https://www.youtube.com/watch?v=7R659rN9yho if anyone cares to check it out

[B5carl]

Alright so I feel like a dumbass i had the fuel pressure guage on the return line because I thought the feed goes into the regulator and thats how it regulates pressure but I soon discovered the regulator is at the end of the rail and bleeds off pressure instead. Switched where the fuel pressure guage was and now it shows normal 35psi under vacuum and 45 psi with vacuum disconnected which is what the 3 bar is rated for. Fuel pressure doesn't really drop when I rev the car either so Unfortunately what I thought was gonna be the final end of the road to finding this cars issue just became a longer road.

B5Carl I put in a brand new bosch o2 sensor and it didn't change anything, the car still idles and revs at the same afr's it was before so my old o2 sensor must of been fine.

Well I'm at the end of my rope and I think I'm gonna have to get it towed to the nearest united motorsport dealer which is an hour and a half away for them to figure out, Im pretty sure after dialing in that its not the o2 sensor, fuel pump/pressure, not a vacuum leak, and everything else we've gone over that the problem has to be either the Maf itself, the tune, or is it possibly a bad ecu??

I took a video showing how afr goes to 17:1 when i rev it and hold, and how vagcom tries to compensate and add over 20% fueling https://www.youtube.com/watch?v=7R659rN9yho if anyone cares to check it outYea I had a feeling the o2 sensor wasn't faulty so I guess the last resort is to bring it to a tuner because I have no idea at this point.

[4ringstg3]

I had a buddy who had an intermittent misfire. We changed out the ignition starter switch and it seems to go away 🤷*♂️


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[Blazius]

Did you get a 3 bar FPR ... ?

[QuattroBucc]

Did you get a 3 bar FPR ... ?

yes that's what the tuner asked for - for this tune, he wants it 3 bar instead of 4 bar I asked him

[QuattroBucc]

Latest Update, my tuner is incompetent and there was nothing wrong with my car. The tune is setup specifically for deka siemens injectors I guess. From the start I told him I had bosch ev14 630cc from ringer racing and he didn't say they would'nt work. Until just 1 week ago he goes "wait what you have bosch injectors why would you run those when you know they are not siemens" and im like dude "I told you from the very start I had bosch ev14 630ccs" and he goes "well thats just part of your problem but not all of it"..... except it was my WHOLE problem. So I just got my hand on some Deka siemens 630ccs and guess what, the car runs just fine now with stable AFR and long term fuel trim around -3%, this is very frustrating to find out after 3 months of having an undriveable car and changing everything on it, o2 sensors, new promaf, throttlebody, etc that none of that was the issue, it was just that my tuner is incompetent and didn't tell me to run Deka siemens, and didn't tell me the tune wouldn't work with other brands cuz injector dead times. even their website just says 630cc injectors not specifically deka. Atleast my car runs now but damn I want to slap the dude for wasting so much of my time. But thank you so much for everyones help even though I didn't really need to do any of this work besides fix my boost leak

[B5carl]

Latest Update, my tuner is incompetent and there was nothing wrong with my car. The tune is setup specifically for deka siemens injectors I guess. From the start I told him I had bosch ev14 630cc from ringer racing and he didn't say they would'nt work. Until just 1 week ago he goes "wait what you have bosch injectors why would you run those when you know they are not siemens" and im like dude "I told you from the very start I had bosch ev14 630ccs" and he goes "well thats just part of your problem but not all of it"..... except it was my WHOLE problem. So I just got my hand on some Deka siemens 630ccs and guess what, the car runs just fine now with stable AFR and long term fuel trim around -3%, this is very frustrating to find out after 3 months of having an undriveable car and changing everything on it, o2 sensors, new promaf, throttlebody, etc that none of that was the issue, it was just that my tuner is incompetent and didn't tell me to run Deka siemens, and didn't tell me the tune wouldn't work with other brands cuz injector dead times. even their website just says 630cc injectors not specifically deka. Atleast my car runs now but damn I want to slap the dude for wasting so much of my time. But thank you so much for everyones help even though I didn't really need to do any of this work besides fix my boost leakWow, so injectors this whole time. At least you have the IE cams too so you don't have to worry about breaking the gear on the SPA.

[B5carl]

How does it drive? Does it feel like it has the power that they advertised? I know off the shelf tunes aren't perfect but I'd like to know how yours is.

[QuattroBucc]

How does it drive? Does it feel like it has the power that they advertised? I know off the shelf tunes aren't perfect but I'd like to know how yours is.

Drives pretty great now, the load at idle feels great like you don't have to use any gas to get rolling like 5mph just let the clutch out smoothly. I can't really comment on the power cuz all i've seen so far is 6 psi because its just on wastegate pressure right now and that was 3/4 throttle. Since the bottom end is still freshly built and a brand new clutch in there I'm not gonna fully load her up for probably 1-200 miles to break her in then I'll do an oil change and install my GFB Atomic boost controller and start dialing in the psi I want. Right now the head on it is the stock one with sodium filled exhaust valves so i gotta keep boost kinda low maybe, some people get away with them at 400whp but some break their exhaust valves and toast their engine. Remember the head i built made low compression so I gotta fix that before i re-install that head with the IE cams.

[B5carl]

Drives pretty great now, the load at idle feels great like you don't have to use any gas to get rolling like 5mph just let the clutch out smoothly. I can't really comment on the power cuz all i've seen so far is 6 psi because its just on wastegate pressure right now and that was 3/4 throttle. Since the bottom end is still freshly built and a brand new clutch in there I'm not gonna fully load her up for probably 1-200 miles to break her in then I'll do an oil change and install my GFB Atomic boost controller and start dialing in the psi I want. Right now the head on it is the stock one with sodium filled exhaust valves so i gotta keep boost kinda low maybe, some people get away with them at 400whp but some break their exhaust valves and toast their engine. Remember the head i built made low compression so I gotta fix that before i re-install that head with the IE cams.Nice man good to hear all that got resolved. Keep us updated with progress on the head work and compression test. Also want to see how the car runs with the IECVA2'S

[Blazius]

Well how many times Ive mentioned the hardware needs to be matched to the tune :)
Dekas are almost 100cc larger , without lamba control the car wouldnt even run probably.

Anyway the injection time in motroniv is load x injector scaling (load/ms of opening) + dead time basically. Dead times will throw off idle most and low loads because sometimes the deadtime is larger than the opening time, injector scaling needs to be on point all times.

As for rings you actually supposed to drive it hard, its chamber pressure gases that push the rings against the bore and crosshatching which is like a file. Look it up :)

[QuattroBucc]

Well how many times Ive mentioned the hardware needs to be matched to the tune :)
Dekas are almost 100cc larger , without lamba control the car wouldnt even run probably.

Anyway the injection time in motroniv is load x injector scaling (load/ms of opening) + dead time basically. Dead times will throw off idle most and low loads because sometimes the deadtime is larger than the opening time, injector scaling needs to be on point all times.

