If I add a plenum spacer then later add an upgraded plenum are the effects of the spacer cancelled out or does the plenum spacer compliment the new plenum??

You want to go w/ one or the other. There comes a point where too much volume has a negative effect when trying to achieve optimal air flow.

get a spacer and call it a day. spend the rest of your money on something else.

If you have a REVUP engine, you definetly want to do both the spacer and MREV2 together.

If you have a non-REVUP engine, I suggest just the 5/16" spacer.

hey, after the 5/16 spacer wat else can i do beside intake and exhaust?
thanks in advance

Test pipes. They will add another nice little chunk of HP.
Then after that, engine management or a reflash.

well i plan to go FI in the future..is it safe to assume that on a non revup motor a spacer would have the same effects as a entire plenum?

thanks for the reply.
i wanna if instead of test pipes u just said, can i just replace the whole exhaust system?
is there gonna at a lot more horsepower? or just the same amount of power with keeping a stock exhaust and race test pipe.
thanks in advance

Hydrazine,

If you use the 1\2 inch spacer will there be any problems with aftermarket strut bars? I am about to place an order but dont want to cause future problems.

thanks

hey all, i have a 2006 g-coupe rev up motor, 6mt. i have installed a stillen tru-dual ext cat back, very intrested in fi. i want to stay singlr turbo for the ease of install and less stress on the motor. which should i go with??

Yes.

A whole exhaust system Vs test pipes both will make about the same gains.
6-8 HP.

But I do recommend doing both test pipes and and exhaust. They work very well together. 11-16 HP!

I don't think you can use a strut bar with the 1/2" spacer on the G35.

Are you asking about the spacer or turbo?

Yes, you can use the 5/16" spacer and MREV2 with a turbo kit no problem.

If you are talking about the turbo kit, the answer completely depends on the tune and build of your engine. Any of them can stress (or not stress) the engine. There is no definite answer available here.

5/16" is a nice mod IMO. Works very well across the band. That and a better intake is a good start.
If you plan to stay NA then pick a good cat-back exhaust solution that is hassle free and legal. (Stillen, Fast Intentions, etc.) THEN get the ECU reflashed, etc. for even more gain, drivability, (better a/f ratio with your new exhaust.)
I would also perk up the suspension, starting with sway bars which will do more to improve handling for the same level of go performance. Should keep it sweet. A strut bar is a good choice for the money.
Do basic changes like this first. It's cheaper and gives you a better all around performer. Tighter and more responsive. From that point you can decide if you want to go FI sometime in the future.
Only caution, if you do think you will go FI in the future pick the exhaust that will work best with it with little compromise in your everyday driving with no turbo or sc. You don't want to replace a whole exhaust system if you don't have to. But will probably want lower restriction cats if you do strap on a blower, etc.