New A6 Transmission parameters walkthrough

[Bill@HPTuners]

When I first downloaded the tune for my car I had a lot more options under the "Shift Properties" tab. Now I only have the following options showing up. How can I get the rest of the properties to show up?

Looks to me like you are using a very old public version. Update your software.

[Tapout Tuning]

Has anyone else seen this sort of problem with their A6?

High horsepower A6 won't upshift

[bluessv]

Can someone please explain this??

When my trans changes from 2-3 normally the scan indicates a shift time of 0.3 to 0.4 sec. This is right on the money when you add the Desired Shift Time plus any adders.

When my trans changes from 2-3 with a flare (which seems to me to drag the shift out with a slight increase in engine RPM) then the scan indicates a shift time of 0.2?

That time is way to quick for the stock tune as the Base Desired Shift Time is 0.3496 and then any relevant adders are all positive not negative.

So is there anyone out there that could explain why the trans would be seeming to flare and drag the shift out except the scan tells me that the shift time is 0.2??

[midevil1]

GM has at least 8 updates for the A6. Have you had any of them done. I know one is for flare shifting. 1 for clunking,ETC.... I know the flare shift is not a software issue. My Denali barks all 4 in the 2-3 shift. I have had all the updates done.

[bluessv]

Yeah I've had all the updates completed. The TCM is from a 2009 build and is completely up to date.

I have disabled the Discrete Shift Torque which was only enabled on the 1-2 and 2-3 shifts anyway. I've also adjusted the Base Shift Pressures on all tables (X,Yand Z). I have also increased the Max Adapt Volume on the 2-3 shift from 40 to 200 to bring it in line with all other shifts.

The most interesting thing was when I changed the Clutch Control Mode in Pressure Pattern Z from "Special" to "Normal".

As a result of all the chnages I can basically get my trans to shift beautifully in TUTD mode, but when it's in "D" or "Sports" it just seems like the TCM can't get the shift right. It will be fine for a few shifts (with scan telling me the shift time is between 0.3 and 0.4 secs) and then it will flare and drag out the shift a few times (with the scan telling me the shift time is 0.2 secs). Which I've said is WAY to quick for the shift.

It's just got me stumped as to why the TCM can't get the shift right when it has to manage the shift but is fine when in TUTD mode and I tell it to shift??

NOTE!! The other weird thing is that from a cold start the trans changes perfect in all driving modes until the trans temp reaches roughly 170F and then it starts to flare.

[[email protected]]

It may be related to the torque the transmission is anticipating to see, we've been scanning on a new G8 GT. The scan log seems to indicate a higher than expected delivered TQ when the flare happens, but I'm not 100% on that yet...

Bob

[bluessv]

Oh ok.... So does that mean that the clutchs would be applied quicker than normal because of the higher TQ reading and thus the shift time of 0.2 instead of 0.3 or 0.4. And then that weird shift just feels like a flare??

[camarochevy1970]

What is everyone using for base power downshift times? We are looking to try and cut back on the time it takes on the multiple gear downshifts. I know we can only do so much, but any little bit would help

Thanks

[ktoonsez]

bluessv:
Just want to make sure that you noticed and then adjusted all the tables to be the same adders and pressures for the change in trans oil temp? As the temp goes up (this is in my '08 corvette) almost all of my shift pressure tables command less pressure as the temp goes up.

[bluessv]

Yeah I have been looking at that. I have actually adjusted my pressure on the 2-3 shift slightly lower than stock and has significantly improved the change.

The stock tune calls for 340kpa at 0nm torque and 500kpa at 300nm torque. I have actually lower this to 300kpa at 0nm and 400kpa at 300nm. All which is selected with Discrete Shift Torque on that particular shift.

After about 4 or 5 shifts the Adaptive Pressures (Learning) kicked in and now the trans shifts great. I always thought the trans needed more pressure but from the looks of things my specific trans seems to need less; and then the "Learning" just corrects it. I think the flaring issue may have been the base pressure set slightly too high and the Adaptive Learning was constantly kicking in and lowering the pressure (thus the flare).

