I have heard this many times and I still do not know if it is true or not. I always hear people say putting a higher stall converter in your car eventually hurts your transmission and drivetrain because you are launching at a higher rpm so more stress is put on the car. Is there any truth to this?

 

not really, cause it's not jolting the drivetrain like a manual would.....but it also depends on the setup and combination you have.....if you have a 305 let say, with 2.73 rear gears...and you put a 3500rpm or so stall in it...it probably will burn the transmission out of it...convertors are good...if you have the right combo

 

As with most things, it depends. Examples are easier if using extremes, so here I go. If you have a stock, 100,000-mile '83 700R-4 that spent it's entire life behing an LG$, with 3.23:1 rear, and grandma driving, then suddenly you install a 383 with RV-type cam, Vortec heads, and a 4000 stall converter and drag slicks, then yes, you'll destroy the trans in no time. At the other extreme, if you have a fresh BTO Level 3 700R-4, a stock LG4, and you decide to upgrade from a stock 1500 stall to a 2000 stall, then No, it won't have any effect at all. Of course, driving style can affect life expectancy in my first example. And neither of these examples is your car.

 

The converter stall allows the engine rpm to quickly get into the powerband. For street or street/strip, you want a converter that stalls about 500 rpm into the operating range of the camshaft. For full race, it's about 1000 rpm.

The converter in my race car stalls at 6000 rpm. I can put the transmission in gear and drive around the pits at 2000 rpm or less. Driving around at part throttle like this means the converter has a lot of slip. This slippage creates heat and heat kills transmissions. Using any converter higher than a stock stall requires an aftermarket cooler to help remove the excess heat.

If I put the throttle to the floor, the rpms will jump to 6000 and won't go below that until I let off the throttle. Actually I shift at 7400 and the rpm only drops to 6400.

Putting in too high of a stall is worse than not enough stall.