Diablosport Forums

I have a 2000 GMC Sierra 5.3l auto and under full throttle the tranny shifts very hard. I turned the pressure on wide open throttle to -25% and also on part throttle. I also changed the shift time to 12% slower and when you drive around normally or part throttle it shifts very smooth. Every time when I go full throttle it starts to shift very hard, I thought that by changing the tune that this would help but it does not. In the post that I wrote about this problem you told me to send you my backup of my tune and you could fix it for me. I have added a cold air intake and cat back exhaust and I am running the 87 oct tune.
Mike I emailed you my tune and I was wondering if you got it?

U7198
rev 2.13

I'll check my emails when I get in the office tomorrow, and let you know if I got it.
Should have it back out to you tomorrow all fixed up.

Thanks