Golf R - APR Stage 3 Upgrade

[Deadpool]

Originally I thought it was the DSG dropping torque as a way to prevent clutch slippage, but turns out it's the ESP cutting power for a moment when the turbo hits peak boost. At that point the boost jumps from ~20psi to around 30psi almost instantly which I guess might seem to the ESP sensors like the wheels have dropped onto a surface with much lower grip, hence the ESP pulls back the power for just a moment.

There are a few little things left to sort out so the next time the car goes on the dyno we'll do some runs with ESP disabled (by fuse) to confirm the hypothesis.

Ahh yes, I've heard heaps of things on Vortex about pre-MY12 not being able to full defeat the ESP. Also, jesus 30PSI! That's insanely high.

[Pullstarter]

Awesome result James, be sure to let us know how the car goes reliability wise. Modding a car that heavily kind of scares of me a bit lol. But I must say the results are the nuts!

[jamesatfish]

Awesome result James, be sure to let us know how the car goes reliability wise. Modding a car that heavily kind of scares of me a bit lol. But I must say the results are the nuts!

Will certainly report back on the long-term reliability of the car once all the teething problems are sorted.

It's my daily driver so I don't want a car that's anything other than bulletproof - the clutch upgrade is a certainty and I'm prepared to go to a Stage 4 built motor if there are any reliability concerns with the engine internals, but at this point I can't see that being needed unless I can't shake the itch for more power...

[jubei]

Golf R - APR Stage 3 Upgrade

good luck james, hope the issues are sorted soon.i hate that feeling in ur gut when somethings not right with the car.

[jamesatfish]

I took advantage of HPA Motorsport's sale and picked up a Gen 4 Competition Haldex controller to replace the stock unit, and installed it last night. Woke up this morning to overcast skies and wet roads so the perfect opportunity to test it out.

I have now decided this should be a mandatory part of any Stage 3 / big turbo build for the Golf R.

With only limited testing to and from work today, it seems the 'lag' in acceleration that I had previously described has all but disappeared. Where I had been getting a slight pause in acceleration at the moment the engine hit peak boost there is now only strong acceleration through the rev band - so I'm assuming that the previous behaviour was in part the result of the Haldex controller making changes to the torque split when the sudden spike in power overwhelms the front wheels.

With the competition controller the rear wheels are sent power far earlier in the rev band and that lag I'd been experiencing seems to be gone.


The dyno graphs stolen from the HPA website explain things more clearly:

Stock Controller
The lag I was trying to describe seems to occur around 3500rpm - the same point where the stock controller seems to increase the amount of torque being sent to the rear wheels. Note the gap at that point between the power being sent to the front versus the back wheels.




Competition Controller
With the competition controller the front/rear split is pretty much constant all through the rev band, so there's no lag caused by the controller changing the torque split when the engine hits peak boost.




All in all I'd strongly recommend the upgraded controller to anyone looking at a big turbo upgrade for their R.