99DWPTA

iTrader: (10)

2-3 shift WOT bounces of limiter.. need tuning or??
1-2 shift is fine

z28241

iTrader: (13)

Did you do anything like a rear end gear swap?

FadedSS

iTrader: (15)

i have the same problem. i am pretty sure its because im untuned with a stall

silver-mod-o

iTrader: (15)

if you have added a looser converter or swapped to a shorter gear, or added shorter tires it plays games with the computer trying to shift the car.... you need to get it adjusted and get everything back in synch then it'll shift right again...

98Z28CobraKiller

iTrader: (17)

Your problem is that as you start making more power, your 4L60 proves to suck more and more. The shift is taking too long and causing you to get into the limiter. This can usually be resolved with tuning by lowering (fudging) the shift points and/or zeroing the MPH shift tables that are relavent.

performabuilt

iTrader: (25)

Its likley theres not enough time being allowed from comand to shift and yes as power is increased moe time will need to be allowed. While the PCM is instant the mechanics and hydraulics of a transmission are not they take a fixed amount of time to react, Power adding can affect his , Heres how: Lets say that it take .5 seconds to make the shift at WOT at a given power level and you increase that power level And the rate of RPM increases faster Then there may not be time to make the shift before you hit the limiter. So you will need to allow more time from comand to shift as power increases. This would be true of any trans not just the 4l60e and the 2-3 shift takes longer than any other shift to complete because its the most compliated shift more fluild going more places. So it would show the effect first. I have also noted this can be compounded even more so on a 2-3 shift both manually and in the D position because of the addition of the OVERUN CLUTCH coming on further increasing the time it takes for the shift to occur, Thats why you hear of people hiting the rev on the 2-3 shift even more often in D or maual yet have normal shifts in OD , I ussually say from comand to shift you should allow at least 400 to 500 rpm for the shift to complete of course with differrent power levels this would vary and would need to be played with till you get the ideal timing. But I think that provided the trans is in good shape many times when you hear of this issue this is the reason it happens failure to take into affect the time it takes mechanically to make the shift when doing the tune.
High stall converters also can substaintially increase this time.