WOT Upshifting

[jpowel29]

Comparing the time stamp information from EFI data logs, rpm (to determine where each shift is happening during the pass), and the time/speed incrementals from my time slips here is where my WOT upshifts occur (approximately):

1-2 Upshift at 1.6 sec (60' time = 1.97sec)
2-3 Upshift at 3.2 sec
3-4 Upshift at 4.6 sec (1/8th at 5.05 sec @ 97mph)
4-5 Upshift at 8.5 sec (1000' at 9.79 sec)
I see that I lifted around 1270' (1/4 at 11.66 @ 119mph)

I leave the line pretty soft in first gear, hit second before I hit 60', make third gear at 170', fourth gear at 300' and fifth at 815'. I upshift at 4150rpm and run a 31" tall slick with 3.73 gears. I know I can make up a lot of time to 60' and will be getting a better converter to help make that happen.

My converter looks to be fully locking (based on Trans Input/Output speeds showing equal and negative numbers on my TCC Slip rpm).

My question is what would be the benefit of extending the upshifts earlier in the run?

My WOT upshift speeds in my TCM are:
1-2 = just under 20mph
2-3 = around 40mph
3-4 = around 55mph
4-5 = around 86 mph

Any thoughts??

 

[Dozerboy]

Most seem to say it helps to get out of first sooner. I've seen just the opposite, but I'm only running a tow tune. 2nd gear launches might work real good for you.

 

[S Phinney]

Getting into the higher gears sooner will help build higher boost sooner and should maintain a stronger boost. This will allow your motor work a little more. I have been experimenting some with this and tranny tuning. It does help.

 

[jpowel29]

I am thinking about extending the 2-3 & 3-4 upshifts.

 

[JoshH]

Being a 2wd, I would guess you would see a benefit from the 2nd gear start. You could leave with more boost, and you would be less likely to blow off the tires on the launch or the 1-2 shift (since it won't happen).