What % or est hp to they really add? Is it worth it?

2003 BLK/BLK 6-spd Injen clear corners

 

Crawford tells us the their pleneum add +9hp at the usual hp peak and that it goes on to prevent as much power fall off past that peak, to redline. As an owner of the crawford, I fully concur that's exactly what it does, that is my experience. From the very first trip through the gears after the install, kissing the rev limiter in every gear, I knew every penny I'd just spend was worth it. No other mod, except my custom exhaust has brought the dollar to results factor front and center as well as the Crawford pleneum. I highly recommend it.

"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt