1998 GMC Sierra K1500 5.7/4L80E, longtubes, 411 w/COS 5, marine cam/intake, Whipple. 91 octane at 6000'.
1997 GMC Sierra K3500 7.4/4L80E, 411 w/COS 3, Whipple, small cam.
2004 Corvette Z06 with longtubes.
well I tried the spreadsheet values I made following this and it made the trans very busy.. Probably due to the 3.42 gears and the 4L80E's steep gearing with the 78mm turbo on the 5.3 (Read: Lag) that I have to really get into the throttle to get her going and the trans constantly shifts and TCC locks/unlocks, etc. Copied the 4L60E tune shift points that I remember to be a nice mix of performance like feel and drive-ability on this trans. Will still keep playing around.
Last edited by Mean Green Z28; July 26th, 2017 at 08:07 AM.
Move the sloped part of the shift curves to a higher TPS%.