I have a vig 3200, and everyone says with my charger and mods it should be stalling around 3800-4000rpm's
How do I verify what it stalls at?

I tried to power brake it and check the rpm when it moves and it moves at 2500rpm!

 

you are confusing your stall speeds. the rated stall of the converter behind a mild LS1 is 3800rpm. with your ATI youd see 4200+. Now, what you foot brake it to is dependany upon gear and tire. Testing stall speed is usually done in 3rd gear (1:1) vs. you foot stalling it (brake stalling it) in 1st (3.06:1). Also, if yo tires aint sticky you WONT be holding 2500+rpm. i can stall mine to about 2500 on the street on Goodyears (Vigi3200 here).

You're fine.

 

Terry you need to have the tranny in second gear. The converter will flash to 4000-4200 with the blower. I spoke with PI yesterday about it. By the my tranny took out my converter also. PI rebuilt the Vig for $290.00 I had some parts that got welded together. It ended up being a pretty costly shift kit...

 

From the Yank FAQs section, the difference between brake stall and flash stall:

Flash stall is the maximum your engine's torque can stall a torque converter. In essence flash stall and full stall are nearly identical. If you had a transbrake, you could find full stall by putting your foot to the floor and reading your tach. For argument sake, let's say we're testing a 3500 stall Yank ST 3500. If you had a transbrake, you would see around 3500 rpms. If your motor was at idle and then you suddenly floored the throttle, you might see slightly more (maybe 100 rpm more) stall for a half second as the momentum of the motor's internals "flashed" the converter a small bit above its true stall rating.

Brake stall, on the other hand is a very subjective thing. For most, it's the highest stall you can achieve before your tires spin. This varies greatly based on many factors: Traction, gearing, brake clamping force, and engine torque. With a ST3500, I may only be able to get 2200rpm "brake stall" on the street with street tires...any higher rpm and the motor torque would overwhelm the tires. But if I was at the track with racing slicks on the starting line, I might be able to get 3200 brake stall before the motor torque overwhelmed the tires. See...brake stall is very subjective.

Yank rates their converters based on their intended application. A ST 3500 will stall 3500 rpms in a stock LS1. If you had a 422 and wanted a ST 3500, the converter you received would still stall 3500 because it would be built around the torque of a 422, not a stock displacement LS1. Yank checks the stall of their converters and their competitors by using either a trasmission dyno or a "tranny tricker" in the vehicle tested. With the tranny tricker, you can place the vehicle in 2nd or 3rd gear and stab the throttle to the floor...making it easy to read both flash stall and full stall.

 

Good info Patrick!