Well, my truck only put 236 HP to the ground with my stock auto transmission at 111,000 miles. The tech said I could probably get another 20 or 30 HP out of it if the torque convertor would stay locked up. What happens is the throttle gets to a certain position and engages the transmission kickdown feature, which unlocks the TC.
Anyway, I figured I was between 200 and 250 hp, so I wasn't far off. I've only added a TST #6 250 hp/630 tq plate and the Psychotty. I don't know if this plate has a "flywheel" rating or a "ground" rating. If I figure a 25% driveline loss, I'm making about 315 hp at the flywheel.
I calculated my torque using the following formula: (5250 x HP)/RPM. The printout gave the max HP at 48 mph in direct drive. On the way home, I noted the RPM at this speed in direct drive, which was 2125 rpm. So, my calculated torque is around 583 ft-lbs.
So, MORE POWER! But, I need to save my pennies for an upgraded transmission first. That is going to be expensive. Anybody care to email me what it cost them to get the full meal deal on a DTT installed?