VR6 Throttle Body on 1.8T A4?

[MikeD7]

Does anyone have this mod? Is it worth my time and are the power gains noticeable?

[v dub'n]

Anything has to be better than the factory pea shotter. I've upraded mine to a 80mm.

[Spanky387]

Rob and I did one on his A4, noticed better throttle response. sounds a little more throaty. Just make sure you wire in the pigtail right. shoot me a PM if you need to know what wires to use and not to use

[A4Rob]

yea we did it on my A4. Routing the throttle cable was the toughest part.

[biketsai]

What kind of gains did you see?

[jrodmk2]

you did the obd1 or obd2 t.b.???

[A4Rob]

I run the obd1 so it is a dbc setup.

[v dub'n]

I run the obd1 so it is a dbc setup.

but you dont run a stock computer do you? and routing the cable for my set up was a pain in the butt

[gmx]

dbl post

[gmx]

Glad a "recent" thread has come up about this.


What solution you guys use for the throttle cable routing?
Is there any material to be removed from the manifold orifice to match the TB butterfly? DBC/AEB Manifold FYI.
I'm also using the 034 adapter.


Finally, has anyone found a way to keep CC?

[Spanky387]

You wont be able to use an OBD2 throttle body. It has to be OBD1

[MikeD7]

So what exactly do I need? I'd like to make a DIY for this and I have a few friends who are interested in this mod also

[Spanky387]

OBD1 VR throttle body, TPS, TPS pigtail, adapter plate, Silicone coupler and a new IC pipe since the stock ones are rubber. Also, mustang TB's will work

[A4Rob]

Is there any material to be removed from the manifold orifice to match the TB butterfly? DBC/AEB Manifold FYI.

Yes, I just took a die grinder and bored my IM flange. I am not running a stock intake manifold also.

[gmx]

Yes, I just took a die grinder and bored my IM flange. I am not running a stock intake manifold also.

About this much?

[A4Rob]

Yea that looks about right. Nice work!

[anmagro]

I thought something like this was never a good idea on a smaller displacment engine. Wrong?

[ZimbutheMonkey]

Yeah, I'd be inclined to say that unless you're running more than a gt30, you really won't see much of a gain (if any). Has anyone done a before/after dyno or even any MAF logging? If so, was it on a GT28 or smaller turbo?

[gmx]

Yeah, I'd be inclined to say that unless you're running more than a gt30, you really won't see much of a gain (if any). Has anyone done a before/after dyno or even any MAF logging? If so, was it on a GT28 or smaller turbo?

The AEB TB is the smallest sized TB of all 1.8T engines. I keep forgetting the size but 56mm keeps ringing in my head.
There is a controlled dyno experiment thread on vwvortex with all different TB sizes though I forgot what turbo was used in the experiment.

FYI, DBW guys are using S4 TBs for setups larger than GT28. This is a 75mm TB IIRC. The VR6 is 65mm. Based on forum user feedback, (unfortunately no dynos) anything is better than the stock AEB TB, even if you're something like a K04.

[terraflata]

Apparently the RS4 TB is one of the most impressive ones. Word of mouth.

[ZimbutheMonkey]

I'm not convinced that it's worth the hassle. Here are the results from that test you mentioned here http://forums.vwvortex.com/showthread.php?4690902

Quote, originally posted by Unitronic 1.8T Engine Spec »

* Stock AWP "Small port" 1.8T Engine
* Panchi 144/19mm drop in connecting rods
* SEM Motorsport small port intake manifold + 80 x 80 throttle body plate
* Custom tubular v-band manifold
* GT3071R w/ TiAL v-band 0.63 A/R turbine housing
* TiAL 38mm MVS wastegate
* Unitronic Chipped BT 18deg file

All throttle bodies were tested doing 2 pulls at 1 bar and 1.5 bar respectively. 1 bar being wastegate pressure of 14.7psi (was actually 17psi due to the SEM manifold) and 1.5bar being controlled with a greddy unit (22psi).Below is a recording of peak power made in each dyno run using the SEM small port manifold & the respective throttle body. For reference we have included what the same engine made utilizing a stock AWP manifold and throttle body.

