Get a header and a high flow cat to complete your I/H/C/E system. When I installed my JDM ITR header and a Carsound cat (already hade an AEM Cold air and an Apexi WS exhaust), I dropped a full half second off my quarter mile time. THEN you could get a V-AFC to get on the dyno and tune with to fine tune your a/f ratio and pull some power that way. DON'T get an IM until you at least have cams and pistons, it will kill your low end and midrange power for some real small HP in the upper rpm range, and you'll be slower overall.

Answer :snoopy's: q's and this one for us: Do you want midrange power or high end power?
Then we can help you more.