Transmission shift point questions..
11-21-2009, 11:03 AM
#1
Transmission shift point questions.. I have hptuners.Still a bit cofused. If you have normal 4l60 car you can punch in your new gear change and tire height and let it auto figure out new shift points part throttle,full throttle, tcc lockup..etc.
So going say from 3.23 stock 4l60 to 3.73 gears would not be much of a big deal. But now what about if you change redline and wot shift point rpm.So now instead of stock you are say shifting at 6600 rpm versus say 6000 .Not sure my auto scaling takes rpm into account..don't seem to..does it?
I dont' think see any changes in the part throttle or full throttle mph tables when change out shift rpm points.
And what about effect of bigger stall like going from stock to 2800 or 3400 or even 3600 . I am not supposed to lock my stall past 30% throttle so would assume this is going to have an effect on my shift mph points as well due to slippage?
And to make things more confusing I got a 4l80 segment swap ,so that means the given shift points for part and full throttle in mph are based on truck with like 2.73 gears stock. So now if I auto change values which for some reason is not working right for me so having to input this stuff manually including speed correction then still the values calculated are maybe way out to launch as truck rpm limits are like 5000 and mine are like 6500 shift points 7000 redline.And car shift points are based on the 4l60 gear set in trans aren't they..which are like 3.08 first gear compared to my 4l80 2.48 first, 1.48 second. Don't these internal gear ratios affect the desired shift points in part and full throttle?
I have found f body gear calculator that can show what you can get in each gear and rpm ,guess it just would be off a bit depending on converter slippage.
So going say from 3.23 stock 4l60 to 3.73 gears would not be much of a big deal. But now what about if you change redline and wot shift point rpm.So now instead of stock you are say shifting at 6600 rpm versus say 6000 .Not sure my auto scaling takes rpm into account..don't seem to..does it?
I dont' think see any changes in the part throttle or full throttle mph tables when change out shift rpm points.
And what about effect of bigger stall like going from stock to 2800 or 3400 or even 3600 . I am not supposed to lock my stall past 30% throttle so would assume this is going to have an effect on my shift mph points as well due to slippage?
And to make things more confusing I got a 4l80 segment swap ,so that means the given shift points for part and full throttle in mph are based on truck with like 2.73 gears stock. So now if I auto change values which for some reason is not working right for me so having to input this stuff manually including speed correction then still the values calculated are maybe way out to launch as truck rpm limits are like 5000 and mine are like 6500 shift points 7000 redline.And car shift points are based on the 4l60 gear set in trans aren't they..which are like 3.08 first gear compared to my 4l80 2.48 first, 1.48 second. Don't these internal gear ratios affect the desired shift points in part and full throttle?
I have found f body gear calculator that can show what you can get in each gear and rpm ,guess it just would be off a bit depending on converter slippage.
11-21-2009, 12:12 PM
#2
I found I had to go in and tweak the part throttle settings. Running a 4L60E, 3600 stall and 3.42 gears. You have to make sure that the WOT settings and Part throttle numbers don't conflict causing the pcm to try and do two different things. Also you have to make sure the TCC isn't trying to lock at the same time as a shift is taking place. I just keep playing around with mine until I get it to shift how I want it.
