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Thread: Car falls on its face at take off-timing drops to 0-cause? scans/tune attached

  1. #1
    Advanced Tuner Justinjor's Avatar
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    Car falls on its face at take off-timing drops to 0-cause? scans/tune attached

    Hey gang,
    I've got a weird tuning issue that has come up and I'm not sure of the source.

    When I try to accelerate from a stop, the car momentarily falls on its face, then comes right back. The timing drops to 0 then comes back. Aside from that, the car is running good.

    You can see the issue at frame 104-138 in the first scan, 60-125 in the second scan.

    I've attached the tune, scans, and config.

    Any help is greatly appreciated. Please forgive my ignorance on what is needed to diagnose something like this. If any additional information is needed, please let me know.

    Thank you

  2. #2
    Advanced Tuner vette_c6's Avatar
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    would you mind posting your original file ,,,
    if you changed your stock file ,,, then i would like to see the original file please

    specialize in: V8 Tuning (Kuwait)
    Abdullah Al-najdi
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    best number in 1/8 mile 4.54 ( My Driving + My Tune ) !

  3. #3
    Advanced Tuner Justinjor's Avatar
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    Definitely. It's at home but I can post it when I get out of the office.

    Only thing I changed was timing and the maf calibration.
    Timing was changed from .76 dyncylair and above so I didn't think that would have any effect on the idle/take off.

  4. #4
    Advanced Tuner vette_c6's Avatar
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    i still would like to look at it if you dont mind

    what modification have you done to your car ? i am assuming that the car was running perfect before you do any modifications and any tune ,, right ?

    specialize in: V8 Tuning (Kuwait)
    Abdullah Al-najdi
    00965 99369929
    www.youtube.com/alnajdi83
    Tuners ! Quit Raping your PE TABLE !
    instagram : alnajdi83
    best number in 1/8 mile 4.54 ( My Driving + My Tune ) !

  5. #5
    Advanced Tuner Justinjor's Avatar
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    Cam and bolt-ons LS3.

    I'm just trying to figure out what could cause the car to do what it's doing in the logs I posted. It happens everytime I take off, otherwise it drives just like it did before.

  6. #6
    Advanced Tuner vette_c6's Avatar
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    i am not the expert guy here
    but
    i would like to to
    1- post your original file
    2- write calibrate for your Stock file and scan it again
    and post your log ,,,

    or u can wait for more experience guy then and he could give the answer

    specialize in: V8 Tuning (Kuwait)
    Abdullah Al-najdi
    00965 99369929
    www.youtube.com/alnajdi83
    Tuners ! Quit Raping your PE TABLE !
    instagram : alnajdi83
    best number in 1/8 mile 4.54 ( My Driving + My Tune ) !

  7. #7
    Advanced Tuner Justinjor's Avatar
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    Ya, I can do that when I get home tonight. I don't have the computer with the tuning software in front of me.

  8. #8
    Senior Tuner IDRIVEAG8GT's Avatar
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    This is an M6 Vette?
    Gray Ghost- The abomination. 2007 Chevrolet Silverado CCSB. 98mm turbo, nitrous, 428LSX, Rossler 80E with a brake. Finally finished. 23 psi, no numbers, Slow as hell.

    PBM G8- Aluminum 364, twin Precision 67/66 turbos, 6L90 trans swap, CTS-V/Vaporworx fuel system, slowly making progress.

    Dads 2011 CTS-V- Stock bottom end, stock heads, LS9 cam, pullies, ported blower, ported TB, D3 goodies, and lots of nitrous.
    618/618 motor
    906/862 spray

    Caterpillar 50 Forklift- Duramax swap

  9. #9
    Senior Tuner Russ K's Avatar
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    Seen that happen before when raising the Torque Management tables too high or maxing them. Just try raising them to more closely match the actual output of your engine.

    Also log Burst Knock, Launch-Advance and Torque Mgt Advance.

    Russ Kemp

  10. #10
    Advanced Tuner Justinjor's Avatar
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    Quote Originally Posted by IDRIVEAG8GT View Post
    This is an M6 Vette?
    Yes sir, M6

    Quote Originally Posted by Russ K View Post
    Seen that happen before when raising the Torque Management tables too high or maxing them. Just try raising them to more closely match the actual output of your engine.

    Also log Burst Knock, Launch-Advance and Torque Mgt Advance.

    Russ Kemp
    Burst knock is disabled
    TM has been disabled from the start.

    No other changes to the car between the original tune and the one in the OP.
    The timing and maf calib tables were touched and nothing else.

    Original tune attached

  11. #11
    Senior Tuner Russ K's Avatar
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    Your Torque Management tables need to be changed. Use this stock file to compare.

    Russ Kemp
    Attached Files Attached Files

  12. #12
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    I'm having this same problem with a 2001 Sierra I recently tuned. I logged torque management advance and nothing showed up.
    2012 Chevy Cruze A6 1LT RS

    Formerly - 2004 GTO, 2002 Z28, 2007 Colorado, 2008 Silverado

  13. #13
    Advanced Tuner Justinjor's Avatar
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    Thanks Russ. I'll take a look at that tonight. I didn't do the original tune but I'm not sure if I'm supposed to name names here or not.
    I do know the TM was turned off or disabled though.

  14. #14
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    i had a similar issue, I had to disable Spark Smoothing

  15. #15
    Advanced Tuner Justinjor's Avatar
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    I was thinking that as well Carl. I only had it enabled as I was trying to rid myself of some of the buck and surge associated with this cam.

    I'll see about disabling it and see if that makes it go away.

    How long is the 'learn' time for the ECU after you flash it?

  16. #16
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    Will check in on this later. I wont' be able to test torque management changes until Monday at the earliest.
    2012 Chevy Cruze A6 1LT RS

    Formerly - 2004 GTO, 2002 Z28, 2007 Colorado, 2008 Silverado

  17. #17
    Senior Tuner IDRIVEAG8GT's Avatar
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    I do believe M6 spark smoothing has something to do with this issue.
    Gray Ghost- The abomination. 2007 Chevrolet Silverado CCSB. 98mm turbo, nitrous, 428LSX, Rossler 80E with a brake. Finally finished. 23 psi, no numbers, Slow as hell.

    PBM G8- Aluminum 364, twin Precision 67/66 turbos, 6L90 trans swap, CTS-V/Vaporworx fuel system, slowly making progress.

    Dads 2011 CTS-V- Stock bottom end, stock heads, LS9 cam, pullies, ported blower, ported TB, D3 goodies, and lots of nitrous.
    618/618 motor
    906/862 spray

    Caterpillar 50 Forklift- Duramax swap

  18. #18
    Advanced Tuner Justinjor's Avatar
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    Removed spark smoothing and that seemed to significantly help the issue.

  19. #19
    Advanced Tuner Justinjor's Avatar
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    What was/is wrong with my torque management? The tuner who did the car said he just disabled it altogether and I was under the impression that was normal protocol. Is that incorrect?

  20. #20
    Senior Tuner IDRIVEAG8GT's Avatar
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    Quote Originally Posted by Justinjor View Post
    What was/is wrong with my torque management? The tuner who did the car said he just disabled it altogether and I was under the impression that was normal protocol. Is that incorrect?
    The torque management tables I try to leave semi operable so you driver error can be controlled to an extent and/or you don't end up breaking a bunch of shit.

    In essence, I typically will remove 75% Torque Management from these cars as it does make them more fun to drive.
    Gray Ghost- The abomination. 2007 Chevrolet Silverado CCSB. 98mm turbo, nitrous, 428LSX, Rossler 80E with a brake. Finally finished. 23 psi, no numbers, Slow as hell.

    PBM G8- Aluminum 364, twin Precision 67/66 turbos, 6L90 trans swap, CTS-V/Vaporworx fuel system, slowly making progress.

    Dads 2011 CTS-V- Stock bottom end, stock heads, LS9 cam, pullies, ported blower, ported TB, D3 goodies, and lots of nitrous.
    618/618 motor
    906/862 spray

    Caterpillar 50 Forklift- Duramax swap