Tuning and Dynoing an A4

[Bruce Melton]

I think I have a slightly better than average EFILive knowledge but all M6 related.

Now I have to tune a LS1 C5 A4 which is fine, but I am absolutely clueless on the trans related changes and what to on dyno. For AutoVE do you do street tuning pulls in 3rd and what gear on dyno? Converter locked, what's that??? I am used to 3rd gear street tuning (amazed I still have valid license) and 4th gear dynos.
Anyone have a tune with moderate trans changes that I can compare to stock?

Hard to believe I got this old without any A4 exposure
Dad had some Powerglides as I remember> P,R,N,D,L
Thanks as always,
Bruce
meltn@new.rr.com

[SSpdDmon]

Well, there's quite a bit you can do with 'trans tuning' when it comes to A4s. How far I'd push things really depends on the setup.

Personally, I like making the part throttle shift tables a little more responsive. This can be easily accomplished by copying the values from the 2nd row down and pasting them in the first row (essentially sliding everything up one cell). This means, it'll ring out each gear a little longer and downshift a little sooner when you push the pedal down. One key thing is to not let the 3rd gear TCC lockup values become lower than the 3>4 part throttle upshift values. Really, it just takes some time playing around with the tune. It's fairly straight forward how all of the tables interact.

Pressures, desired shift times and torque management are things you can play with too. For starters, I'd reduce the desired shift times by 2% or so and increase the base pressures 2% or so to see if that firms things up a little. Personally, I like to lop 50% off of the torque management settings as well. Since the 3>4 shift doesn't have tq mgt from the factory, I copy the table I just modified for the 2>3 shift and paste it into the 3>4 (effectively adding tq mgt). I do this because the 3>4 shift is the weakest in the 4L60Es and if I just happen to shift into 4th at WOT, I want a little protection. Key thing here...don't go overboard increasing pressures, decreasing times or decreasing tq mgt. Go a little bit at a time. I wouldn't increase pressures more than 5~6% and don't drop shift times below .15 seconds.

As for the fuel tuning, do the normal process turning off DFCO and all that jazz. Then, just drive it normal trying to hit the cells. Get it close and move on.

On the dyno, I'd run it (in 3rd since that's the 1:1) with the TCC unlocked since that's the way it'd run at the track. Dial it in. Then, if you want to do a pull at the end with a locked TCC for a numbers pull, go for it.

The tuning aspect is not too much different from an M6. You're just dealing with an unlocked drivetrain at times. You still have the same principles when it comes to your data. Garbage in = garbage out.

I can email you my tune later this weekend if you want (from my '02 A4 f-body) along with the stock file so you can see the changes I made to the trans.

[Bruce Melton]

Many thanks Jeff.

[ToplessTexan]

Joecar had a nice little tutorial put together, can't seem to find it now though. :(

[shallow bay]

Joecar had a nice little tutorial put together, can't seem to find it now though. :(

http://forum.efilive.com/showthread.php?t=1723

[ToplessTexan]

Yes, that's the thread thanks.

[joecar]

Log the GM.TRQENG pid and keep an eye on it...

If this pid is severly dropping low (not following throttle and airflow/cylair repsonse), then something is wrong with the VE table which will cause the PCM to command the PCS pressure too low which may lead to slipping (especially when egine torque output is high) internal to the trans (will lead to failure).

The PCM uses this pid to compute/lookup what pressure to use.