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Thread: 6L50 Shift Pressure help

  1. #1
    Tuner in Training
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    6L50 Shift Pressure help

    I have increased the torque of my 2.8 Duramax truck about 20% with the engine tune now I need to address the trans and I'm learning as I go.
    So I guess with this extra power I'm going to slip the trans more that it should and could cause damage?

    Should I increase the shift pressures for each gear, what is a starting increase 10%?
    And what about the Max Line Pressure?

    Also if I lowers my shift speeds do I need to then adjust my TCC apply/release speeds?

    TCM T43

    Thanks for any help
    T43.png
    Last edited by Peasy; 10-11-2020 at 05:56 PM.

  2. #2
    Tuning Addict 5FDP's Avatar
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    Leave the MAX line pressure alone, I've never touched that on stock or mildly modded V8 engines with 6 speed auto.

    Increasing the shift pressure slightly for gear is fine, I do that all the time.

    I tend to lower the shift time torque adder (shift time) down to around .3000 for a nice shift without being too fast and I also slightly up the oncoming pressure presets for gears 1-4. Doing pressure changes like that means you need to reset the adaptive presets in the computer using the VCM scanner after flashing and prior to driving the vehicle. This way the new changes learn.


    Adjust the TCC settings as you wish. It's up to you if you want the converter locked/unlocked at different speeds and if you want the shifts to happen at different speeds.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
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    Thanks 5FPD what’s the process with the reset, in park key on?
    Last edited by Peasy; 10-11-2020 at 11:12 PM.

  4. #4
    Tuning Addict 5FDP's Avatar
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    It's the same as always, flash the tune, open the scanner and connect to the vehicle and use the special functions tab to reset the presets.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    Tuner in Training
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    Ok when I push reset nothing happens I thought it might say complete or something?

  6. #6
    Tuning Addict 5FDP's Avatar
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    Correct, nothing shows up. Click reset and then preset, that's it and start the vehicle. If it worked you'll notice it on the first couple times through the gears as it adjusts.

    This is HP Tuners we are working with and not a GM Tool designed for the vehicle.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.