For this test the following nomenclature represents each throttle body.
80mm = Dodge Hemi 5.7L
75mm = Audi B5 RS4 2.7L - TT
70mm = Mercedes-Benz C320 – 3.2L
65mm = Audi B5 S4 – 2.7L / VW Golf & Jetta 2.8 24V VR6
60mm = Volkswagen Passat B5 1.8T


Cross Section Area’s of the throttle plates / Percentage increase % over stock 60mm unit
80mm = 5026 mm2 / +77.7%
75mm = 4417 mm2 / +56.3%
70mm = 3848 mm2 / +36.1%
65mm = 3318 mm2 / +17.4%
60mm = 2827 mm2 / +0%


TESTS:

HORSEPOWER / correctedhp
BOOST : Wastegate pressure - 17PSI
80mm: = 388.9 hp @ 7300 rpm
75mm: = 390 hp @ ?
70mm: = 383 hp @ 7200 rpm
65mm: = 378 hp @ 6500 rpm
60mm: = 374 hp @ 6700 rpm

BOOST - 22SI
80mm: = 451 @ 6700 rpm
75mm: = 447 hp @ ?
70mm: = 447 hp @ 6700 rpm
65mm: = 430 hp @ 6800 rpm
60mm: = 439 hp @ 6800 rpm
STOCK AWP Manifold + 60mm: = 421 hp @ 7100 rpm


TORQUE / lb-ft
BOOST : Wastegate pressure - 17PSI
80mm: = 322 lb-ft @ 5600 rpm
75mm: = 333 lb-ft @ ?
70mm: = 318 lb-ft @ 5600 rpm
65mm: = 320 lb-ft @ 5800 rpm
60mm: = 312 lb-ft @ 5700 rpm

BOOST - 22SI
80mm: = 380 lb-ft @ 5500 rpm
75mm: = 382 lb-ft @ ?
70mm: = 374 lb-ft @ 5600 rpm
65mm: = 369 lb-ft @ 5600 rpm
60mm: = 371 lb-ft @ 5600 rpm
STOCK AWP Manifold + 60mm: = 365 lb-ft @ 5100 rpm

With this being a GT3071, I'd say that the 17 PSI would be close to what a GT2860 flows at full tilt. If we look at the difference between them it doesn't strike me as amazing

60mm to 65mm 4 CHP
60mm to 70mm 9 CHP
60mm to 75mm 16 CHP

The 75mm TB may be somewhat useful, however you have to bear this in mind as per Issam:

4. Throttle body adaptations can only get you so far. Every single one of these throttle bodies needed the map to be tweaked. In no situation was it a simple “plug and go” . Some might get away with lemiwinks whereas others will have to look into an entire motronic retune.

Assuming that's the case having to source a TB, pull off and grind out the manifold, wire it in and then have to mess around with the tune. Not worth a potential 16 CHP gain. You'd probably be better off honing the exhaust manifold and turbine inlet.

Don't get me wrong, I'm all for making more power, however the bigger TB seems like more of a measure for a) those with GT30 and larger frame turbos and b) guys drag racing who've maxed out their setups and need to squeeze that little extra more out. But hey, if you want to try it out, go ahead.

[Doug@FrankenTurbo]

^ I was participating in a dyno for a mid-sized turbo on a GTi which had a VR6 TB installed. The numbers were disappointing ** and a drop from the numbers he'd seen pre-install. So the car owner pulled the VR6 and restored his OEM unit while on the rollers. Whaddaya know? His numbers came back up again. As I said, this is a mid-power level car running 300whp. He lost 10-12whp when running the bigger throttle body. That was then end of that experiment.

[MikeD7]

^ I was participating in a dyno for a mid-sized turbo on a GTi which had a VR6 TB installed. The numbers were disappointing ** and a drop from the numbers he'd seen pre-install. So the car owner pulled the VR6 and restored his OEM unit while on the rollers. Whaddaya know? His numbers came back up again. As I said, this is a mid-power level car running 300whp. He lost 10-12whp when running the bigger throttle body. That was then end of that experiment.

i dont see how this can be accurate. maybe its just a fluke because why do most BT guys go larger intake mani and TB? im sure its not to lose horse power. in the experiment above the car did not have a stock manifold. did this car on the dyno you were observing have stock manifolds?

[ZimbutheMonkey]

Given that he did it while he was on the rollers after his pulls with the larger throttle body I don't think it would be chance, bigger isn't always better.

[gmx]

Which Passat was that from? A DBW one.

The AEB is even smaller than that, FYI as I said it's in the 50s. I remember Issam saying it was 56mm and he personally did tell me that the VR6 TB on 350hp car will gain 9-12awhp coming from the AEB TB.
I took his word for it. Regardless, it's not just about peak power or even power in general.

