Blue02z28

torque converter Locked VS. unlocked... what is the general rule of thumb in horsepower difference? how many horses can you expect to add to a dyno if the converter is unlocked?

BriancWS6

iTrader: (18)

You won't "add" any horses unlocked. The locked method get's you the highest hp #s. As far as a general rule of thumb goes, I don't know. But here are some #s I know of. A buddy of mine with a 4400 stall went high 420s-low 430s locked and like 403-406 unlocked. My car went 363 unlocked and 369 locked through a TCI SSF3500. The size of the converter and its efficency has a lot to do with the difference in the locked vs. unlocked #s. But don't let that bother you, cause the hp lost unlocked with a bigger stall will more than be made up at the track when it comes to your ET.

GPel

Thats correct, there is a loss w/ stall converters on any dyno. The best converters only have a 98% true lockup or one to one ratio.