FYI a previous post .
http://www.audi-sport.net/xf/threads/bobby-singh-a4-3-0-tdi-build-thread.248899/page-7#post-2843478
I had a conversation with JD a year ago on wether any of the upgrades they conducted had resulted in any known failures on the gearbox side. The answer i got back was no. I didn't ask JD at the time what variant of the ZF 8HP the cars had. I have seen it listed as an ZF 8HP55 before but it obviously can't be if the car produces as in my case over 699 NM stock and the peak power is listed b saudi according to the A7 doc as 700NM on a 313 engine etc etc. See
*Note below.
I have also discussed the issue with my tuner and we began to briefly talk about this and the capacity to install and RS6 box but to be honest if I'm going down that route i may as well buy an RS6 in the first place and i am pretty such set on staying diesel i think. Plus there is never any guarantees that it would actually work properly against time and cost spent on it and i don't want to be the guinea pig on that mod etc etc
So it seems clear the gearbox is the weak link in all this and the question remains outstanding on what variant it is and and how high we can push the limit on it without quickly wrecking it.
Jd engineering stage 3 is normally with DPF intact but they have done some with DPF removal with marginal gains over the DPF intact route. However i.e the variance in improvement i can see on their site for stage 3 ranges between 445 - 458 BHP .
* Note As a note my car is 313 but dynoed stock at 327 BHP & 699.6 NM. So plus 19 BHP from factory. None of these engines give out the same BHP from what i have observed from the internet they all have some variances. It appears that removing he DPF gives very marginal gains. * See my list of tuning variances below.
At the time i had my car tuned the JD tuning route involved removing the ECU and cracking it open, something i wasn't keen on doing with a 3 month year old £56 k car at the time. My tune which is custom to the car is done via the OBDII port and can be flashed back to factory without detection if required for a dealer visit etc ( so they tell me anyway). Its been to the dealer several times each time being flashed on and off.
Some tuning variances:
With OEM DPF delete.
Audi A6 3.0TDI 313pk Biturbo
JB autoservice intercooler + airbox + dpf delete
JD Stage 3: 458pk & 893Nm
With OEM DPF intact.
Audi A6 3.0 TDI 313pk Biturbo
JD Stage 3: 450pk & 900Nm
Specs:
Wagner intercooler
Upgrade Airbox + K&N filter
JD Stage 3 remap
Audi A6 3.0 TDI 313pk Biturbo
JD stage 3: 455pk & 880Nm
Specs:
Wagner Tuning intercooler upgrade
Bigger air intake with K&N sport filter
JD Stage 3 remap
Audi A6 3.0 TDI 313pk Biturbo
JD Stage 3: 453pk & 911Nm
Specs:
Wagner Tuning Nederland competition intercooler
Bigger Airbox + K&N filter
JD Stage 3 remap
Audi SQ5 3.0 TDI 313pk
JD Stage 3 (intercooler / intake / software)
454pk & 896Nm
Audi A6 3.0 TDI biturbo 320pk
JD Stage 3: 440pk & 900Nm
Audi A6 3.0 TDI 320pk Biturbo
JD Stage 3: 452pk & 900Nm
Specs:
Wagner Competition intercooler
Upgrade Airbox + K&N filter
JD Stage 3 remap