[Doug@FrankenTurbo]

i dont see how this can be accurate.

I know. But this isn't one of those deals where "I heard about this guy who knows a guy who.." I was there to see his long face when the VR6-fitted number came up on the screen. He couldn't believe it either. After eliminating any other possibility he decided to rummage into his trunk for the old GTi throttle body and put it back on.

did this car on the dyno you were observing have stock manifolds?

As I'd said, this was a MkIV GTi, but it was modified to have the AEB manifold. So his best performance was with the GTi TB on the AEB manifold. At least that was the case at this power level. Perhaps when pushing 400bhp the larger TB will have a positive effect. But there must be something else at play here other than a simple bigger opening. Perhaps the AEB head doesn't like the flow pattern of air passing through a larger orifice?

[MikeD7]

Perhaps the AEB head doesn't like the flow pattern of air passing through a larger orifice?

I know people that port and polish AEB heads and they increase airflow but decrease velocity and it causes them them to actually make the head less efficient. the best thing to do is to put the 1mm over sized valves in the head and use titanium retainers and put heavy duty springs in. No other 20v head will flow better no matter the modification. My good friends own Haus of Dub and they just build a BT 20th aniv and it will be getting an AEB head with 1 mm over sized valves after a trip to the dyno to see what the stock AWP head does.

[Audi Skate Snow]

worthless doing unless your BT

[v dub'n]

i'll tell you what i know, when i swapped out my stock intake and tbody for 80mm wilson throttle body and aftermarket intake manifold, mide range power and top end felt better and it also put me in part of a map where i have no timing something like 15degrees. so in my book something was full of win

[MikeD7]

i'll tell you what i know, when i swapped out my stock intake and tbody for 80mm wilson throttle body and aftermarket intake manifold, mide range power and top end felt better and it also put me in part of a map where i have no timing something like 15degrees. so in my book something was full of win

are you running the stock turbo?

[v dub'n]

no im not, gt35

[ZimbutheMonkey]

Yeah, although I can see it being of benefit on a GT35, it's not really much good on 95% of the other ones.

[jettaglx91]

Does anyone have this mod? Is it worth my time and are the power gains noticeable?

on a stock turbo a larger throttle will show little to no gain it's not as critical when the air is being forced into the motor

it does start help though at around 300hp

also to the previous posts to clarify you can not use an obd1 on a stock computer as the throttle controls idle which that throttle body does not

on a drive by cable car an obd2 mk3 vr should be a bolt on affair

on the drive by wire any larger drive by wire throttle should also just simply work

[Wizard-of-OD]

on a drive by cable car an obd2 mk3 vr should be a bolt on affair

The throttle cam is incorrect
he wont have 100% "throw" of the throttle plate.
He will need a V6 Passat throttle body which is also OBD-II

Larger throttle body will show gains on a K04 and larger. I dont expect anything but better throttle response before full boost on a K03 equiped vehicle.

[MikeD7]

The throttle cam is incorrect
he wont have 100% "throw" of the throttle plate.
He will need a V6 Passat throttle body which is also OBD-II

Larger throttle body will show gains on a K04 and larger. I dont expect anything but better throttle response before full boost on a K03 equiped vehicle.

So I need one from a VR6 Passat? What generation?

[A4Rob]

So I need one from a VR6 Passat? What generation?

OBD1 for Drive by cable. Also pick up the TPS with pigtail.

[ZimbutheMonkey]

So I need one from a VR6 Passat? What generation?

No VR6 Passats only V6's. Also Issam, are you saying that a DBC V6 Passat TB is a bolt on upgrade for an AEB 1.8T?

[A4Rob]

No VR6 Passats only V6's. Also Issam, are you saying that a DBC V6 Passat TB is a bolt on upgrade for an AEB 1.8T?

B4 passat is OBD1 and has a VR6 in it.

[MikeD7]

What about one from a B3 passat? B4s went all the way into 97 which means they should have switched to OBDII in that generation at some point

[ZimbutheMonkey]

B4 passat is OBD1 and has a VR6 in it.

True, I thought he was referring to a B5 generation. So my question remains, will a B4 VR6 throttle body bolt on to a B5 AEB without having to redo the programming to accommodate it? I may have a Turbonetics 60-1 coming my way and a larger throttle body may be useful.