The truck is a 08 Sierra 1500 2wd 5.3 4l60e stock. I tuned it yesterday and went test drive it everthing went well, but I will not shift a full throttle from 1st to 2nd, it feels like a it's a fuel cut off but I cannot find anything that would cause this. Shifts are set at 5900. This is the first 07+ truck that I tune so I could be missing something. Also at full throttle the truck only shows 83-84% tps in the scanner.
Any help is appreciated.
here is the tune
If its acting like it hits the limiter, check your speed on the log at the time it starts hitting the limiter. Your shift speed is off and needs to be adjusted.Originally Posted by cdythms
99 T/A WS6, original LS1 turbo
What's the rev limiter set at?
i dont know why, but it wouldnt let me post the tune, it just stays saying uploading.
the rev limiter was set at 5950 and as far as i know all the rev limiters fuel cut offs and whatnot were at atleast 6300.
I went ahead and started my tune from scratch and put the shift points at 5800 and it shifts like it should. one question, what takes priority the shift speed at full throttle(mph) or the shift rpm at full throttle?
Whichever comes first, although its best to have them at the same speed. You need to raise the rev limiter. It takes time for it to shift and the rpm will rise. If you are commanding a 5900rpm shift it might not actually happen until 6050rpm.
The RPM and MPH have to match, if one is off the truck will act like you described. There's a spread sheet that someone created, I use it to get close and then fine tune the MPH from there if needed. I've attached a copy if you'd like to use it.
99 T/A WS6, original LS1 turbo
On my 08 Silverado V-max, i have my rev-limiter set at 6500RPM and trans WOT shifts set at 6150RPM (1-2) Shifts pretty good...
I usually use the rule of thumb of 2 mph per 100 rpm increments that you increase. IE.- if its at 5500 factory shift pt and you go to 6000 1-2 shift then add 10 mph and so on. always works for me it will also depend on gear and tire size but 2 mph should get you close enough to the window hope it helps man
I didnt update this, but everything is working as it should. Thanks for the responses.
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