Rev Limiter 'Bounce'

[Dutchman1101]

Just bought 2015 R w/ APR Stage 2 (high torque) w/ 49,000 miles. Car feels great, but have noticed a few times now, w/ ESC on and off, when really getting on it will bounce off the rev limiter 3 or so times before shifting up. It will only do this once. The other shifts are normal as I go. The few times it's happened, I had just dropped it down in automatic mode. Hard drop downs too. As said, really getting on it. One thing of note, there is no TCU tune done which I know is recommended for the high torque stage 2.

Normal? Anyone had this happen to them?

One other thing of note, I'm in Denver at 5,280 ft in elevation so the wheel power numbers APR gives are cut by at least 15%. While the TCU tune is recommended for high torque stage 2, I'm not getting the 347 ft-lbs of torque APR claims to the wheels. Doing the math, at a 15% elevation loss, I'm getting 295 ft-lbs. That is well below the low torque's numbers that they say you are good with not doing a TCU tune.

Also, could not find much on this searching, but doing some Googling, I found a guy with the MK6 GTI who had a similar issue. A few folks in this thread from some random forum said it was probably a traction thing. That would be my guess too. The DSG shifts nice and smooth for the most part. Surprisingly so in fact. Especially on a car with that mileage and being stage 2 since 17,000 miles.

 

[imthanick_a]

here is no TCU tune done which I know is recommended for the high torque stage 2.

You answered your own question.

 

[Dutchman1101]

You answered your own question.

Touché. I'm either going to do that, or go backwards to the low torque map. The car is already ridiculously fast. Might not be a bad idea to back it off. The HP drop off between the maps is nothing and it's not like I'm using all that torque really ever. Only had this come up because I was testing the limits of the new car.

Do you or anyone else have any thoughts on the elevation point I made above? I'm not putting down the 347 wheel torque APR claims that makes them recommend the TCU tune. Due to me being at 5,280 feet in Denver, I'm putting down around 295 wheel torque (15% loss).

http://www.wallaceracing.com/braking-hp.php

 

[Dutchman1101]

So, I talked with a guy at APR over the phone. Mentioned how the site recommends the TCU tune with the high torque. He said yeah, but not it's not that big of a deal if you do not. This is coming from a salesman mind you. Dude was quite nice and did not seem like he just wanted to get me off the phone (if that even makes a difference). He said, yeah it helps, but it's not a critical as the site makes it sound. YMMV...

Also, like I mentioned above (which I also talked to the APR guys about), I'm not pushing the same torque to the DSG and wheels as you sea level guys are. APR's site says 347 wheel torque. If you factor in a 15% elevation loss (it could even be higher mind you), I'm only pushing about 295 torque. He said this does play a factor as well, as you simply are not pushing the DSG as hard as if you were at sea level.

HP Loss at Altitude Calculator: http://www.wallaceracing.com/braking-hp.php

Thoughts?

 

[kgmm/sss]

Altitude loss calculators are not valid for forced induction vehicles. To an extent the turbocharger via the ECU will compenstate for the lower air pressure.

 

[Dutchman1101]

Altitude loss calculators are not valid for forced induction vehicles. To an extent the turbocharger via the ECU will compenstate for the lower air pressure.

This is true, but you do lose some power. It's not like you are running sea level numbers...

Also, an update. Essentially I was simply hitting the rev limiter. In one case, it was the hard rev limiter, but not a DSG issue like I was concerned (knock on wood).

This guy does this w/ an APR tuned GTI at the :11 & 1:58 marks. My hard rev limiter was a bit more intense, but essentially the same. The soft one or two were just like this...

https://www.youtube.com/watch?v=pr3aM5jA6nI&t=21s

 

[Rafal]

Just bought 2015 R w/ APR Stage 2 (high torque) w/ 49,000 miles. Car feels great, but have noticed a few times now, w/ ESC on and off, when really getting on it will bounce off the rev limiter 3 or so times before shifting up. It will only do this once. The other shifts are normal as I go. The few times it's happened, I had just dropped it down in automatic mode. Hard drop downs too. As said, really getting on it. One thing of note, there is no TCU tune done which I know is recommended for the high torque stage 2.

Normal? Anyone had this happen to them?

One other thing of note, I'm in Denver at 5,280 ft in elevation so the wheel power numbers APR gives are cut by at least 15%. While the TCU tune is recommended for high torque stage 2, I'm not getting the 347 ft-lbs of torque APR claims to the wheels. Doing the math, at a 15% elevation loss, I'm getting 295 ft-lbs. That is well below the low torque's numbers that they say you are good with not doing a TCU tune.

Also, could not find much on this searching, but doing some Googling, I found a guy with the MK6 GTI who had a similar issue. A few folks in this thread from some random forum said it was probably a traction thing. That would be my guess too. The DSG shifts nice and smooth for the most part. Surprisingly so in fact. Especially on a car with that mileage and being stage 2 since 17,000 miles.

I have the same issue and APR already supplied three updates and none of them worked.
I kick down in 3rd, DSG goes to 1st and at WOT maxes out RPM and hits the limiter at 6980RPM. It bounces three times and shifts. The same if I take off in 1st, but not always. Totally ruins every race at the drags.
It does it once, then the next time it shifts smoothly at 6500-6600RPM depending on load (flat or uphill)
I asked why can’t they force the DSG to upshift at 6700RPM, but they couldn’t answer.
Instead they asked us to log the DSG, which we haven’t done. It’s nothing to do with traction. There is no wheel spin when that happens. Certainly not long enough for three bounces and smashing my face into the steering wheel.
I have UM Haldex Tune and my traction is brilliant. This is DSG failing to shift at 6700 RPM and going hard close to 7000RPM where the brick wall of safety is standing.

 

[jimlloyd40]

I have the same issue and APR already supplied three updates and none of them worked.
I kick down in 3rd, DSG goes to 1st and at WOT maxes out RPM and hits the limiter at 6980RPM. It bounces three times and shifts. The same if I take off in 1st, but not always. Totally ruins every race at the drags.
It does it once, then the next time it shifts smoothly at 6500-6600RPM depending on load (flat or uphill)
I asked why can’t they force the DSG to upshift at 6700RPM, but they couldn’t answer.
Instead they asked us to log the DSG, which we haven’t done. It’s nothing to do with traction. There is no wheel spin when that happens. Certainly not long enough for three bounces and smashing my face into the steering wheel.
I have UM Haldex Tune and my traction is brilliant. This is DSG failing to shift at 6700 RPM and going hard close to 7000RPM where the brick wall of safety is standing.

Have you ever gotten an EPC light because of that?

 

[dwvw]

Our cars use torque target tuning. Throw everything you know about altitude out the window. Our cars will try and make the torque by increasing boost and timing. Get a DSG tune, it's required even at stock power levels in my opinion.

 

[Rafal]

Have you ever gotten an EPC light because of that?

No

 

[mto386]

It's a miss match of when the transmission is expecting the engine to cut power to shift. Stage 2 dsg should help this. When I was stage 2 like you, I had no problems. They offer the 30 day money back guarantee so why not try it out and see if it makes a difference.

 

[Rafal]

It's a miss match of when the transmission is expecting the engine to cut power to shift. Stage 2 dsg should help this. When I was stage 2 like you, I had no problems. They offer the 30 day money back guarantee so why not try it out and see if it makes a difference.

I have stage 2 everything and it doesn’t work.

 

[SugarMouth]

TCU tune needs to be matched to ECU. I believe the TCU rpm is a bit higher than the ECU to prevent.