I will say though that my trans is suffering this problem unlike others....But if there is anyone out there that is having a flaring issue, even when hot, try lowering the base pressures slightly as an experiment and see if it works for you too??

[bluessv]

Oh....And I also adjusted the Torque Management (Shift Torque Factor) on all shifts from "1.000" to "0.7002". Just in case the TQ Management was pulling too much torque and possibly confusing the TCM during the shifting when it was looking up shift pressures based on the TQ profile.

But this is only a theory...

[midevil1]

I think the G8's TCM has issue's all it's own. I haven't experienced any of the issue's with any of the truck app's with the A6.

I would never lower line pressure below stock settings. Factory settings are already VERY low. If lowering line pressure helps the tranny shift "correctly".....then I would be looking into a mechanical issue. Improper clearances in the build to begin with or faulty parts. (Have SEEN misbuilt trannies already) The A6 is complicated and is VERY HARD to troubleshoot without actually driving and looking at parameters. I personaly raise all the factory shift pressures by at least 40psi, but it is a combination of this plus times, torque, speed, ETC.....

[bluessv]

Hey guys,

Can someone please explain to me what the differences are between the new TQ Management tables (Tip-In, Flare and Limit). And can someone also explain what the differences are with the various settings you can slect (None, No Throttle and Throttle Only).

I've tried to get the answer on the thread discussing the new tables under the forum of Product Info, however haven't got a response for quite some time.

Thanks!!

[midevil1]

Hey guys,

Can someone please explain to me what the differences are between the new TQ Management tables (Tip-In, Flare and Limit). And can someone also explain what the differences are with the various settings you can slect (None, No Throttle and Throttle Only).

I've tried to get the answer on the thread discussing the new tables under the forum of Product Info, however haven't got a response for quite some time.

Thanks!!

In a hurry to catch a plane, but i believe Chris explained these items earlier in this thread.

[04blackgmc]

looks like i have alot to read

edit just read it all... learned ALOT

[04blackgmc]

ok i did some changes to mine based off some other tunes and reading this thread..



i have one slight problem on the 1-2 downshift in sport and normal mode in WOT it has a lag going on...when i had my superchips cortex tuner this wasnt as bad.. also in manual mode it gets rid of it..

[bluessv]

Hey guys,

When you guys are making changes to the shift times to achieve a quicker shift and feel (either by Base Shift Times or in the Adders), are you also making any changes in the Shift Time Transition (Initial or Final) or any changes to the Desired Output Torque?

[johnh]

I use shift time, shift torque factor mostly. I have made a few tweaks to the others..mostly on specific shifts (3-4 in the G8 seemed to shift as well, so I changed the torque profile a bit--hard to test WOT 3-4 shift out though.)

[midevil1]

For quicker shift "feel" you need to adjust Inertia Factor profile upshift, CT Downshift profile, power downshift. These combined with the correct timing and torque will produce a VERY positive up and down shift.

Start with the 1-2, 2-3 shifts. After you have mastered these then move on to your skip shifts. Small adjustments or breakage will occur. Bigger is NOT better in this case.

[BMBSALES]

Yeah I have been looking at that. I have actually adjusted my pressure on the 2-3 shift slightly lower than stock and has significantly improved the change.

The stock tune calls for 340kpa at 0nm torque and 500kpa at 300nm torque. I have actually lower this to 300kpa at 0nm and 400kpa at 300nm. All which is selected with Discrete Shift Torque on that particular shift.

After about 4 or 5 shifts the Adaptive Pressures (Learning) kicked in and now the trans shifts great. I always thought the trans needed more pressure but from the looks of things my specific trans seems to need less; and then the "Learning" just corrects it. I think the flaring issue may have been the base pressure set slightly too high and the Adaptive Learning was constantly kicking in and lowering the pressure (thus the flare).

I will say though that my trans is suffering this problem unlike others....But if there is anyone out there that is having a flaring issue, even when hot, try lowering the base pressures slightly as an experiment and see if it works for you too??

I currently have C6 with A6, sts-v with A6, and an escalade with A6, and all three have the same 2-3 flare, ecspecially when cold. they all have the new gm flashes, one of which was specifically for flare (cad ext), and nothing has cured the problem.