As for rings you actually supposed to drive it hard, its chamber pressure gases that push the rings against the bore and crosshatching which is like a file. Look it up :)

Yeah I wish my tuner told me the bosch weren't the correct ones when i told him what I had, Would've saved me a lot of time and hassle of part swapping. So I should drive it hard to break it in- even with a new clutch? its the RA4 240mm Clutch Conversion Kit - Stage 2. Turbo is the VSR Next Gen 58/55 DBB which flows a claimed 66lbs/min, what do you think I can safely turn my boost up to with the stock head with sodium filled valves?

[Blazius]

Just run on actuator pressure, 0% wgdc

[QuattroBucc]

Just run on actuator pressure, 0% wgdc

just to break in the rings? or is that all the sodium filled valves can handle lol? i think WG pressure is 6psi because thats when it was opening up

[B5carl]

So your only expecting to make 400whp? The GTX3076R gen2 is 67lbs/min and it maxes out at 750hp on a bigger engine. So you could make 500-600whp?? The IE cams when tuned in also proven to give you 60+ hp if you got the IECVA2'S

[QuattroBucc]

So your only expecting to make 400whp? The GTX3076R gen2 is 67lbs/min and it maxes out at 750hp on a bigger engine. So you could make 500-600whp?? The IE cams when tuned in also proven to give you 60+ hp if you got the IECVA2'S

I just read the gtx3076r gen 2 which is what my turbo is a copy of, that they don't actually flow the claimed 66lbs because the compressor wheel is too small and gets super out of its efficiency range but maybe not, yeah I wasn't going for 500-600whp i was gonna keep the boost lower to make around 450-475whp, but even with that size turbo it is making positive pressure at 3000 rpm because I have a full twinscroll setup. I still have the stock pistons in there, i don't think they can survive at 500-600whp but maybe eventually ill build out my car more.

Also a huge factor to keeping the power down is the stock trans, mine has 210k miles on it right now and everybody blows 3rd gear out around 350whp shifting hard, you can get a clutch delay valve to help the shock on the transmission during hard shifts, it basically always slips the clutch during shifts a little so the torque gets loaded onto the trans not all at once. Only way around that is drop in an o1e from the s4 with taller gear ratios which might not be thaaaat bad, I was considering it before but now actually driving my build the lack of torque down low probably wouldn't feel very good around town, And especially when I drop the built head with the IE cams i will lose even more low end torque so probably not a good trans for a built cammed motor, maybe if it was stroked and had more torque, people that stroke out to 2.1 say it feels like the torque of a v6 so way better around town. There is transmission swaps to more current 6 speed trans like the o1x to keep good ratios for the 4 cylinder but that is a lot of work and you lose your speedo and have to run a digital speedo.

[B5carl]

Yea I don't plan on doing 01E until I see what it's really like breaking the 01A. Im gonna contact JHM and see if they can get the cryo heat treating done on my spare 01A and see how it holds up and yea a flow control valve is always good with high performance fluid.

2.0L is what I'm doing for low end, the 2.1 with the TDI crank is also another option I was considering but I already bought the 92.8mm JE Pistons for the 2008cc kit. I tried to sell my IE modified FSI crank for some quick cash and thought about getting the billet crank but I guess I'll keep this one.

Alot of people have done the 01E and not to many complain so if you can get that S4 for $800 then I would just do the swap.

[QuattroBucc]

Yea I don't plan on doing 01E until I see what it's really like breaking the 01A. Im gonna contact JHM and see if they can get the cryo heat treating done on my spare 01A and see how it holds up and yea a flow control valve is always good with high performance fluid.

2.0L is what I'm doing for low end, the 2.1 with the TDI crank is also another option I'm considering but I already bought the 92.8mm JE Pistons for the 2008cc kit.

Alot of people have done the 01E and not to many complain so if you can get that S4 for $800 then I would just do the swap

Breaking the o1a is just a matter of time, some people say they weren't even power shifting it and it blows, one guy said he'd gone through 5 trannys in 1 year at the 400whp mark lol before he went O1E. I wonder how much cryo treating actually strengthens the gears/input shaft.
Do you have info on other kind of trans that got cryo treated and it increased the torque it can handle by a lot?

Yeah i need to grab that car asap if the guy still has it, i could even just sell all the parts of it if i didn't do the swap. Just need to find a way to get it towed down. I wonder if AAA will tow a nonrunning car i just bought, my brother did it before with a 71 datsun 240z but i've heard some AAA drivers refuse to tow non running cars that people buy.

[B5carl]

Breaking the o1a is just a matter of time, some people say they weren't even power shifting it and it blows, one guy said he'd gone through 5 trannys in 1 year at the 400whp mark lol before he went O1E. I wonder how much cryo treating actually strengthens the gears/input shaft.
Do you have info on other kind of trans that got cryo treated and it increased the torque it can handle by a lot?

Yeah i need to grab that car asap if the guy still has it, i could even just sell all the parts of it if i didn't do the swap. Just need to find a way to get it towed down. I wonder if AAA will tow a nonrunning car i just bought, my brother did it before with a 71 datsun 240z but i've heard some AAA drivers refuse to tow non running cars that people buy.Idk I heard the guy Mike hood at ringer racing can probably give you a lot of info on his experience with the 01A. You can probably email him and ask what he thinks. I think he was the guy that was talking to JHM a while ago about doing cryo heat treating services if enough people were interested but that is definitely out of the question as of 2021. The car was hot like 10 years ago unfortunately

I really have no choice, I have 2 of them so I can test one and of it breaks then I have another one to sit on while I decide what to do. Not trying to spend over $1k on a drivetrain swap I'm still trying to get all my other parts together. I'd have to get a blown S4 like your doing it seems like a better deal to be honest unless someone is willing to part one out for cheap.

[QuattroBucc]

Idk I heard the guy Mike hood at ringer racing can probably give you a lot of info on his experience with the 01A. You can probably email him and ask what he thinks. I think he was the guy that was talking to JHM a while ago about doing cryo heat treating services if enough people were interested but that is definitely out of the question as of 2021. The car was hot like 10 years ago unfortunately

I really have no choice, I have 2 of them so I can test one and of it breaks then I have another one to sit on while I decide what to do. Not trying to spend over $1k on a drivetrain swap I'm still trying to get all my other parts together. I'd have to get a blown S4 like your doing it seems like a better deal to be honest unless someone is willing to part one out for cheap.

Ill probably ask him, Hes been good to do business with, fixed the wrong injectors i got sent no hassle. I can't say the same for Fred @ united motorsports, what a douche honestly. He was getting mad at me saying i have to take my car to a shop etc that i must of built it wrong, when this whole time it was his fault that he never told me it requires dekas, even when i told him i had bosch ev14 he didn't say they wont work, and now he refuses i ever told him that i had bosch lmao. He is also refusing to take my return of the 2nd promaf I ordered even when I never took it out of the box, he said on the phone hed take the return if it was never installed. So, dont go with united motorsports, if anyone's considering, just don't, its been a bad experience overall from the start they never even included wiring instructions for the promaf and I wish I had stayed with eurodyne Maestro because that I can have customly tuned by someone atleast and when I make changes to my car update them in the tune.

[B5carl]

Yea I agree hopefully the guy at motoza sets me up with a good tune for the ID1050x

[Blazius]

Cryo treating, clutch delay all really waste of money ,big hp numbers on quattro there is one solution only, that is the 01E ,the b7's trans are weaker even though they got better syncros.

