Converter lock up Q
10-09-2020, 12:49 PM
#1
Converter lock up Q I have got some "sputtering" while going up a consistent hill in 4th gear while the converter is locked. This only happens while cruising at ~60mph, light throttle, and low RPM. I can get it to stop if I lift the throttle and depress it again as it kicks the converter out of lock up and the RPM's pick up. Other than this condition, which I can repeat on my daily drive to get coffee, there are no other issues and no mil.
I have reviewed my setting in HP Tuners and I'm thinking I should lower the 4th gear RELEASE by a few MPH for the values under 50% TPS.
Am I thinking about this right? Also, What should I log in the scanner which helps me sort out this and figure out if there are other areas of trans tuning I should get after?
Currently I have pretty much stock tranny settings with a few minor tweeks from a 2005 Chevy Express which had a 4.8/4L80E combo. Which is what I'm running now with the exception of adding a cam (~230 dur and 585 lift squared), Inj, and a turbo, oh and the tranny is a Hughes performance unit so I believe I don't need to mess with line pressures. My thought is that the cam impacted the bottom end torque and the engine is stumbling under lockup/load so I want to unlock the converter earlier to maintain RPM/Power band.
I have enclosed my tune.
I have reviewed my setting in HP Tuners and I'm thinking I should lower the 4th gear RELEASE by a few MPH for the values under 50% TPS.
Am I thinking about this right? Also, What should I log in the scanner which helps me sort out this and figure out if there are other areas of trans tuning I should get after?
Currently I have pretty much stock tranny settings with a few minor tweeks from a 2005 Chevy Express which had a 4.8/4L80E combo. Which is what I'm running now with the exception of adding a cam (~230 dur and 585 lift squared), Inj, and a turbo, oh and the tranny is a Hughes performance unit so I believe I don't need to mess with line pressures. My thought is that the cam impacted the bottom end torque and the engine is stumbling under lockup/load so I want to unlock the converter earlier to maintain RPM/Power band.
I have enclosed my tune.
10-11-2020, 09:03 AM
#3
Check out the link below. Especially the TCC apply/release tips. It addresses your issue. You might have to add 2 mph at a time to lockup dependent on the cam until it drives smoothly without hunting/bucking or shudder.
https://ls1tech.com/forums/automatic...tm-w-pics.html
This link too. One chapter is devoted to Transmission Tuning the 4l60e and the 80. It explains how shift speeds (shift speed vs TPS ) have to be adjusted to compensate for mild cam changes and/or converter changes. The 4l65E table with adjustments where throttle position/RPM is mostly above 1700 RPM is a good starting point.
http://www.masterenginetuner.com/
https://ls1tech.com/forums/automatic...tm-w-pics.html
This link too. One chapter is devoted to Transmission Tuning the 4l60e and the 80. It explains how shift speeds (shift speed vs TPS ) have to be adjusted to compensate for mild cam changes and/or converter changes. The 4l65E table with adjustments where throttle position/RPM is mostly above 1700 RPM is a good starting point.
http://www.masterenginetuner.com/
Last edited by dlandsvZ28; 10-11-2020 at 09:31 AM. Reason: edit content