TCU Tune Acting Up

[BDP]

I was curious if anyone else had this issue and if they found a fix for it. Otherwise I'm tempted to ditch my APR TCU tune for another manufacturer. When I went dual pulley I would get an issue with my launches where the car felt like it would spin, drop to neutral and bounce of the rev limiter then shift into 2nd and continue on. It's extremely violent and throws you forward as the transmission just freaks out.

Fast forward to new tires and the issue almost 100% went away. I chalked it up to too much wheel spin and crappy roads.


Fast forward again to the last few weeks and it's back. Albeit I've added a ported blower and HPFP, it's to the point I just flat out can't use launch control at all. My RPM stage is 3k and I try to feather it down to 2500 and as soon as I get into the throttle it will spin, freak out and violently come out of 1st bang off the rev limiter then grab 2nd gear and continue on. If it's not going into neutral, it's has to be extreme clutch slip and or the clutches just let go.

Here is a dragy run that shows how violent it is.

Screenshot_20190930-133456_dragy.jpg

At any rate the car still runs 11's even with that massive time and mph killer at launch. Has anyone else had this issue?

[Rodizzle]

Iv heard couple of APR guys had this before , IE is suffering the most right now . 034 had it but they recently rewrote their TCU fixing the geardrops/buckles and hesitation.
There’s some good reading on the DL501 thread .


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[Acejam]

I’ve had this with my APR TCU tune before. Dual pulley 93 57/187 + HX. It acted up the most in cold weather at the drag strip when fighting for traction, and it’s extremely violent. When I say cold, I mean 50*F and below.


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[BDP]

Iv heard couple of APR guys had this before , IE is suffering the most right now . 034 had it but they recently rewrote their TCU fixing the geardrops/buckles and hesitation.
There’s some good reading on the DL501 thread .


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O.K. I'll hunt down the thread and see what I can find out. It's cooling down here and I want to get a few runs in before the track closes in October so I've been trying to sort this out. I don't really want to switch TCU tunes if I don't have to but if 034 has a working one that rips off launches. I'd be down for it. I can literally only mash and go at this point which is not ideal...at all.

I’ve had this with my APR TCU tune before. Dual pulley 93 57/187 + HX. It acted up the most in cold weather at the drag strip when fighting for traction, and it’s extremely violent. When I say cold, I mean 50*F and below.


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It's worse for sure when it's cold out. I think when I ran this Dragy run it was 52 degrees out maybe. Did you ever fix it?

[Rodizzle]

I can literally only mash and go at this point which is not ideal...at all.

Luckily I even get it at “mash and go”

Here the thread


https://www.audizine.com/forum/showt...ssues-decision


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[BDP]

Luckily I even get it at “mash and go”

Here the thread


https://www.audizine.com/forum/showt...ssues-decision


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Thanks!

Your second launch here at the 15 second mark is EXACTLY what I get, pretty much every single time I use launch control.

https://www.youtube.com/watch?v=euB7...ature=youtu.be


If the 034 TCU tune got rid of this for you I may give it a shot.

[bhvrdr]

Thanks!

Your second launch here at the 15 second mark is EXACTLY what I get, pretty much every single time I use launch control.

https://www.youtube.com/watch?v=euB7...ature=youtu.be


If the 034 TCU tune got rid of this for you I may give it a shot.

Get the 034 tcu tune. I got it to and no more bang bang. Its a terrible shock to components when you release and grab the gear like that so i did not want it ever happening again.

[Morritse]

Welcome to the APR TCU tune :(

[BDP]

Get the 034 tcu tune. I got it to and no more bang bang. Its a terrible shock to components when you release and grab the gear like that so i did not want it ever happening again.

Yeah I just need some more time to convince myself to spend another $790 for their loader and TCU tune.

[doughboy17]

Yeah I just need some more time to convince myself to spend another $790 for their loader and TCU tune.

Have you investigated EPL's tune? Not sure how their TCU tune behaves on Stage 3.

