Over the summer, I bought a Pro-Built street/strip TH700 and an ACT 9.5" 2400 torque converter. When I powerbrake, I can usually only get it up to about 2000 or 2100 RPM before it feels like it wants to move. I never pushed it further, because I didn't want to cause any damage to the tranny or converter.

Does this sound right? Am I powerbraking the wrong way? What's it supposed to feel like?

 

I'm not sure powerbraking will put the converter at its maximum stall. I talked w/ ACT some time ago and they said that the converters are usually within 100 RPM of the desired stall range, so it might actually be a 2300 stall (which is no big deal). So if your getting 2100 out of a converter that might be stalling at 2300, sounds like there is no problem. Don't forget that engine torque will effect stall speed as well. The more power you have at the flywheel, the closer to the stall rating you will acheive.

 

Power-braking will never fully stall out a converter.

 

Thanks guys, it makes sense now.

 

The converter rating is only an estimate. A 2400 stall converter hooked to a 350 SBC may stall at 2000. The same converter behind a 454 may stall at 2600.

The only way to know the true stall of a converter is with a transbrake. The transmission is locked in 2 gears and no power is transfered out to the driveshaft. This allows the engine to climb in rpm until the converter "stalls". The vehicle's brakes can never hold a car back to it's full stall because of torque multiplication. The engine will quickly overpower the brakes before the converter reaches it's full stall.

 

hey blue86iroc are you using a tranny cooler at all? if so what type..

 

Yep, a B&M SuperCooler. I lost my stock tranny due to heat and I surely didn't want that to happen to my new one.

 

Some guy online has a nova and a stall similar to that. He says that the warmer the tranny gets the higher the stall. This kinda makes sense, because as the transmission fluid gets hotter, its loses its viscosity (if that means it gets more watery). That would increase the stall, right? Which leads to another question...do converter companies rate the stall with warm, cold, or in between transmission fluid? I could of course be talkin outta my *** too tho.
Matt