Why would anyone use dekas in 2021 is beyond me (and dropping fpr to 3bar lol).. oh wait I know, its because their tune is years old and they arent even doing anything on these cars anymore due to profitability I guess.


400 is what you can run on stock exhaust valves, but it all depends on tune and your egt's, about the same on 01a depending on how you drive it, obviously dont launch it.

[QuattroBucc]

Dang those are some big injectors, I doubt you'd need more than 80lb injectors for 500whp, are you going that big to run e85?

[QuattroBucc]

Cryo treating, clutch delay all really waste of money ,big hp numbers on quattro there is one solution only, that is the 01E ,the b7's trans are weaker even though they got better syncros.

Why would anyone use dekas in 2021 is beyond me (and dropping fpr to 3bar lol).. oh wait I know, its because their tune is years old and they arent even doing anything on these cars anymore due to profitability I guess.


400 is what you can run on stock exhaust valves, but it all depends on tune and your egt's, about the same on 01a depending on how you drive it, obviously dont launch it.

I know dekas are shitty, just seeing the spray pattern of deka vs bosch ev14 in flow tests I would think the bosch would make more power due to a better swirl in the combustion chamber. Do you think I should just run the 4 bar for better atomizing of fuel and the ecu can correct trims? or is that a bad way to go.

[Blazius]

If the tune is for 3 bar, you cant run 4 bar fpr without changes to it, because increasing the fuel pressure also increases injector effective capacity along things like atomization. Cant go different injector or anything in the fuel system size except for pump wihtout changes to the tune, but its not needed, I am just saying its bad way to build a car these days, 7-8 years ago , sure it was fine until people found out the 1.8t20v does not like dekas.

[B5carl]

I was under the impression that I needed 1000cc which I'm sure I do for 500 with water methanol and 93 also 2.0L

[QuattroBucc]

I was under the impression that I needed 1000cc which I'm sure I do for 500 with water methanol and 93 also 2.0L

Maybe, seems a bit overkill if you can get 450whp on 630ccs . Wouldn't you need even less injector if you're also spraying water meth?

[B5carl]

Maybe, seems a bit overkill if you can get 450whp on 630ccs . Wouldn't you need even less injector if you're also spraying water meth?I thought the meth evaporated into dense air which needs more fuel but idk honestly I'm going by other 1.8t and Evo 4g63 guys

[QuattroBucc]

I thought the meth evaporated into dense air which needs more fuel but idk honestly I'm going by other 1.8t and Evo 4g63 guys

Found this "The water/methanol injection enabled us to run the same air/fuel ratios as a pump gas tune, but with less fuel added to the map of our engine management software. Tuning with water/methanol injection, we typically ended up with the same air/fuel ratios common to pump-fuel tunes, but with less fuel needed, and the benefits of increased knock resistance. " so you do need less fuel when you add in water meth, thats from https://www.motortrend.com/how-to/impp-1101-water-methanol-injection/

[B5carl]

Found this "The water/methanol injection enabled us to run the same air/fuel ratios as a pump gas tune, but with less fuel added to the map of our engine management software. Tuning with water/methanol injection, we typically ended up with the same air/fuel ratios common to pump-fuel tunes, but with less fuel needed, and the benefits of increased knock resistance. " so you do need less fuel when you add in water meth, thats from https://www.motortrend.com/how-to/impp-1101-water-methanol-injection/Oo ok I didn't really do research on a meth kit yet just skimming

[QuattroBucc]

Oo ok I didn't really do research on a meth kit yet just skimming

yea so you probably don't need 1050s lol that's probably 650whp capable, unless you just want them but it might affect Idle being that big of an injector

[QuattroBucc]

Cryo treating, clutch delay all really waste of money ,big hp numbers on quattro there is one solution only, that is the 01E ,the b7's trans are weaker even though they got better syncros.

Why would anyone use dekas in 2021 is beyond me (and dropping fpr to 3bar lol).. oh wait I know, its because their tune is years old and they arent even doing anything on these cars anymore due to profitability I guess.


400 is what you can run on stock exhaust valves, but it all depends on tune and your egt's, about the same on 01a depending on how you drive it, obviously dont launch it.

400 wheel? or crank for exhaust valves?

[Blazius]

crank , but it just a number, its hard to gauge, on E85 you would obviously make more power because lower egts on stock valves it all just depends on egts, dumping AFR to cool the combustion loses you power but allows you to run on stock hardware, when in comparison on same setup with proper AFR you would make 10 more hp , you get what I mean? Just get supertech, relatively cheap and good, and you will be fine. Stock pistons 20mm ones can handle 600+, if you arent knocking to hell.

[QuattroBucc]

crank , but it just a number, its hard to gauge, on E85 you would obviously make more power because lower egts on stock valves it all just depends on egts, dumping AFR to cool the combustion loses you power but allows you to run on stock hardware, when in comparison on same setup with proper AFR you would make 10 more hp , you get what I mean? Just get supertech, relatively cheap and good, and you will be fine. Stock pistons 20mm ones can handle 600+, if you arent knocking to hell.

Ah yeah I getcha, more fuel is safer but lose a bit of power. my built aeb head has inconel exhaust valves in it and stock intakes, but Its off the car right now because it made low compression, before install i had the machine shop who decked it check the valve guides clearance and they were all in spec but now with the assembled head off the car the intake valves have some play to them so that is probably why but idk how that happened, so they are not sealing properly. Gotta have the machine shop press in new guides and might as well have them assemble it and I might as well get a 3 angle valve job while im there since OEM is just a single 45 degree seat cut, probably gain 15cmf just doing the 3 angle valve job.

What psi do you think i can get away with while my head is at the shop because its probably going to take them 3 months to get to it, car didn't feel that fast on 6 psi so I can definitely turn it up some safely

[Blazius]

I dont know, pressure is not all. 10-15 maybe, but what do you mean "turn" it up. You dont turn your boost up, the tuner sets it.

[QuattroBucc]

I dont know, pressure is not all. 10-15 maybe, but what do you mean "turn" it up. You dont turn your boost up, the tuner sets it.

maybe my n75 is not working but my tuner said to increase boost id have to use a boost controller on top of the n75

[B5carl]

That's what I was saying I was so confused when you said you could change your boost settings. I was under the impression that there's only 1 boost settings per tune. I honestly don't understand how the GFB controller works

I understand that you can turn it down but there's a peak number

[QuattroBucc]

That's what I was saying I was so confused when you said you could change your boost settings. I was under the impression that there's only 1 boost settings per tune. I honestly don't understand how the GFB controller works

I understand that you can turn it down but there's a peak number

with my 44mm external gate i control the boost levels i run by the spring pressure in the gate and whatever n75 does, to increase it you run a boost controller in between the gate and the n75 which bleeds off some air so that the gate stays closed, like if your gate is 10 psi and then you bleed off 50% with a manual boost controller in between ur boost reference and wastegate you'll get 15 psi or so because now the pressure thats opening the gate is being bled off. pretty sure there is no limit to how much you can raise your boost this way by increasing spring pressure and using boost controllers to bleed of pressure to the wg spring (besides turbine running out of efficiency, then you can get a larger hotside housing but there is still a limit, thats what the A.R. of the hotside does, like .63 will spool fast because it has a lot of back pressure but then at high rpm the back pressure is so high you can only get so high of boost levels, so to get higher boost levels you run a larger housing like a 1.01-it will spool slower but have way less back pressure and be more efficient and have higher boost potential and you actually make more hp per same level of boost because of the decreased backpressure your engine breathes better, even on my 04 GLI i have AEM truboost i can change my boost settings on a fly and its not changing the tune.

