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Thread: Stock Auto Tranny Downshift adjustments

  1. #1
    Lifetime Member emarkay's Avatar
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    Question Stock Auto Tranny Downshift adjustments

    With gas being over $3.00 a gallon now and going up, I want to mod my downshift points. I know I could 'figger' it out, but can anyone point me directly to the tables and some rough settings?

    I want to keep part throttle downshifts exactly as is (stock) but I want to prevent "passing gear" (showing my age) (the 4-3-2 downshift) from happening until 90% throttle or above, at any RPM/MPH.

    Maybe also want to modify 4-3 and 3-2 to downshift a bit higher in the RPM band, but that is MUCH lower priority.

    These engines have gobs of torque and I hate that the stock calibration puts passing gear at about 60% throttle (SOTP estimate).

    I know it may cause some traction issues, but I do have traction control "on" and Torque management still enabled.

    Thanks!
    Early EFILive V5 user - Upgraded from AutoTap for DOS!
    2000 Chevrolet Camaro Z28, A4 - For occasional day trips...
    1984 Chevrolet Caprice Classic - For the family...
    1989 Honda VTR250 - For me and me only...

  2. #2
    Lifetime Member SSpdDmon's Avatar
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    It'll feel weird, but if you want to do it....just reduce the part throttle downshift tables (all cells except the last two). Look at the 2>1 shift for example. In stock form, it will not downshift into the lower gear (1st) unless you are under 10 mph or you give it 100% throttle. Just my opinion....

  3. #3
    Joe (Moderator) joecar's Avatar
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    Make sure D0960, D0961, D0962 are set to 100%.

  4. #4
    Lifetime Member emarkay's Avatar
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    Why it will feel wierd? I spent 7 years with a 1965 Impala... 2 speed powerslide....

    Just want to make it REALLY mean it when I floor it...
    Early EFILive V5 user - Upgraded from AutoTap for DOS!
    2000 Chevrolet Camaro Z28, A4 - For occasional day trips...
    1984 Chevrolet Caprice Classic - For the family...
    1989 Honda VTR250 - For me and me only...

  5. #5
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    I do that for all my customers with auto boxes. The kickdown everytime you give it a sniff of gas is annoying as hell.
    \"You Can Never Have Enough Horsepower\"

  6. #6
    Lifetime Member emarkay's Avatar
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    Quote Originally Posted by caver
    I do that for all my customers with auto boxes. The kickdown everytime you give it a sniff of gas is annoying as hell.

    So you agree with the above info? If not PM or email any differences, if you don't want to leak a 'trade secret' I'll keep it under my hat (hood/bonnet)
    Early EFILive V5 user - Upgraded from AutoTap for DOS!
    2000 Chevrolet Camaro Z28, A4 - For occasional day trips...
    1984 Chevrolet Caprice Classic - For the family...
    1989 Honda VTR250 - For me and me only...

  7. #7
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    No trade secrets I just change the throttle based downshift tables to near 100% in normal mode.
    Performance mode I leave the kickdown alone and move the rpm based upshift point closer to the rev limiter and reduce the torque reduction by 50%.
    The idea is normal mode is less frenetic and performance mode is there for when things get serious
    \"You Can Never Have Enough Horsepower\"

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