I had my th350 rebuilt last spring with what is supposed to be a gm converter with a 2400-2600 stall speed. The guy who built it, referred to it as a "corvette" converter.

Problem is that the converter will not stall above 1200 rpms without breaking the rear tires loose (275/50/r15 drag radials). It doesn't seem any better than my stock one. I'm pretty sure it IS different though, because when i get on it with street tires in first gear, I melt the tires. That didn't happen with the other converter.

What could be the cause of this? My car weighs about 3,000lbs with me in it, and has 4.10 gears. The builder also reccomended I run type F fluid, which I do.

Thanks for any help you can give.

 

Is my car just too light for the converter? Since most likely it was made to stall a car with lower (numericly) gears and one that weighed 6-800lbs more?

 

You've just got a convertor that's a little tight on the low side is all. Dont judge anything by the "power brake" for stall speed, that does nothing. For a better idea of true stall speed: this only works with cars that wont do the passing gear thing-get in high gear and run about 10mph or so, then mash it. Note where the tach goes at the first hit, this will be close to your convertors actual stall.

Not only that, you've got a light car, descent hp, and alot of gear so it's not gonna take much for you to overpower the tires on the street/driveway powerbraking. Since your foot braking-unless you jumped upto a t-brake, that tighter convertor will help your cause since the car will react quicker than if it was looser and the car had to "make a run at the convertor"

Different convertors will act differently based on the combination of your car. I can only "powerbrake" my car to about 3800, but it flashes at 5100 on the hit.