Results 1 to 6 of 6

Thread: 6L80 slips at top of 4th on dyno?

  1. #1
    Tuner in Training
    Join Date
    Aug 2021
    Posts
    17

    6L80 slips at top of 4th on dyno?

    Just had my car dyno tuned and at ~6400 the trans let go and slipped to redline. Power was still building (centrifugal blower). Is there some pressure setting I should bump up to help it hold? Not sure if it was the converter or clutch packs slipping. On the graph it just noses over smoothly.

  2. #2
    Senior Tuner
    Join Date
    Jul 2020
    Location
    VIC Australia
    Posts
    1,149
    Assuming locked in gear and not converter, raise up air mass A. Results in a higher torque reported to transmission therefore trans boost valve will command more pressure. Log pcs1 pressure to make sure you see it rise and not get clipped as well.

  3. #3
    Tuner in Training
    Join Date
    Aug 2021
    Posts
    17
    Quote Originally Posted by hjtrbo View Post
    Assuming locked in gear and not converter, raise up air mass A. Results in a higher torque reported to transmission therefore trans boost valve will command more pressure. Log pcs1 pressure to make sure you see it rise and not get clipped as well.
    Thank you, I'll give that a shot. That won't affect fueling right? Also, bump it up like 10 or 15%, or bump it up to represent how much more than stock I'm making?
    I won't be able to log 4th without a dyno (would be ~180mph) but I'll see what affect it has on 2nd.

  4. #4
    Senior Tuner
    Join Date
    Jul 2020
    Location
    VIC Australia
    Posts
    1,149
    15%. Fuelling will be fine. Change the whole air mass table for now. Chance it will upset idle. Just quick dirty testing for now then can finesse later.

  5. #5
    Tuner in Training
    Join Date
    Aug 2021
    Posts
    17
    Quote Originally Posted by hjtrbo View Post
    15%. Fuelling will be fine. Change the whole air mass table for now. Chance it will upset idle. Just quick dirty testing for now then can finesse later.
    After an adapt reset that seems to be working (it was spazzy before reset). I haven't wound 4th out to test it but it shifts a lot firmer and the lower gears hold. I'll piddle with it some more to soften up partial throttle shifts.

  6. #6
    Tuner in Training JustinWhiteTuned's Avatar
    Join Date
    Mar 2017
    Location
    Houston Tx
    Posts
    39
    post tune and log file