wcrmltd

What kind of HP and TQ changes has anyone seen on just the HP tuner work. I have a 2008 C6 with automatic.

craftfox

Be carefull letting people talk you into tuning it, lots of tuned a6s explode, where as stock ones with just MILD changes, live under alot of power for a long time.

DSteck

Most of the A6s that fall apart are a result of the tuner not keeping the numbers "true" which results in bad torque calculations and broken parts.

wcrmltd

DSteck, can you explain what "true" means? I am very familiar with Mitsubishi Evo's and Dodge SRT-8 (Magnum) tuning, but I do not catch what you mean by keeping the numbers "true" on the Vette.

My 06 2500HD Duramax/Allison had communications from the ECU to the TCU so that the engine would defuel between shifts in order to keep the tranny alive, and my MSRT-8 has a TQ controlling algorythm that some tuners turn off or defeat. Is there something similar on the A6's in the Corvette hat needs to be left alone?

Thanks

0ian@thetuningschool

The A6 in the vettes does have TM during the shifts, were it pulls timing during the shifts. You can remove if you like, leave it alone if your worried about the life of the transmission.

Ian

DSteck

I don't know the specifics, but the transmission controller (and consequently the transmission) isn't happy when the reported torque is totally wrong. It's more a result of a raped PCM calibration.

BAIN

You can also reduce the amout of TM insted of all or nothing.

8850

On upshift you can reduce TM by simply shortening shift times but I have found no way to reduce on downshift. I've tried working with Base Power downshift, Base CT downshift, Downshift Normal, Shift Torque factor, Shift Torque Factor Adder and more and nothing seems to eliminate the slow downshift from 25 mph and up. If you know the trick on partial TM reduction on downshift I would like to know. Downshift from 25 mph and up are granny slow!

I'm thinking maybe it's in the spark tables rather than TM?

BAIN

To be honest with you I haven't messed to much with the downshift. I don't drive around hitting it at low speeds to see how fast it downshifts. I think if anything getting rid of the TM during downshifts could damage a tranny worse than on the upshift.
It may be just my thinking here, but on the upshifts as the rpms go up the torque is being decreased. On the otherhand if the tranny downshifts from say 2-1 the torque would be multiplied because of the lower rpm and lower gear. To me that would shock the internals of the tranny.

Who knows I may be totally off on the thinking

8850

You may be right on downshift having more of a detrimental effect than upshift. But over a second from 5-1 or 6-2 to shift seems overly conservative when the 4-1 takes less than 1/2 second. I don't want all TM/advance eliminated just some. You don't have to be at slow speed either. Even at 55 mph it slow to power.

I have taken friends for a ride and they have mentioned how long it takes to power after WOT.

ConceptLSX

CT downshift means Closed Throttle downshift so this will not do anything when trying to make it downshift faster when you're gettin on it. And like Dsteck said, make sure your VCM tune is correct before you dial in your TCM tune, line pressure and shift times are based on delivered engine torque and temperature for the most part, and if you airflow and spark tables are off, your shifting will be too.

wcrmltd

I agree with you on which will cause more damage if the down shift is because you are downshifting to accelerate. if the down shift is done during de-celeration then the harm is min. any shift where the power is going to be applied then the computer is going to assue clutch lock prior to letting torq come on. I am going to LG motorsports Monday to talk about the changes.

I would like to see if any members with automatics have had the TM turned off with the LG tune and what issues if any they had.

da vette guy

Larry,thought you got your shifts where you wanted them..

8850

After more testing I found out that only below 25 mph was TM where I wanted. Takes about .4 to downshift with some advance reduction below 25 mph but anything above 25 mph is over a second with lots of timing reduction.

wcrmltd

can you tell me the different sections that control torq and how each affects the car. or can you point me to a site that can explain the TM.

8850

You can find out a lot about TM and our A6 tranny on the HP Tuner forum: http://www.hptuners.com/forum/ But to find someone that knows this A6 well may be difficult. The pro tuners can make the tranny perform well on upshift but nobody has been able to tell me what to do to reduce TM during downshift. I've looked at some of their tunes and from all I've seen they just disable TM altogether. That's not quite what I want to do. And the things they have done to partially disable that I've tried did not work. I can get my downshift down to .438 seconds below 25 mph and it feels good. 25 and above no where near that close.