[updated:LAST EDITED ON 06-Aug-02 AT 09:46 AM (EST)]I was talking to a friend thats a motorhead, you know the type. He has 3 projects going on all at the same time. Anyway I was telling him that with my 89 Bronco, that unless you punched it from a stop light, that it is tough to really get it up to speed with the 302 and 3:55 gears. He said you know you could change the torque converter ( for a higher rpm) and that would give more power out of the hole. This is an area that I don't know jack about. Has anyone tried this or know what he's talking about?

 

A torque converter (t/c) acts like a clutch for the automaic transmission. It allows the engine to build up rpms before engaging the trans gears. Your stock t/c stall speed, the rpm the engine needs to achieve before the t/c locks and trans fully engages, is probably about 15-1600rpm.

Increasing the t/c stall speed to say 20-2500 rpm will allow the engine to build higher rpms before fully engaging the trans. That will improve your off the line performance, but nothing is free.

You'll have to R&R your trans, have your t/c rebuilt to a higher stall speed or buy a new one. The big issue is cruising speeds. If you have a AOD, what rpms does it use at 65mph? Probably around 1800. If the cruising rpm is below your stall speed, your t/c won't be locked and you'll have slippage which results in inefficiency (poor gas mileage) and excessive heat.

For a stock small block, lower gearing (higher numerically)would be far more effective in improving your bottom end performance.

 

Very informative. Thanks for the post.