I lock mine at 45mph also. I have a 5-second hysteresis programmed to extend the lockup speed during moderate throttle accelleration.

 

What programer are you using? If HPTuner were did you adjust hysteresis?

 

70mph at WOT, Depending on throttle 35 to 55 for cruising.

 

I control the 4L80-E with a TCI Trans Control Unit. It handles all transmission function with only TPS, RPM, and VSS as input. Neat unit. The factory PCM does not have a parameter for that that I know of, but you can choose different TCC lockup speeds for different gears. You can achieve a similar function as what I am doing by putting the lockup speed for third higher than your target lockup for fourth of 45mph for example. That way during moderate accelleration you won't get lockup until you hit fourth.

 

My tranny builder recommends no lock-up on WOT to save the converter clutch from slipage and burning-up. Any other opinions?

 

Buy a PI? Tune so that it doesn't lock at WOT is another.

 

What's a PI? Is that a triple plate clutch?

 

All the stock trucks lock at WOT from the factory, my truck is set at 85 mph for TCC engagment.

peace
Hog

 

Yes, Performance Industries Vigilante, 3 disk clutch. It's lockup is amazing. Feels like a gear shift when it locks. Even at WOT.

I think I am being conservative locking at 70MPH.

 

More line pressure and raise the min and max duty cycles of the TCC sol to 98. That is what I did on my 80e, not sure if it will help you out but you might want to check into it BEFORE YOU TRY IT of course.