Originally Posted by gq_626

I have one on my car, and I did back to back dyno testing with my Greddy TT at 8.5psi. The gains were surprisingly large. Roughly 30-40whp across the board. Now, I also changed to a fresh set of plugs, so some of the gains could be attributed to that. But based on my experience, I am a believe in the Crawford plenum for forced induction.

The Plenum did cause me to lean out slighltly, which necessitating a slight retune of my fuel maps...thats the only thing to keep in mind.