I have a 2006 G35 Coupe. Already have cold air, Motordyne upper plenum and Fast Intentions exhaust. My plan is to put in a75mm throttle body , polish the plenum and intake. My question is it worth adding a upgraded lower plenum and a spacer. What spacer works best 5/16 or 1/2 inch? Is copper worth it? Then a tune.

 

Welcome to the forum. Looks like you’ve researched some important upgrades and bought some good stuff already. When you say motordyne upper plenum, I assume you mean the MREV2 because you have a Revup?

 

yes I meant lower plenum. What I'm thinking about doing is pulling it apart and porting and polishing the manifold, lower plenum. Wondering if it is worth it adding a aftermarket upper like Kinetex and a 75mm throttle body or just stay with polishing my stock upper and 5/16 spacer? Also if I go with Linetex upper do I still use the 5/16 spacer?

 

If you have the MREV2, you do not need the spacer. The MREV2's modifications solve the intake air distribution choke point issues.

 

New spark plugs and a tune (by me) and it'll feel like a brand new car