anyone with a GM 6L80 (preferably a 6.2 with 3.42 gears) tune their WOT shift points based on mph instead of rpm? If so, what speeds did you use in each gear? And what rpm did that correspond to?

 

stock 6.2, about 6300 rpm.

 

What I am looking for is the mph for each gear at WOT shift in that rpm range of 6,000 - 6300 rpm.

 

you will need to data log it, or find a calculator.

why do you want to use mph?

 

I'm using Diablosport In-Tune. 2014 Sierra 6.2. For some reason, when I set WOT shift points with rpm in the 6200 range, it does not like it. It stops pulling before reaching the set point - shifts - then picks back up. Also tried raising the rev limit to make sure that was not the problem. Lew recommends setting the shift points based on speed instead of rpm. So we'll give that a try. I'll have to go out this weekend and data log it. 1st, 2nd, and 3rd are the most important to dial in. I don't have a good place to get WOT shifts for 4th and 5th without chancing a long conversation with D'man.

 

Use the calculator on Randy's page....

 

where is it located?

 

Randy's ring and pinion.

 

did some data logging in case anyone else needs the same info.

2014 GMC Sierra, 6.2 with 3.42's with factory 20" wheels. My desired WOT shift points for optimal 1/4 mile or 0-100 mph:

1st 6200 rpm = 41 mph
2nd 6100 rpm = 69 mph
3rd 6100 rpm = 107 mph
4th 6000 rpm = ? didn't go that fast.
5th 6000 rpm = ?