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Thread: 6l80 won't go into 6th gear above 75mph or so in tap shift mode

  1. #1
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    Default 6l80 won't go into 6th gear above 75mph or so in tap shift mode

    I have two 6l80s setup with a 2009 corvette OS/tune and setup for tap shifting. gears 1-5 work fine but the transmission won't go into 6th gear via tap shifting over 75mph. We have already adjusted the TU/TD table to not safety shift up or down until you hit a super high mph or a super low mph respectively to allow more complete manual control(off road race buggy not a car)

    but is there some other safety shift table we can't access that is still locking out 6th gear from tap shifting at some point? certainly the normal shift tables allow for sixth gear at much higher speeds.

    Thanks!

  2. #2
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    Could these settings in the WOT shift speed and WOT shift RPM tables be causing problems?

  3. #3
    Lifetime Member Tre-Cool's Avatar
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    no. those settings ownt. attach your tcm tune here as its abound to be something else.

  4. #4
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    2009_Vette_5.ctd Here is the latest version of our tune. I think the VSS and gear settings may be off but the folks working locally on this in Kansas say the speed from the buggy and the gps speed matched up with these settings. The buggy has 40" tires and 5.40 gears and then the tcase is in 2:1 low range. in the main TU/TD table they put the forced up shifts to the max of 318mph and the forced downshifts to 5mph so they get the closest to full manual control. but even with this the trans won't go into 6th gear above 75 mph.

    Thanks for looking!

  5. #5
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    Not sure if you figured out prob yet, but I saw your WOT gear upshift and downshift speeds weren't matching up correctly. Made adjustments that should work.
    Attached Files Attached Files
    Last edited by TBMSport; February 10th, 2012 at 07:13 PM.
    Trailblazer "RS" 5.3L 6L80 4x4 & '07 TBSS LS2 6L90 AWD

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