As long as the fuel map is there all the way to the max g/s the maf can read why would the tune need to be set to a specific psi value? That would be if you're only using n75 and no electronic/manual boost controller, but most people run no n75 and use boost controllers, like a 3 or 4 port boost solenoid is way more efficient than the n75 when fine tuned

[B5carl]

Oo I see

[QuattroBucc]

were you planning on only using the stock n75 for boost control? its pretty shitty and not near as quick as a 3 port solenoid

[B5carl]

were you planning on only using the stock n75 for boost control? its pretty shitty and not near as quick as a 3 port solenoidI was thinking about getting the MAC 3 port but I haven't really looked into it yet. Basically you can just wire it up to the stock n75 plug right? So the n75 is either on or off? I'm gonna do some research on it eventually.

[QuattroBucc]

I was thinking about getting the MAC 3 port but I haven't really looked into it yet. Basically you can just wire it up to the stock n75 plug right? So the n75 is either on or off? I'm gonna do some research on it eventually.

you can run it in between ur wg and n75 just like any boost controller or you can take out the n75 of the equation and remove it from the tip but leave it plugged in and run only the mac 3 port, my GLI has a mac 3 port with the AEM truboost guage and its awesome, just through the guage i can set 3 diff boost maps that i want because you're just changing the duty cycle of the WG its like having diff tunes you can swap around , the gain and everything so you could have like a 15 psi map a 25 psi map and a chauffeur mode with like 5 psi lets say with super slow onset of boost, it even offers scramble setting so if you wire up a button you can engage scramble mid pull to a higher boost setting and go from lets say 20 psi to 25 psi, and even set a boost spike limit with the guage id highly reccomend it, i think im gonna swap it from my GLI into my b5

[B5carl]

you can run it in between ur wg and n75 just like any boost controller or you can take out the n75 of the equation and remove it from the tip but leave it plugged in and run only the mac 3 port, my GLI has a mac 3 port with the AEM truboost guage and its awesome, just through the guage i can set 3 diff boost maps that i want because you're just changing the duty cycle of the WG its like having diff tunes you can swap around , the gain and everything so you could have like a 15 psi map a 25 psi map and a chauffeur mode with like 5 psi lets say with super slow onset of boost, it even offers scramble setting so if you wire up a button you can engage scramble mid pull to a higher boost setting and go from lets say 20 psi to 25 psi, and even set a boost spike limit with the guage id highly reccomend it, i think im gonna swap it from my GLI into my b5Definitely gonna run it then I didn't think the n75 was that bad but never really looked into upgrading it

[B5carl]

Im actually looking to get the CANchecked MFD28 and it also has a boost control option. Setting it up is a little bit more involved because you need some external circuit hardware that they sell but looking to experiment with it

[QuattroBucc]

Im actually looking to get the CANchecked MFD28 and it also has a boost control option. Setting it up is a little bit more involved because you need some external circuit hardware that they sell but looking to experiment with it

are you going standalone or can you make it work with the motronic ? whats the point of getting it if still stock ecu? you just don't want guages? just 1 screen like a cobb access port

[B5carl]

are you going standalone or can you make it work with the motronic ? whats the point of getting it if still stock ecu? you just don't want guages? just 1 screen like a cobb access portStock ECU and yea I'm gonna have 3 guages and then I'll be able to see everything else on the MFD. Have you seen it? Probably one of the best mod for the car once it's built. Gonna start a build thread this spring so I'll keep you guys updated about how it goes.

[B5carl]

Basically I have to hook it up to something that can detect boost pressure and control it like your truboost controller, in my case the MFD28 so until then I have to use the N75 until I learn how to use it.

Even after I install it I think I still have to tune it in right? Everything online is saying that you can't just delete the stock n75 and hook it up

[QuattroBucc]

Basically I have to hook it up to something that can detect boost pressure and control it like your truboost controller, in my case the MFD28 so until then I have to use the N75 until I learn how to use it.

Even after I install it I think I still have to tune it in right? Everything online is saying that you can't just delete the stock n75 and hook it up

yea youd hook it up to your WG nipple so it controls the WG, as far as I know you can take the n75 out but leave it plugged in, and then use ur version of boost control, the n75 is just a boost controller controlled through the ecu, but it is pretty bad and slow responding, makjing your MFD28 your version of boost control its not through the ecu anymore but through ur MFD28 directly to the WG to control it, you could make the boost onset slow like a n75 or damn near instantaneous to max spool once the turbo lights up but thats super jerky so you want quick onset but not too quick and fine tuning the part throttle boost response, like taking out n75 and running just a manual boost controller is usually very spiky like you get all your boost at once when the turbo spools up, rather than with a n75 it "slowly" ramps up. stock n75 is good for super smooth part throttle low boost, with cheaper controllers boost can come in a bit hard sometimes but with the truboost or your MFD28 you should be able to fine tune it to be better than a n75 by far

[Blazius]

I dont recommend all that bs, just run it off the n75 and have a proper tune everything else is cutting corners. A well tuned car never spikes apart from initial overshoot(1psi) which is the nature of PID's. N75 is the only way, all depends on the tuner.

[B5carl]

I don't see why hooking it up directly to the MFD won't work. If the truboost worked without tuning then it should work

What I'm trying to say is the response time of the new controller will be different as you were saying I just don't know how the tune will compensate. And as you were saying you can control the onset of how quickly it will allow it to spool.

@Quattrobuck did you delete your old n75 out or was it plugged in? And you had to make sure it didn't go over the max boost that the tune allowed right? That's what I'm trying to get at. I'm sure it can relearn the new trim for a quicker solenoid but there's definitely a max for what the ecu will correct if the controller is independent from the ECU

[QuattroBucc]

I don't see why hooking it up directly to the MFD won't work. If the truboost worked without tuning then it should work

What I'm trying to say is the response time of the new controller will be different as you were saying I just don't know how the tune will compensate. And as you were saying you can control the onset of how quickly it will allow it to spool.

@Quattrobuck did you delete your old n75 out or was it plugged in? And you had to make sure it didn't go over the max boost that the tune allowed right? That's what I'm trying to get at. I'm sure it can relearn the new trim for a quicker solenoid but there's definitely a max for what the ecu will correct if the controller is independent from the ECU

i think the ecu is quick enough to compensate fuel, my gli is k04 if i go from cruising to floored i can go from -20 vacuum to 22 psi like less than a second and it doesn't buck or anything i think modern ecu is pretty fast with the map sensor. yeah controlling how fast it can spool is easy, the n75 already does that by opening the wastegate a lot so boost comes in tapered, its limiting the flow to the turbine, so with a 3 port mac valve or MFD whatever you are doing the same thing, changing the rate that the wastegate opens, keeping it shut all the time would make the turbo make full psi at all times. Also with the truboost you can tune boost by gear which is extremely nice so you're not just spinning in 1st and 2nd since my gli is FWD. on the GLI the n75 is just plugged in but not in the TIP at all, just tucked in a corner lol i let the aem truboost guage which uses a 3 port mac valve control the WG, i bought the gli like that with a no name stage 2 tune on it, but i have messed around with the Duty cycle and boost by gear a bunch its easy to understand with once you have like an hour of messing with it.

