TC unlocks when moderate throttle applied while cruising on the highway?
01-08-2005, 05:46 PM
#1
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TC unlocks when moderate throttle applied while cruising on the highway? When I give a decent amount of throttle (like 1/3-1/2, not enough to kick down into 3rd) the TC seems to unlock (RPMs jump up a bit for a second) then locks again (rpms drop and hold). Very annoying. I'm getting a tune soon, can they do something to tune this out? Like change what speed the TC locks at or anything? Stock converter, other mods in sig.
01-08-2005, 05:59 PM
#2
Yes it can be tuned. I tuned my converter lock up with HP Tuners. There is a lock up versus TPS% versus MPH scale for both lock and unlock.
I tried tuning mine to hold lockup with more throttle but it made the engine ping and it had some knock retard.
I had to customize it just enough to where it wasn't annoying and didn't ping.
Be sure you go on a good test drive after it's tuned. Maybe have them tune lock up out of third.
Another problem I had was when it shifted to third the tcc would lock up, then when it commands a 4th gear shift the tcc unlocks, it shifts, then it locks back up.
My car is a 2002 SS with 3.23's and a transgo shift kit.
I tried tuning mine to hold lockup with more throttle but it made the engine ping and it had some knock retard.
I had to customize it just enough to where it wasn't annoying and didn't ping.
Be sure you go on a good test drive after it's tuned. Maybe have them tune lock up out of third.
Another problem I had was when it shifted to third the tcc would lock up, then when it commands a 4th gear shift the tcc unlocks, it shifts, then it locks back up.
My car is a 2002 SS with 3.23's and a transgo shift kit.
01-08-2005, 06:05 PM
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Originally Posted by jxaxsxoxn
Yes it can be tuned. I tuned my converter lock up with HP Tuners. There is a lock up versus TPS% versus MPH scale for both lock and unlock.
I tried tuning mine to hold lockup with more throttle but it made the engine ping and it had some knock retard.
I had to customize it just enough to where it wasn't annoying and didn't ping.
Be sure you go on a good test drive after it's tuned. Maybe have them tune lock up out of third.
Another problem I had was when it shifted to third the tcc would lock up, then when it commands a 4th gear shift the tcc unlocks, it shifts, then it locks back up.
My car is a 2002 SS with 3.23's and a transgo shift kit.
I tried tuning mine to hold lockup with more throttle but it made the engine ping and it had some knock retard.
I had to customize it just enough to where it wasn't annoying and didn't ping.
Be sure you go on a good test drive after it's tuned. Maybe have them tune lock up out of third.
Another problem I had was when it shifted to third the tcc would lock up, then when it commands a 4th gear shift the tcc unlocks, it shifts, then it locks back up.
My car is a 2002 SS with 3.23's and a transgo shift kit.
01-08-2005, 06:20 PM
#5
Originally Posted by anestech*
My tuner is using HP Tuners, and it will be done on the dyno. Why would I want lock up tuned out of 3rd, just so I doesn't have to unlock when shifting into 4th? That isn't really a problem, just the unlocking while IN 4th and not kicking back down to 3rd.
I guess if you don't get a shift kit you won't need to disable lock up in third.
The problem is after the shift kit the tcc apply is more firm.
When it's in third and locked up it's fine, then when it commands a fourth gear shift it unlocks, shifts and locks. It feels like the trans is popping out of gear and going back in because the rpm goes up, then it shifts, goes down, locks up again and goes down more.
Basically there is an rpm flare.
The reason it unlocks during the shift I would guess is so it doesn't put strain on the torque converter clutch damper springs.
01-08-2005, 06:42 PM
#6
Here is my lock up chart. To disable lock up you just put in a high number that it will never see.
The green numbers are the stock tune numbers and I think this is whats in my car now.
any number on this chart can be changed to suit your application or preference.