4L80E Transmission tuning question
03-05-2008, 10:11 AM
#11
I had the same issue after my 4L80E install. I ended up lowering the shift RPM continually until it got to the general area where I wanted it. I think my 1-2 shift RPM is 5200 (shifts at about 5900), 2-3 is 5500 (shifts at 5800). Something like that anyway. I have never been able to figure out why this is.
03-05-2008, 10:11 AM
#12
TECH Veteran
Yes, EFI.
No, Have not bothered them ...yet
I was working the issue when I got orders to Iraq and left 4 days later
I will be back in 40.33 days/967.98 hours. Not that I'm counting
I dont have my laptop with me but I remember lowering the 100%TPS table. I will have to grab my laptop tomorrow, I could even load the tune for you. You an EFI user?
No, Have not bothered them ...yet
I was working the issue when I got orders to Iraq and left 4 days later
I will be back in 40.33 days/967.98 hours. Not that I'm counting
I dont have my laptop with me but I remember lowering the 100%TPS table. I will have to grab my laptop tomorrow, I could even load the tune for you. You an EFI user?
As far as your 40.33 days.... did you account for a wake-up? I seem to remember when I was in the military that times were always given in XXX days...and a wake up!
03-05-2008, 10:49 AM
#16
I know the feeling, the transmission tuning IMO is one of the least exact parameters you can adjust... But basically I do the opposite of you, I lowered my MPH and dialed in the RPM part of the shift point... I believe all three conditions have to be met in order for the tranny to shift... I will say after I installed my shift kit, I did not have to have soo much fudge room... Granted I have an 60e, but I think the logic is the same...
03-05-2008, 10:57 AM
#18
I know the feeling, the transmission tuning IMO is one of the least exact parameters you can adjust... But basically I do the opposite of you, I lowered my MPH and dialed in the RPM part of the shift point... I believe all three conditions have to be met in order for the tranny to shift... I will say after I installed my shift kit, I did not have to have soo much fudge room... Granted I have an 60e, but I think the logic is the same...
03-05-2008, 11:18 AM
#19
Man! I got alot of reponse on this one
I will write this down and grab my laptop and look. What tables exactly were you wanting me to adjust in the tune? ie...B0101, D0309 etc....(made those up)
I did include the "wake up" in my calcs
It's not really accurate anyway because I will quit being productive at least a week before I leave!
Lol @ remote tuning. I am.
I already have the GTO tune built for the gear swap and timing adjusted for the N2O.
I'm trying to get the Tahoe squared away so I can beat the crap out of both of them when I get back. They have been off duty since October 07.
Thanks for all the help so far!
I will write this down and grab my laptop and look. What tables exactly were you wanting me to adjust in the tune? ie...B0101, D0309 etc....(made those up)
I did include the "wake up" in my calcs
It's not really accurate anyway because I will quit being productive at least a week before I leave!Lol @ remote tuning. I am.
I already have the GTO tune built for the gear swap and timing adjusted for the N2O.I'm trying to get the Tahoe squared away so I can beat the crap out of both of them when I get back. They have been off duty since October 07.
Thanks for all the help so far!
03-05-2008, 11:42 AM
#20
Couple of things I see here, although not necessarily the cause of your problem.
2-1 downshift speed is higher than upshift speed. Upshift speed should always be higher, or the shift will not be commanded until after the downshift speed has been met as well.
Might try setting D0913 to 35-37mph, see if that has any effect.
2-1 downshift speed is higher than upshift speed. Upshift speed should always be higher, or the shift will not be commanded until after the downshift speed has been met as well.
Might try setting D0913 to 35-37mph, see if that has any effect.