[B5carl]

Yea Im gonna hook up a electric fan and try to delete the viscous fan. Trying to hook up everything I can to the MFD. Even allows you to hook up a water/meth pump.

I just skimmed through the manual for boost control and it looks really involved so I'm gonna need some tuning lessons on how to set it up. I'm probably just gonna hook up a new N75 then hook it up after the car is running well.

[QuattroBucc]

Yea Im gonna hook up a electric fan and try to delete the viscous fan. Trying to hook up everything I can to the MFD. Even allows you to hook up a water/meth pump.

I just skimmed through the manual for boost control and it looks really involved so I'm gonna need some tuning lessons on how to set it up. I'm probably just gonna hook up a new N75 then hook it up after the car is running well.

does the mfd take place of your dash now? your speedo and tacho and everything? or is it just extra data and youll mount it on the side? yea using it for full boost control in the way n75 controls boost will take some time learning, youll be doing street pull after street pull dialing in desired boost and ramp of boost etc

[B5carl]

does the mfd take place of your dash now? your speedo and tacho and everything? or is it just extra data and youll mount it on the side? yea using it for full boost control in the way n75 controls boost will take some time learning, youll be doing street pull after street pull dialing in desired boost and ramp of boost etcNot yet all of this is in the near future [emoji41] lol dropped like 6k so far in parts im still saving for everything else. Also had to sell some stuff because I kept changing my mind. The amount of money you would spend on a build without planning then keep upgrading would cost a fortune and alot of time so trying to get it right the first time.

[QuattroBucc]

Not yet all of this is in the near future [emoji41] lol dropped like 6k so far in parts im still saving for everything else. Also had to sell some stuff because I kept changing my mind. The amount of money you would spend on a build without planning then keep upgrading would cost a fortune and alot of time so trying to get it right the first time.

yea parts add up lol shit gets expensive fast im over 10k on mine easy, get a fluidampr crank pulley it frees up about 20hp on high hp builds and makes the build safer, get a intercooler big enough to support the power you want, i got this https://www.ebay.com/itm/380422550188 says it more than 700cfm and supports 5-600 hp its ebay cuz im cheap lol same brand coolers are so fuckin expensive, idk why but I see a lot of BT builds running small ass intercoolers that are definitely heat soaking. Also what DV you gonna run? stock size are usually too small for BT builds and cant get enough air volume out and the turbo still stalls, i got a tial QR 50mm recirc but i hate the way it sounds honestly lol so i got a forge supersize on the way which has a 50mm bore and 40mm ports sounds like this https://www.youtube.com/watch?v=MGhXhY86qfE . definitely you save a ton of money doing it right the first time lol, the amount of shit ive ordered then had to sell, like even now i have to sell the bosch ev14s 630cc but i got sent a set of 6 before so i guess ill sell those on the s4 forum

[B5carl]

yea parts add up lol shit gets expensive fast im over 10k on mine easy, get a fluidampr crank pulley it frees up about 20hp on high hp builds and makes the build safer, get a intercooler big enough to support the power you want, i got this https://www.ebay.com/itm/380422550188 says it more than 700cfm and supports 5-600 hp its ebay cuz im cheap lol same brand coolers are so fuckin expensive, idk why but I see a lot of BT builds running small ass intercoolers that are definitely heat soaking. Also what DV you gonna run? stock size are usually too small for BT builds and cant get enough air volume out and the turbo still stalls, i got a tial QR 50mm recirc but i hate the way it sounds honestly lol so i got a forge supersize on the way which has a 50mm bore and 40mm ports sounds like this https://www.youtube.com/watch?v=MGhXhY86qfE . definitely you save a ton of money doing it right the first time lol, the amount of shit ive ordered then had to sell, like even now i have to sell the bosch ev14s 630cc but i got sent a set of 6 before so i guess ill sell those on the s4 forumI'm planning on a twin scroll EFR7670 with the full race t4 manifold for 500whp which has the integrated DV. I'm getting almost everything, a new paint job, RS4 front bumper, carbon hood, custom carbon front splitter, recaro Sportster CS seats, brembo 18z full BBK, KW V3's etc.. probably not gonna do this type of thing again on a old car though but I think the B5 1.8t quattro is definitely worth it. Plus I'm building it and doing the fab work on it myself.

Anyways, i don't have vagcom yet but does it tell you what temp the fan clutch engages? And whether it uses coolant temp or oil temp? I'm guessing coolant temperature but alot of people giving different temps on Google.

[Rmr1499]

What brand manifold are you loooking at in looking for a twin scroll manifold for my Borgwarner s200g and only one I really liked was Wig-Art out of Germany but I’m looking at like 1200-1400


Sent from my iPhone using Audizine Forum (http://r.tapatalk.com/byo?rid=87676)

[QuattroBucc]

I'm planning on a twin scroll EFR7670 with the full race t4 manifold for 500whp which has the integrated DV. I'm getting almost everything, a new paint job, RS4 front bumper, carbon hood, custom carbon front splitter, recaro Sportster CS seats, brembo 18z full BBK, KW V3's etc.. probably not gonna do this type of thing again on a old car though but I think the B5 1.8t quattro is definitely worth it. Plus I'm building it and doing the fab work on it myself.

Anyways, i don't have vagcom yet but does it tell you what temp the fan clutch engages? And whether it uses coolant temp or oil temp? I'm guessing coolant temperature but alot of people giving different temps on Google.

the turbo has an integrated DV? Idk if you want to t4 over t3 I don't think its needed for 500whp and youll probably sacrifice spool up time. thats nice i guess, nice man same here i got a rs4 front bumper, the terminator carbon vented hood, maxton design front splitter and side splitters and a custom rear diffuser and rear duckbill, vogtland coilovers with 18k front 16k rear swift springs, adjustable front and rear control arms etc, building the whole car costs a shit ton lol. Vagcom does tell you the coolant temp but not when it turns on, and whatcha mean? my clutch fan ran off the pulley is always on, 100% of the time spinning, is it not supposed to lol? I don't think my 2nd fan on passenger side that turns on electronically even works, its never come on ever, but my cars never gone over the middle temp even towing a 1500lb trailer 1000+ miles. Id highly reccomend getting vagcom asap though its a requirement for owning these cars lol you can log with it even, monitor lots of values and see ur fuel trim, reset throttle body adaptation etc, even recode some stuff like delete the rear o2 sensor through vagcom, theres a lot you can do with it and monitor

[B5carl]

What brand manifold are you loooking at in looking for a twin scroll manifold for my Borgwarner s200g and only one I really liked was Wig-Art out of Germany but I’m looking at like 1200-1400


