I have already installed a twin flow intake GMAFS and a Halltech ported throttle body to my Z. I want some opinions on what I should do next that would give me the best power increase for the least price. I am considering long tbe headers and an off road x-pipe. How much hp would this add?
Remove mass air screen 1-2 rwhp
Airbox (you did)- I never saw any gain from donaldson on the dyno and car only made 7rwhp more with everything removed in front of mass air. Others will strongly sell otherwise.
Best in my mind (which I might do soon)
Off road x-pipe which eliminates pup cats and cat itself and a pair of sims.
For $400 removing all of those cat's must make at least 10rwhp in my mind.
19 rwhp and rwt with DRM long tubes when car was mostly stock. My car started out at 327 rwhp. With Donaldson and Corsas we were at 342 rwhp and then headers we were at 361 rwhp! All on same dynojet and not many miles of driving in between.