Ive been trying to Tune my Corvette A6 Tranny- Ive paid for a few tunes and now Im doing my thing. Ive tried to go back to stock but for some reason my 4-5 Shift in TUTD mode is harsh. everything else seems fine
Can you tell me why or What I missed when going back to Stock...
myTM and TCC are left in play mode.
Thanks
Anybody have any ideas?
compare your factory tune with your modded tune and change accordingly. HPT will high lite differences.
2023 Ford Edge ST
2020 Ford F150 King Ranch 5.0
did that- but nothing in tranny is highlighted.Originally Posted by midevil1
You have TM disabled. Not sure your TCC mph are locking and unlocking in sinc.
Like Midevil1 said go back and do a compare.
Last edited by 8850; 05-12-2011 at 09:17 PM.
did the compare and nothing stood out there. Whay would all the other downshifts work ok? 5-4 is the only one that is harsh.
Are you sure you are using a stock 08 Corvette file to compare? Try a compare with my 08 Corvette file. I see quite a few tranny changes vs. your file.
I just compared your Stock to my Stock and they are the same.
The Above Tune has engine mods but Im trying to get the transmission where I want it.
Today I put my TUTD TCC settings back to stock to see if that would help the 5-4 shift but it didnt. It is shifting too hard.
Also last night I loaded the stock tune and all worked as it should, so I dont know what Im missing here.
I assume you mean 5-4? You stated 4-5 in your first post. It looks like your coast down spark is high which could cause a 5-4 harshness. Probably need less rpm while decelerating.
Now im lost- that is in the Engine Spark Tables> Idle Spark Coast down.
Will that affect anyhting else? What is a good formula to put in there or should I put that back to stock?
Also- wouldnt that affect all my downshifts?
I would tend to believe your problem is with your converter release speeds. For example you have release the same at 19% throttle for 4th and 5th and much higher than stock. Having higher lockup is find but try putting your release back to stock.
A high idle can have an effect on downshift. Reason for my comment about your coastdown advance. Maybe interacting with that high release mph for 5th???
I put all the TUTD Releases back to stock this morning and no difference.
let me know if i did the right tables.
May have to put the Normal releases back to stock as well.
Thanks- I will put that tune in today and try her out and post back.
No change on the 5-4 shift. All the other up shifts are flaring before the shift at WOT with the stock TCC
Might want to give this a try per Russ K. If this doesn't work then you migth have something wrong with your tranny, vacuum leak, etc. Leave everything stock except this.
"First set the Tip in TqMg, Flare TqMg, and Limit TqMg fields to none. Also set the ETC limit to disable. Leave all the trans torque management tables stock, and just halve the Cold Multiplier table. This will halve the timing retard during up & downshifts."
I couldnt find ETC... What do you mean by the Cold Multiplier
The ETC limit is already disabled in my file. For cold multiplier use this:
made the changes and got up the street. Made a uturn and the car would barely get home. in gear it would surge jerk and other things...
in N it revved just fine.
See the Scans.
I went to the Dyno shop today and…Bingo-Forgive my lack of tech talk here but… the C6 TCM has shift slippage sensors for each shift point. At one time while tuning the computer sensed this and thought my 5-4 shift was in danger (reason for the hard shift) HPTuners cant reset that part of the computer but a tech 2 can. The Dyno shop I was at today had one and viola-She is Good again.
I was telling my problem to the shop owner and he picked up the phone and called a Automatic Transmission Support Group and asked them. It was that easy.
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