Sent from my iPhone using Audizine Forum (http://r.tapatalk.com/byo?rid=87676)Full-race T4 tubular

https://www.full-race.com/store/vw-audi-skoda-porsche/1-8-t-longitudinal/vw-audi-1-8t-longitudinal-twin-scroll-efr-t4-iwg-turbo-manifold

[B5carl]

the turbo has an integrated DV? Idk if you want to t4 over t3 I don't think its needed for 500whp and youll probably sacrifice spool up time. thats nice i guess, nice man same here i got a rs4 front bumper, the terminator carbon vented hood, maxton design front splitter and side splitters and a custom rear diffuser and rear duckbill, vogtland coilovers with 18k front 16k rear swift springs, adjustable front and rear control arms etc, building the whole car costs a shit ton lol. Vagcom does tell you the coolant temp but not when it turns on, and whatcha mean? my clutch fan ran off the pulley is always on, 100% of the time spinning, is it not supposed to lol? I don't think my 2nd fan on passenger side that turns on electronically even works, its never come on ever, but my cars never gone over the middle temp even towing a 1500lb trailer 1000+ miles. Id highly reccomend getting vagcom asap though its a requirement for owning these cars lol you can log with it even, monitor lots of values and see ur fuel trim, reset throttle body adaptation etc, even recode some stuff like delete the rear o2 sensor through vagcom, theres a lot you can do with it and monitorYea my fan is ALWAYS on too but I wasn't sure if it's supposed to be on like that. I also don't want it like that especially if it's run off the belt and consuming power. My oil temp/level sensor wiring got cut somehow and I haven't repaired it yet so I thought that was why it's stuck on but not entirely sure.

[QuattroBucc]

Yea my fan is ALWAYS on too but I wasn't sure if it's supposed to be on like that. I also don't want it like that especially if it's run off the belt and consuming power. My oil temp/level sensor wiring got cut somehow and I haven't repaired it yet so I thought that was why it's stuck on but not entirely sure.

i think its supposed to always be on and It probably only robs like a quarter flywheel horsepower lol but if you want to go fully electronic you can get some nice fans on there, aeb don't really seem to overheat though or get that hot of oil temps even

[B5carl]

i think its supposed to always be on and It probably only robs like a quarter flywheel horsepower lol but if you want to go fully electronic you can get some nice fans on there, aeb don't really seem to overheat though or get that hot of oil temps evenYea, I'm still gonna throw one on while everything is apart

[QuattroBucc]

Yea, I'm still gonna throw one on while everything is apart

since you're going all out and probably water meth also are you gonna use VVT to improve spool/lower rpm torque/power? I bought the newer chain tensioner that has VVT so i'll be able to hookup a rpm based controller eventually, its not variable really just has 2 locking points, normal and advanced 22*, with eurodyne maestro you can use the vvt to make power and since you can do it there im sure you can probably make it work with your motoza tune and MSD control it via rpm, basically stays 22* advanced until the advance stops making power then then it cuts back to normal timing, 034 uses it to make power and they say "In general we consider VVT to be worth over 50whp and similar torque at various points in the point band, and sometimes even more in the lowend. " and if you're water/meth the timing wouldn't be an issue for you as long as you have piston to valve clearance,

from o34 "After receiving a fresh set of Cat Cams 3658 Billet Camshafts, we were able to do some dyno testing and determine the viability of utilizing the factory 1.8T VVT cam tensioner to improve the powerband of our Time Attack B5 Audi A4.

We verified clearance for up to 30 degrees of advance on the intake camshaft (the VVT tensioner itself only provides about 22 degrees of advance) on our 2.2L stroker motor with the 3658s, plugged in the VVT tensioner to our 034EFI Stage IIc Standalone ECU, and got to work.

Turning on the VVT tensioner resulted in about ~400 RPM quicker spool, and solid power gains up to ~6200 RPM. We netted gains of over 60 foot-pounds of torque at the wheels at ~4000 RPM.

Take a look at the dyno chart below, which compares one pull with the VVT tensioner turned off for the entire pull, and one pull with the VVT tensioner turned on for the entire pull.

By calibrating our ECU to switch the VVT tensioner on at low RPM, and off at ~6200RPM, we were able to combine the best of both worlds. This results in a much broader powerband, with a substantial pickup in low-end torque without sacrificing the impressive top-end power that the 3658s allow.

We strongly recommend checking clearances on your 1.8T build before attempting to utilize the VVT tensioner. Depending on the specifics of your motor, there may not be enough clearance to turn the VVT tensioner on without piston to valve contact.

Obviously, the potential gains and optimal switchover point will vary from build to build depending on the cams you’re using. For example, on stock AEB cams, there was only a ~5WHP gain at extremely low RPM. "

[B5carl]

Yea I have a 2001 AWM with wideband, VVT and also using an adjustable cam gear with the AWM small port head. When I use to be a tech my boss, who by coincidence has an AEB Passat, told me to keep my small port head to keep low end torque and it will definitely still be able to make high HP even if you don't port it since its a turbo. But that was a while ago when my goal was 400whp. Still going to use the AWM for low end and still doing a 2008cc stroker kit, IECVA2'S, SEM intake manifold, and VVT so over all it's gonna be a nice car to drive lol

[QuattroBucc]

Yea I have a 2001 AWM with wideband and also using an adjustable cam gear with the AWM small port head. When I use to be a tech my boss, who by coincidence has a AEB Passat, told me to keep my small port head to keep low end torque and it will definitely still be able to make high HP even if you don't port it since its a turbo. But that was a while ago when my goal was 400whp. Still going to use the AWM for low end and still doing a 2008cc stroker kit, IECVA2'S, SEM intake manifold, and VVT so over all it's gonna be a nice car to drive lol

I wouldn't stay small port, your buddy probably was not trying to make 650 crank HP like you are, for ko3/k04 cars even gt2867 the small port is probably better, but making big power not at all, it doesn't really increase low end torque on BT cars idk where people get that idea just because of air velocity because velocity is not all that matters, the awm is only unrestrictive up to 5100 rpm and restricted past that and im sure you're revving to atleast 7700, on dyno charts i found swapping in AEB head alone shows gains in torque and hp across the whole board... theres not any spot where the small port makes more power or torque unless maybe you are still ko3 or k04. I used to think the same thing you think and I was trying to make the most efficient engine possible and keep it smallest IC piping you can without limiting HP, smallest IC you can for the hp goals, small port head maybe just remove the casting for flow but doing more and more research between the awp and aeb head the aeb is superior in all ways when going BT, especially since you are stroking your motor now it needs to breathe MORE and especially with the cams and the small port head will be extra restrictive than it is stock lol but you can stay small port if that what you think will be better, dyno charts show otherwise though. AEB head also has larger exhaust ports at 36mm vs small port 33mm, less backpressure on the exhaust side = gains everywhere for BT, i think you should do more research and consider the aeb head/large port intake mani also, if you're going for 500whp which is 630 crank with 20% drivetrain loss I think you're gonna want the large ports, at that kind of power your backpressure is gonna be insane on small port and intake flow will be all turbulant. look at this https://www.vwvortex.com/threads/awp-vs-aeb-head.7262698/page-2#post-89802745 scroll down and find the flow maps of both heads i think its definitely possible to make 650 crank on small port but your EGTS and backpressure and boost level would all be way higher than with the aeb head, aeb would have lower egts, lower backpressure and make more power per psi

[B5carl]

Yea I know everyone uses the AEB head for high HP, I'm not doubting that but I was just considering what he was saying.

