EGS53 NAG1 TCC Lockup

[scubasteve231]

I have a 2007 Chrysler 300C with 5.7L engine and NAG1 trans. I am considering buying HP Tuners, hoping to make some adjustments to the factory TCM calibration that hasn't aged well with the transmission.

At low speeds around 30-45 MPH, and especially when decelerating to a stop, I feel some shuddering/vibration that is from the torque converter clutch not applying/releasing/slipping as smoothly as it did when new. When coming to a stop, if I bump the shifter into manual mode, the shuddering stops immediately. Driving around in manual mode, the transmission operates really well with no issues. For that reason, I believe some tuning could extend the useful life of the transmission and make the car much nicer to drive.

What I would like to do is change the tuning such that the torque converter clutch will only apply in 4th and 5th gear, at speeds above 50 MPH, at light cruising loads or pedal positions. Is this possible with the parameters that are available?

After a lot of searching I came across the attached HPT file for a EGS53 TCM, and I loaded it up in the VCM Editor just to preview it and see what parameters were available. However, what I see are a lot of general options, but not many tables that can be edited. It looks I could I could possibly change the TCC Pattern for Normal Mode to Sport, which is the same setting for Autostick mode. Based on how it feels when in Autostick mode, I'm guessing that may get me what I want but I'd like to confirm first. Other than that, it doesn't seem possible to change the specific conditions of when the TCC will apply, unless I am missing something?


Screenshot 2023-04-09 181307.pngMTCM_P5153854AB_306Gears-287tires-Backup.hpt

[jefo]

You can easily disable lockup by gear (Raise apply rpm to the max in the Apply/Release tab), and could back calculate the rpm from the gear ratio to apply for the 50mph mark. Though an unlocked converter creates more heat, and you should change the fluid and filter first.

[DodgeBoy_8HP]

I have a different opnion:
- Yes, it is possible to change how your LCC open/closes
- Yes, you could change back and forth between the two modes you mentioned, but these changes have to happen with other updates
- I would not recommend having LCC/Torque Converter open in high gears (3rd, 4th and 5th)

In case you need support, let me know.

Thanks.
DodgeBoy.
YouTube: https://www.youtube.com/@dodgeboy2785

[scubasteve231]

You can easily disable lockup by gear (Raise apply rpm to the max in the Apply/Release tab), and could back calculate the rpm from the gear ratio to apply for the 50mph mark. Though an unlocked converter creates more heat, and you should change the fluid and filter first.

Thank you! I saw those tables but they didn't make sense to me at a first glance, probably because they use the output shaft RPM. You have a good point about the heat. It looks like the stock calibration has the lockup working in every gear, and it's possible the factory fluid cooler might not have the capacity to deal with the extra heat of a non-locked converter. Might be best to disable lockup in 1 and 2 first and monitor the fluid temperature.

It looks like I will be purchasing HP Tuners after all, and I'd say that they owe jefo a sales commission reward for helping me confirm that the software could do everything I wanted.

[Jpe61]

If the output shaft RPMs don't make sense, I think there is a calculator for those somewhere in here... I have one and I think I downloaded it from HP-tuners site.