[Geo2JZ]

I know this is not the answer anyone wants to hear and it's not a real solution but 99% of this is solved with traction. I went down to the 3000 rpm file from the 4000 file and I have made a run everyday this week with the slowest pass being 11.28. It went 11.11, 11.17, 11.19, 11.28, 11.17, and 11.21. That's Sunday to today on the dragy. Have not experienced any gear drop or loss of traction. Before I got good at predicting when the bucking would happen. Basically anytime the car spun if you stayed in it you were going to experience the gear drop so I would let off right before. I haven't had this type of consistency in a while.

So should it do the violent gear drop when it loses traction? No and it's being worked on but lowering to 3000 helped me. Looking at the screenshot you posted it was already a failed pass before the gear drop happened. You had lost traction which is why the G meter never spiked over a G.

[Rodizzle]

I know this is not the answer anyone wants to hear and it's not a real solution but 99% of this is solved with traction. I went down to the 3000 rpm file from the 4000 file and I have made a run everyday this week with the slowest pass being 11.28. It went 11.11, 11.17, 11.19, 11.28, 11.17, and 11.21. That's Sunday to today on the dragy. Have not experienced any gear drop or loss of traction. Before I got good at predicting when the bucking would happen. Basically anytime the car spun if you stayed in it you were going to experience the gear drop so I would let off right before. I haven't had this type of consistency in a while.

So should it do the violent gear drop when it loses traction? No and it's being worked on but lowering to 3000 helped me. Looking at the screenshot you posted it was already a failed pass before the gear drop happened. You had lost traction which is why the G meter never spiked over a G.

Interesting Geo ,
So are you not using FC , Just Traditional LC ?
I get gear drop even on a “smash and go” method tho .
On the latest 034 TCU I could sit there spinning wheel and not get a single issue . They use to have this issue too not to long ago so I know this is definitely fixable


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[Geo2JZ]

Interesting Geo ,
So are you not using FC , Just Traditional LC ?
I get gear drop even on a “smash and go” method tho .

I have my fuel cut aka 2 step setup at 2000 rpm. Prior to that the DSG file I was running would always have a target RPM of 4000 rpm. Some days I could manage to get traction but most times it would spin enough that I had to let off or I would get the gear drop. That is using both the 2000 RPM fuel cut or just literally flooring it from 0 speed with no launch control. It would spin both ways as whenever you floor the car it would flash too high to get traction.

Now I flashed the 3000 rpm file and kept the 2000 rpm 2 step. I can get it to hook sometimes off the 2 step but so far just flooring it from a stop without the 2 step has been very consistent and my quickest passes have all been that way. When you are at 0 ground speed and you floor the car it will still flash to whatever your launch target is and now that it's lower at 3000 I can get it to hook. Most times it just dead hooks to a 1.67-1.69 60ft and on others it just lightly hazes them to a 1.72-1.73 but what I can tell you is that every single launch has this way has been successful.

On the latest 034 TCU I could sit there spinning wheel and not get a single issue . They use to have this issue too not to long ago so I know this is definitely fixable


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So it sounds like 034 may have figured it out and like I said we know IE Is working on it but at the end of the day if you are spinning bad enough to hit the gear drop the pass is blown. I agree though that it still needs to be fixed as it is very violent and damaging.

I ordered a new camera mount the other one broke so I will get video.

[BDP]

I know this is not the answer anyone wants to hear and it's not a real solution but 99% of this is solved with traction. I went down to the 3000 rpm file from the 4000 file and I have made a run everyday this week with the slowest pass being 11.28. It went 11.11, 11.17, 11.19, 11.28, 11.17, and 11.21. That's Sunday to today on the dragy. Have not experienced any gear drop or loss of traction. Before I got good at predicting when the bucking would happen. Basically anytime the car spun if you stayed in it you were going to experience the gear drop so I would let off right before. I haven't had this type of consistency in a while.

So should it do the violent gear drop when it loses traction? No and it's being worked on but lowering to 3000 helped me. Looking at the screenshot you posted it was already a failed pass before the gear drop happened. You had lost traction which is why the G meter never spiked over a G.

