Upshift not happening as expected

[Dan Wendling]

I have an 09 C6 Corvette and am trying to understand why my shift points for 1>2 (really the same applies to 2>3 and 3>4 but less so) are not happening at the speed (rpm) I have set. I have all the tables set the same (normal, A, B, hot, WOT, ..). I have all TPS columns 81 to 100 and WOT set to the same values and need to set the speed much lower than I expect to prevent hitting the RPM limit (6500).

Bottom line is that I have the 1>2 shift point set to 28.2 mph to get a shift to happen before I hit 38 mph at WOT (6500 in 1st with my 3.42 rear).

Tune attached, all comments welcome.

Why so early?

PS>

I have also attached an .xls that I used to compute the speed shift points. Again comments on its value are welcome.

[mostmint]

Am I correct in assuming the problem is happening with the selector in drive?

[Dan Wendling]

Yes, it happens in Drive, although I think I have all tables set the same.

I thought D uses Pattern A and S uses Pattern B?

I have not tried but expect it is the same in both.

[Dan Wendling]

forgot to add a scan .. WOT pull at frame 20440

Is there some way to edit a scan file to only include the frames of interest?

[mostmint]

For some reason I could not read your .hpt file, I got an error message.

Is it the same problem with the stock tune?

[04blackgmc]

ok so its shifting too soon or to late..

for example my MPH is 32 and rpm is 6200 it shifts are 6150..
they arent gonna be dead on so u have to try and get it close...

[Russ K]

Dan

Post your stock tune, as there are none in the tune repository. What wot rpm shifts do you want?

Russ Kemp

[Dan Wendling]

Would like the shifts at 6300 1>2, 6400 for others.

Most importantly I would like to know how to make the shift to happen where I want.

Currently it seems to have its own mind, always go past my mph settings at WOT, seems to be fairly close at below 81% TPS.

Have attached both the stock tune and my current settings.

[Russ K]

First, set the WOT shift speeds as shown, and set the WOT shift RPM to 6400. Then set the torque management tables as shown, note that multiplying the Cold Multiplier table by .25 will reduce the shift torque reduction by 75%.

Finally, set the Max Line pressure table to 275 psi, the Max Adapt volume 2-3 to 200, and add 60 psi to every X ,Y & Z Base Shift Pressure upshift table.

Russ Kemp

[04blackgmc]

First, set the WOT shift speeds as shown, and set the WOT shift RPM to 6400. Then set the torque management tables as shown, note that multiplying the Cold Multiplier table by .25 will reduce the shift torque reduction by 75%.

Finally, set the Max Line pressure table to 275 psi, the Max Adapt volume 2-3 to 200, and add 60 psi to every X & Y Base Shift Pressure upshift table.

Russ Kemp

is this safe and alright???
i have the 6l80E in my g8 and ive posted my tune on here before..

my pressure tables are 155 now stock was 105 0-2500 and 4k 97 and 7000 80
mine X& y have been increased here and there by 10-40...


btw ur pm boc is full

[04blackgmc]

after looking some stock08vette tables mine car is still lower on pressure and some other things... weird.

[Dan Wendling]

How to these changes effect the shifting and what are the risks?

Max Line pressure table to 275 psi, the Max Adapt volume 2-3 to 200, and add 60 psi to every X ,Y & Z Base Shift Pressure upshift table.

[Russ K]

That is the way I've been tuning the A6 trans for several months now. Customers are happy with the firm shifts.

Russ Kemp

[04blackgmc]

That is the way I've been tuning the A6 trans for several months now. Customers are happy with the firm shifts.

Russ Kemp

are u still running upshift and downshift tm...

[Russ K]

are u still running upshift and downshift tm...

Yes, torque management is enabled, but is now 25% of stock.

Russ Kemp

[04blackgmc]

Yes, torque management is enabled, but is now 25% of stock.

Russ Kemp

yea im looking over some tables of mine like i said i have 155PSI max..

but i do have upshift and down TM disabled..

i guess i could go back Shift torque factor and turn it down like i used to have,....

one question i used to log when i messed shift torque factor when i had TM and it seemed to directly affect timing pull on shifts and what not.
lowest i took it was .299 which should mean .29% of TM is left but never really messed around with Cold muti..
i guess this add TM to the tranny according to Trans temp im sure..


Now one BIG question NONE can answer or figured out even with upshift and downshift TM disabled and other TM settings tweaked when lets say im rolling 50 and in sport of normal and nail it there is a big timing drop till almost the end of the gear it choose..
but when holding the gear in TUTD no timing is pulled so im sure its a TM table not avaible yet..

thanks
shane

[Sneakyws6]

Russ,

Glad To See You Posting In On This Issue As It Seems Most Of Us Have Been Trying To Tune This Tranny For Several Months Now And While The Tunes Are Getting Better There Are Still Some Issues That We (black04gmc And I) Are Trying To Fix.

I See On Your Main Timing Tables You Have All Of The Timing Values 0'd Out, Are You Leaving The Timing Adder Tables Alone Or Are You Modifying Them As Well Russ?

I Will Attach My Tune Later On Tonight And If You Have Time Look At It And Tell Me What You Think?

Right Now My Only Issue Is Some Flare Shifting On My 2>3 Shift. It Just Came On Recently When I Got Rid Of The Timing Values In My Timing Adder Tables.

I Will Try To Make A New Revision Based On Your Values Russ And Try Them Out This Weekend And Based On What You See Or Advise And Other Changes As Well.

[Sneakyws6]

Well I tried your suggested settings Russ, other than the extra 60 psi being a little more firm that what I like it works great. Actually got rid of some flare shift I picked up from my previous tune. I ended up multiplying my Base Shift Tables by .90 and it got them to a more tolerable shift firmness.

Russ do you have any suggestions of what to do for a particular downshift quirk I hate. When you jump on it and the transmission downshifts it doesnt hit the downshift hard but instead acts like it i feeding the power in gradually instead of all at once.

I would rather have a nice immediate downshift accompanied by a nice rush of accleration instead of feeling like the car is a 4cl trying to wind itself out.

[04blackgmc]

well i tried something new tonight..i added some TM back in....
doesnt feel alot different but i am getting a small timing pull on shifts...barked 3rd a few times in sport mode which it only used to do before in TUTD ONLY!

sneaky u add TM back in???

according to the log with me adding a tiny little fuel back in and doing this the car has gone its fastest ever in a log...

here is the log i did also has a few WOT passes in it..

[Sneakyws6]

I made some more changes, ended going back to a previous revision and taking some of Russ's advice and some things I saw from your tune.

Really happy with it now, my flare shift is gone as of now. It hits firm and the manual mode is great. Still hs the lag on the downshift and I am sure it is because of some form of Torque Management that we cant access.

I know if I turn off the Nuetral shift feature it comes alive but is very abrupt and brutal when that feature is disabled.

For now I am running this tune, if you all want to take a look and critique please do so.

Shane email me your phone number so we can talkabout this tune and compare over the phone if you have some time.