I also didn't see the flow charts either yet because I haven't really looked into it at all I just remembered what my boss told me, so there you go there's actual evidence that it will perform better at low rpm while maintaining EGT and back pressure.

I really had my hopes up for the small port but the restriction chart at the end says it all.

[B5carl]

Obviously the AEB is better but my boss made it out like you cant just assume everything is gonna be better with a large port, you will be sacrificing something for something else so you need to know how to balance it out depending on what I want. Everyone seems to want the same characteristics out of there car but more or less HP

I didn't see that thread though I'm really happy you showed me this as I got mixed up over what my boss said

[Rmr1499]

Yea you sacrificing your ability to get emissions test. I was looking at aeb heads to for my block I’m building but I’m try to keep the stock emission crap on there as much as possible for Ohio emissions and they check for all readiness monitoring and what not. Or if you save all those receipts you can do what my brother in law did and turned his receipts in and waited for approval and got collector plates on his car and now never needs emission check


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[QuattroBucc]

Yea you sacrificing your ability to get emissions test. I was looking at aeb heads to for my block I’m building but I’m try to keep the stock emission crap on there as much as possible for Ohio emissions and they check for all readiness monitoring and what not. Or if you save all those receipts you can do what my brother in law did and turned his receipts in and waited for approval and got collector plates on his car and now never needs emission check


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bro a BT 500whp car is not gonna pass emissions in any way, visual or anything, its a hot smog car at this point lol i dont think hes worrying about the head swap making him not pass emissions. idk how strict MA is where hes from but in CA even adding in a vacuum line for a boost guage makes my car illegal and not pass smog, 2.0 coilpacks? fail smog, pod filter and no airbox? fail smog, front mount intercooler? fail smog, i had to put my car back to 100% stock, going to junkyard and grabbing the side intercooler and intercooler pipe crossover bar thing that bolts into the frame rails, every single part had to be stock to pass smog lol so now building the car it is obviously gonna be one of those cars where you got a buddy to pass smog if you know you know

[QuattroBucc]

Obviously the AEB is better but my boss made it out like you cant just assume everything is gonna be better with a large port, you will be sacrificing something for something else so you need to know how to balance it out depending on what I want. Everyone seems to want the same characteristics out of there car but more or less HP

I didn't see that thread though I'm really happy you showed me this as I got mixed up over what my boss said

Glad that cleared things up for you, and if you're gonna be picking up an aeb head to build you should get a 3 angle valve job while its at the machine shop getting decked, stock heads just have a single 45* angle for the seat and that is Shit for flow, just adding in the multiple angles you pickup 10+cfm especially at low lift, not needed but will gain some power across the board and if you're gonna go all out why have a great flowing head that then gets fucked up at the valve angle lol.

[B5carl]

Yea passing emissions was something I was definitely worried about. I was honestly going to fab a high flow cat so I have both 02's with stock tune, stock injectors, stock MAF, stock throttle body and drive it up the street to one of the guys up the street from my house hoping I can pay him some extra cash to visually pass. No boost obviously I would be going less than 20mph but it is going to be stroked so I'd probably have to figure that out for a stock tune.. Anyways I kind of know the guy he asked if I wanted to a job a while back but I declined anyways, idk how he does it but I'm sure I can get the ECU to pass. I also don't think he would try to pop the hood or anything like that just the usual but it has an exhaust system, no cage etc.. haven't really looked to far into it yet but I'm sure it's possible in MA without having to swap everything. Fuck that honestly and I know there are alot of guys out there who can get around it I'm just gonna have to do more research.

Actually I saw this the other day it looks like hes running both 02's next to each other. Any idea of what he had in mind ? It looks like he has a AFR gauge also hooked up but cant figure out why he set it up like that251941

[QuattroBucc]

Yea passing emissions was something I was definitely worried about. I was honestly going to fab a high flow cat so I have both 02's with stock tune, stock injectors, stock MAF, stock throttle body and drive it up the street to one of the guys up the street from my house hoping I can pay him some extra cash to visually pass cause I kind of know the guy he asked if I wanted to a job a while back but I declined anyways, idk how he does it but I'm sure I can get the ECU to pass. I also don't think he would try to pop the hood or anything like that just the usual but it has an exhaust system, no cage etc.. haven't really looked to far into it yet but I'm sure it's possible in MA without having to swap everything. Fuck that honestly and I know there are alot of guys out there who can get around it I'm just gonna have to do more research.

Actually I saw this the other day it looks like hes running both 02's next to each other. Any idea of what he had in mind ? It looks like he has a AFR also hooked up but cant figure out why he set it up like that251941

If you find the right guy you don't even need to pass visual ;), its such a hassle part swapping back to stock. No idea why that guy has those sensors like that, or why theres even 3 sensors when hes BT, 1 is wideband and 1 egt but what is the 3rd? maybe he put in a 2nd wideband for a guage and didn't want to splice into the cars wideband o2 sensor for the guage, and then theres a spacer on one of them lol its all weird, is just 1 EGT sensor post turbo even useful? I thought egt sensors are useful when theres 1 on each exhaust exhaust runner so you can monitor which ones leaning out which ones richer etc by the temps

[B5carl]

Even if it's tuned with no rear 02? I know all it needs is to pass all the readiness codes but why did you say that CA won't visually pass you? That's insane they won't pass you for a front mount or upgraded coil packs?

[B5carl]

What I mean is I was under the impression that all I'm gonna need to do is somehow get it there with a stock tune and no CEL right? No BT tune will pass with the computer even if he approves

[Blazius]

How many times ive said use vvt tensioner always. I run aeb head with vvt btw :)

[Rmr1499]

No I get it lol but some people do worry about that. In Ohio I think you need to spend 5k plus and show proof of everything and wait awhile for paperwork and you can get “collectors” plates which is what my brother-in-law did on his focus he send In like 10k plus in receipts and for collector plates and no longer needs receipts. This is what I plan on doing. We have our own self test kiosks if not here where as long as no check engine and all the readiness monitor are good then you pass bam you get a print out of printer is working


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[QuattroBucc]

Even if it's tuned with no rear 02? I know all it needs is to pass all the readiness codes but why did you say that CA won't visually pass you? That's insane they won't pass you for a front mount or upgraded coil packs?

ya CA is strict as fuck, took my car in on stock tune but had a pod filter on and 2.0 coilpacks with adapters and front mount and guy was like GET THAT ILLEGAL CAR THE HELL OUT OF MY SHOP UR GONNA GET ME IN TROUBLE lmao, next place i took it with stock airbox and stock coils but still a front mount the guy said thats illegal and i cant have it, next time went in with stock everything cept i still had a T on the FPR vac line for my boost guage and they failed me for that lmao "modification to fueling system", now I have a guy that can get you passed through the system, not gonna say how on here lol

[QuattroBucc]

What I mean is I was under the impression that all I'm gonna need to do is somehow get it there with a stock tune and no CEL right? No BT tune will pass with the computer even if he approves

probably just pass your readyness tests if the person is overlooking ur visual, somehow my readyness tests all show passed even cat and o2 sensors on this tune

- - - Updated - - -


How many times ive said use vvt tensioner always. I run aeb head with vvt btw :)

what RPM do you have the vvt engaged and disengaged??