I'm at 3000 rpm currently with my tune. On this run I actually let the rpms drop down to 2500 before I fully floored it so I wasn't even fully mashed down when it happened. If I fully mash down and release there is no question it will drop out. I basically feather the throttle like I would if it was a manual.

I agree it's an issue with wheel spin 100% but I have to struggle with how do RS3's and other big power Quattro cars not have this issue. I watch E85 RS3's rip out of the hole with 0 issues and here we are struggling with a car that makes less power.


Here is another run on pump 93 octane gas where I didn't have the issue.

SmartSelect_20191002-131230_dragy.jpg

Have you investigated EPL's tune? Not sure how their TCU tune behaves on Stage 3.

No I haven't but I'd be open to trying if they aren't experiencing any issues launching.

[ns8013]

Does anyone know if this is an issue for people running Stage 2 SP, or just people pushing the limits on the ECU tuning side? It seems all of a sudden everyone is having TCU tune issues (I've seen EPL, APR, IE, and 034 all mentioned) when the TCU tunes appeared to have been relatively solid for a long time. What changed that is making this such a problem across the board all of a sudden? Is it just due to the increased power people on the leading edge of tuning are starting to push?

I've watched one of your videos Rodizzle and can safely say I never want any vehicle I own to ever make a noise like I heard on it.

[bhvrdr]

Does anyone know if this is an issue for people running Stage 2 SP, or just people pushing the limits on the ECU tuning side? It seems all of a sudden everyone is having TCU tune issues (I've seen EPL, APR, IE, and 034 all mentioned) when the TCU tunes appeared to have been relatively solid for a long time. What changed that is making this such a problem across the board all of a sudden? Is it just due to the increased power people on the leading edge of tuning are starting to push?

I've watched one of your videos Rodizzle and can safely say I never want any vehicle I own to ever make a noise like I heard on it.

I never had it until the car was comfortably hitting low 11s at 123mph or so. No issues at all in the 11.5 at 119mph days.

It may indirectly related to traction but also power level. Ive had it happen when on my track tires (nt01) with good traction then not had it hapoen 10 times spinning through first on mps4s.

034 figured it out 100%. As far as ive seen posted every other tune has seen it on at least a very rare occasion with the very rare customer who has their car running well enough for the low 11s at 123+. Apr, uni, epl. Giac ive seen all post it happen.

It only happened twice to me on Unitronic out of dozens and dozens of launches ive found but since they didn't have a fix i knew i couldn't have it happen again if another company had a fix. Its not good

Heres mine. Notice i literally launched off idle mash and go and had traction then bang. I could feel it was a decent launch with a ton of torque transmitted then bang..

[ns8013]

I never had it until the car was comfortably hitting low 11s at 123mph or so. No issues at all in the 11.5 at 119mph days.

It may indirectly related to traction but also power level. Ive had it happen when on my track tires (nt01) with good traction then not had it hapoen 10 times spinning through first on mps4s.

034 figured it out 100%. As far as ive seen posted every other tune has seen it on at least a very rare occasion with the very rare customer who has their car running well enough for the low 11s at 123+. Apr, uni, epl. Giac ive seen all post it happen.

It only happened twice to me on Unitronic out of dozens and dozens of launches ive found but since they didn't have a fix i knew i couldn't have it happen again if another company had a fix. Its not good

Heres mine. Notice i literally launched off idle mash and go and had traction then bang. I could feel it was a decent launch with a ton of torque transmitted then bang..

Thanks. I don't think I'll go past Stage 2 SP with this car, so hopefully I never experience that. It sure is painful to watch those videos though, I'm surprised the DSG doesn't just grenade when it happens, it sounds so bad.

[bhvrdr]

Thanks. I don't think I'll go past Stage 2 SP with this car, so hopefully I never experience that. It sure is painful to watch those videos though, I'm surprised the DSG doesn't just grenade when it happens, it sounds so bad.

Yup lol.

I think a 3.0pr with merc hx is an amazing bang for the buck with these cars. Mid 11s at 118mph or so for about $2500 in mods with decent reliability

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