8L90 Manual mode tuning(TUTD)
 

Just wanted to share some information for those looking to maximize their A8 performance when doing a roll.

What I have always found annoying with the A8 is that when going from a Roll, you either leave it in Drive and let the trans skip shift on it's own (which is slow if roll racing), or you put the shifter in manual mode, select the gear you want to do a pull in, then floor it, and move the shifter back to Drive (so the computer takes over). That works fine when you are stock or mild bolt-on but can be hit or miss when you start making more power and the car accelerates much quicker in the lower gears.

After the Whipple build, I found that when doing a low roll from first or second, the trans would no longer shift consistently from 1st or 2nd gear when moving the shifter from manual to D. The engine pulls to quick through the RPM band to make the shifts on time. It would either be short shift or touch the limiter. So I knew there had to be a better way.


I was on FB reading some posts by Brett @ PrayPerformance about Manual Mode Roll tuning. Then it dawned on me that we can edit the TUTD tables that control Manual Mode. If you look at these tables, each gear is set the same mph at all tps % to a number that the ECU will never see before reaching the REV limiter. So this means you have to manually command the shift. That is ok, but we all know the computer does a better job with the shifts. So I started messing with these tables and was able to get my transmission to shift at commanded MPH in each gear without needing to move the shifter over to D.

Here are the benefits of doing this.

1) The ability to leave the gear selector in manual mode without worrying about moving the shifter back to D to let the computer shift.

2) Now you can modulate the throttle if the tires are spinning and the computer will not short shift. It will stay in the same gear until X mph is reached to command the shift.

3) No more forgetting to move the shifter back to D after doing a burnout and hitting the limiter after launch because you forgot to move the shifter back to D.

4) Much easier to dial in the shift points and get consistent shifts because you don't need to off set with a bunch of lead time in gears 1 & 2.

5) You still can enjoy manually shifting the car for spirited driving just like before, the only difference is once you reach commanded MPH the Trans will shift on it's own.

Below are pics of the Stock TUTD settings( Pic 1-3) vs My TUTD settings (pic 4-6) for reference.

I tried this exact thing and wasn’t able to get it to shift. I dropped the numbers pretty low with no luck.

I was able to tune out 1st in the manual mode which I wasn’t able to do in the auto modes.

My process for racing at the track is keep it in manual mode for the burn out and launch then slap it over to auto. This gets me a 2nd gear burn out and launch without touching the shifter.

Then you did something wrong because it works well. 3 tables need adjusted for it to work. Brett has been doing this for his customer's tunes for a while now.

I hope you are right, I will look at my tunes when I get home. I do know the 17’s are flaky with the trans stuff unless it is just a problem for me. You can’t do a read and see what is in there.

That is odd...

One thing I had to make sure was all 3 tables lined up perfectly.

I need to send my TCM out and stop slacking. No excuses now that cooler weather is upon us. I can’t say thanks enough for sharing. I probably have enough of your shared information to fill a 2” binder.

No problem! :)

This is good stuff. Nice job!!

Thanks!

Now to get this working on my I4...

I have set 3 tables and mine doesn't shift either. Do you have TUTD enabled by chance? Mine is disabled.

Attachment 1015326

That's disabled on mine too. The changes worked for me. I can slap it over into manual mode, take off from a dig and it'll shift automatically into 2nd at 33mph (which is what I have it set at).

Thanks for the reply.

I think that mine was working the whole time with the settings from KingLT1. I was just uneasy about the high rpms. It showed 6700 rpms when it was performing the shift on the log. Also not sure the transmission was completely warmed up. Had 200 rpms of TCC Slip. I had the settings at 62 and 6300 rpm. It was actually shifting at 62 and revving all the way to 6700 rpm on the shift. I let out of the gas when it got to 6500 rpms. I just saw 6700 rpm on the log and thought it wasn't working.

I just changed 1>2 shift to 33 like yours and 2>3 shift to 60 and 6200 rpm and it shifts much better for me. When it shifts now, it only gets up to 6475 rpms. Can adjust later when I am more comfortable with it.

Thanks again

Yep....You need to command the shift early, especially in 1st gear. At WOT, I command the shift at 33 mph, but it actually shifts at about I dunno 36-37mph not really sure, but the RPMs are around 6700-6800.

Use MPH to set your shift points, not RPMs. And command it before you actually want it to shift at. The shifting looks at MPH first. Example..you said you have your 2>3 shift at 60mph and 6200 rpms...and you saw it rev to 6700. that 6200 meant nothing.