[Blazius]

I currently have it disabled due to tuning, however you should always keep it on until your load doesnt drop on the switchover point, this is your tuners job to find, which is pretty hard without a dyno however you can get close on road logging too.

Also I have the latest 20V head for sale, if you wanna do an absolute hybrid project :)

[B5carl]

As long as I use the stock ECU then Im sure I can get it to pass. I wanted to get a standalone MaxxECU but I guess that's not happening anymore

[B5carl]

[QUOTE=QuattroBucc;14642002]probably just pass your readyness tests if the person is overlooking ur visual, somehow my readyness tests all show passed even cat and o2 sensors on this tune

What year is your AEB? I think you can pass emissions if it's older than 97'. And your talking about the United motorsports tune right? I really doubt my motoza custom tune will pass I'd have to have a custom tune just to pass inspection with it now being a 2.0L

[B5carl]

Am I the only guy who wouldn't do a 3 angle valve Job? It looks like it ruins the valve and when they get carbon an pitting you would just have less of a seal.

It seems like it's more of a mod for a dedicated track car of drag car but for long term reliability I would just keep the 1 45° seat and use an AEB head for good enough flow.

[QuattroBucc]

[QUOTE=QuattroBucc;14642002]probably just pass your readyness tests if the person is overlooking ur visual, somehow my readyness tests all show passed even cat and o2 sensors on this tune

What year is your AEB? I think you can pass emissions if it's older than 97'. And your talking about the United motorsports tune right? I really doubt my motoza custom tune will pass I'd have to have a custom tune just to pass inspection with it now being a 2.0L

its a 99 model, and I'm talking about not having to do anything not even have a homie pass your visual... there's ways around the system if you know ppl, im not gonna talk about here lol cuz of the illegality of it. You're gonna have a hard time passing stuff when its stroked because idk how it would run on stock injectors stock tune. About the 3 angle valve job is on the valve SEAT not the actual valve, why would it ruin the valve? carbon? intake valves dont get any carbon on them its port injection it cleans the back of the valves, if you took off ur intake manifold right now all of ur intake valves would be shiny clean because gas cleans them off, and why would they get pitting unless your detonating out the ass and that would fuck up any valve regardless, I don't see any downsides to it at all, the seat shouldn't get that worn down to lose its seal or else everybody thats gotten a valvejob would be complaining shortly down the road about low compression and wouldn't reccommend it because head work is expensive lol., https://johnmaherracing.com/tech-talk/3-angle-valve-job/ they gained 10hp on a 1776cc engine just doing the 3 angles, adding a 2nd backcut angle on the back of the valve increases flow even more, to me it doesn't make sense to take a great flowing head and do a full spring set and cams but leave the horrible single seat angle holds back the heads potential flow, its not porting it at all just lets the air enter the combustion chamber way more efficiently, with the addition of cams doing a 3 angle or 5 angle job makes the cams even more efficient at the high lift they provide

[QuattroBucc]

I currently have it disabled due to tuning, however you should always keep it on until your load doesnt drop on the switchover point, this is your tuners job to find, which is pretty hard without a dyno however you can get close on road logging too.

Also I have the latest 20V head for sale, if you wanna do an absolute hybrid project :)

theres a new 20v head?and it bolts up?? I thought vw/audi went to all 16 valve enginess for 4 cylinders

[B5carl]

Yea my bad I just did some more research and realized that the ST valves come with back cuts for flow at I think 30°. I thought you ment the valve had only 1 45° face. So yea just adding more angles on both sides to smooth out flow doesn't sound like a bad idea at all. I haven't heard of the term 3 angle valve job so this is new to me. Really All their doing is using angles instead of trying to make a rounder corner by polishing it out. Infact you can't polish it out next to the face, you would have to use flat angles or else there would be no solid seal. So yea I guess I should do this then since I'm not sacrificing seal area.

[Blazius]

theres a new 20v head?and it bolts up?? I thought vw/audi went to all 16 valve enginess for 4 cylinders

Yes there was a factory "stroker" 2l 20v in Europe. If interested ill give you more info and pics.

[QuattroBucc]

Guys I need help, car is randomly misfiring at idle after the cold start, I got brand new coils and plugs in there, long term fuel trim is -3% short term stays around -3-5%, boost leak tested the car with zero leaks again. under acceleration it doesn't misfire at all, i logged the misfire counters driving down the road and it occasionaly has small misfires that I don't physically feel and the car doesn't buck or anything but vagcom counts like 10 a min driving down the road part throttle, once the car is warm at idle it the misfire counters for all cylinders go up pretty fast even up to 30-40 in a min per cylinder on some, some worse than others but the car stays idling at 900 rpm with small misfires i can hear in the exhaust note change and the counter goes up, they're like tiny misfires but its enough for the knock sensors to sense them, why is it misfiring like this randomly if everything is in check now. It scares me to take it down the road knowing its misfiring, theres no codes for misfire and it doesn't drive like its misfiring it drives really smooth so its really confusing but I don't want to do damage to the engine i want the misfire counter to stay at zero lol

[B5carl]

How new are the plugs? And are you still using the same plugs you used before you got the right injectors

[QuattroBucc]

How new are the plugs? And are you still using the same plugs you used before you got the right injectors

nah super super new, tried diff sets of plugs none are fouled and they all idle the same, right now i put in ngk 5238s gapped at .028 with feeler guage which are heat range 9, its weird because during the whole cold start when the AFR is more rich at like 12:1 it doesn't misfire at ALL, then when the rpms come down from the cold start and AFR goes to 14.7ish it starts randomly having small misfires i can hear it in the exhaust note which changes, so it doesn't seem like its mechanical like coils or plugs because theres zero misfires during the cold start, all i can think is the fluctuating AFR between 14 and 15 but thats all near 14.7 so it shouldn't be misfiring from wrong air/fuel

[B5carl]

Did you try using vagcom on your GLI to see if it does the same thing? If it's has no CEL then idk

[B5carl]

Did you restart the ECU?

[QuattroBucc]

hmm Ill try it on the GLI and see if it detects small misfires also, yea theres no CEL and its not affecting driveability its just affecting my peace of mind, I did get a "knock sensor 2 low signal" code and when i checked it the bolt was loose so i torqued it to spec 20nm and code hasn't come back, im thinking maybe its the shitty spray pattern of dekas at idle not getting full combustion maybe, who knows. Yeah I restarted the ECU and same shit happens, it doesn't affect driveability but It is definitely having small misfires at idle because since the exhaust is so loud I hear any difference in it, ill take a video of it tomorrow because its so weird, its fine the whole first minute of cold start then it starts doin that after the cold start