2008 Challenger SRT8 Kooks longtube headers Magnaflow Catback K&N CAI Stage 1 Camshaft PPP Stage 2 CNC Heads Diablosport Predator 89rwhp/79rwtq peak increase 69rwhp/81rwtq average increase from 3,000rpm to 6,000rpm 108hp/96tq gain over stock at the crank This engine is now making 543hp/532tq.
I usually go with 17.5% since that was what our drivetrain loss was when we had an engine on an engine dyno and then stuck it in a car. that engine was 463rwhp in the car and 560hp on the engine dyno.
Ahh, I C that now. Andy's second post was referring to some other motor...just to clarify where he was getting the higher HP number from.
