I have an 02 Trans Am, 4L60E (stage 3), 3.23 gears, LS6 with a Tick Performance SNS Stage 2 cam, headers, cat delete, and ported heads by Katech.
I am having an issue where at 0% tps, and at around 45mph, the car feels like it is lurching back and forth...best analogy I have is that it feels like a manual trans would if you kept putting in and letting out the clutch at speed really fast. I have done a lot of reading and I *think* it has to do with TCC lock/unlock, but don't know much about it (I am a total noob to HPT). It has a 3800 Circle D single disk torque converter in it.
Here is my current tune...anyone care to look at it and point out what might be the issue (and any other glaring issues that should be changed)? Looking for good street manners except when really getting on the throttle for fun.
looking at you shift schedule/lockup schedule , under light or no throttle would end up locked up in 4th. and your analogy is close, when in lockup there is no buffer from converter, just like a manual car with clutch out.
So your tables show that the converter releases at 45mph/0%tps.
What happens if you just barely touch the brakes (just enough to send a brake signal and unlock the converter) at say, 47 during?
Does it still shutter at 45? or immediately at 47 when the brake signal causes the release?
I think most with much stall run Trans>Torque Converter>General>TCC Duty Cycle Minimum at about 90%. Maybe I am wrong on this but with much stall I prefer it locked or not locked. While with a low stall, the difference between locked and unlocked may be a small split (amount of slippage if only applied 20%), a higher stall will be much harder on the clutch if only engaged 20% or so. If it happens that the clutch material in your converter cannot take that much slippage...
Also, your Trans>Torque Converter>Apply/release>Minimum Throttle Release/Low Speed VSS setting (256) is causing it to always be in Low Speed VSS mode. Then your Low Speed TPS Lo and High are 0% while most run the Low Speed TPS Lo and High at 2%. At 0%, any tiny jiggle of the tps will toggle you in and out of that. I would probably set those back to 2%. I am not totally sure what exactly changes in Torque Converter release character between Low Speed VSS mode and High Speed VSS mode. Maybe in High Speed VSS mode the converter releases completely very quickly while Low Speed VSS mode is more gradual, possibly too gradual for your converter? I am curious what would happen if you move Low Speed VSS mode to 1mph or so and High Speed VSS mode to 2mph. This would force it to be in High Speed VSS release mode during any releases... Maybe this could help it release more immediately? Not sure.
Thanks for the replies guys, I really appreciate it!!!
If I even lightly touch the brakes or touch the gas, everything is fine...its only when I am coasting with my foot off the gas pedal. I will take a look at that and maybe try it out...
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