I have a Pacbrake and an ATS torque convertor controler in the new truck. Im just curious, what should I program the torque converter to lock at? High or low speeds? What exactly will it do? Thanks

 

Usually, lock at around 30mph or so, unlock at 25mph.

You don't want it to lock at low rpm's because it can damage the transmission. Above 1200rpm is best from what I heard.
Having it locked will lower trans temps, help towing. I have a manual switch for mine.

 

same, i have a manual switch and use it everytime i drive (as long as i'm not in the towing tune since that tune has AMAZING shift points/lockup points) i lock mine up whenever i hit 28-30mph and keep it locked until i'm below 25... lugging it with it locked at under ~1100-1200 rpms is bad news bears (lol) and the torque coupled with low line pressures can/will do serious damage to your trans/converter

 

I don't use mine driving it town because of all the stop and go and constant stopping. I was thinking about buying one of the programable modules to control the TC lock automatically, but I'm swapping in a ZF5 next year anyways.