i just purchased my '04 g35 cpe mt6 2 days ago and i had a few questions. ive been reading all over this site about rev-up or non rev-up engines. is my car rev or non? whats the difference, about 15 stock hp or something? also, i was looking to get the Kinetix plenum, and i read somewhere how you shouldnt necessarily use a spacer on a non-rev vq?? wanted to get some input on what i should do in this dept if my car is in fact a non-rev. do people use a spacer in addition an aftermarket plenum like the kinetix? i know theres threads all over the place addressing these separate issues, just wanted to tie them all in for my specific need. thanks.

 

You don't have a rev-up motor. Rev-up are for 05-07. The rev-up motor has a higher rpm range than the non-rev-up. As for spacers...i don't have much knowledge about because i don't have one. never really cared for it. But someone will chime in and help you on that one.

And welcome to the Board Nye.

 

^ he is right

get a motordyne spacer. i dont think there are any additional gains to be had from pairing it with a bigger upper manifold. also for future reference, dont buy kinetx products. generally speaking they are poorly made.

 

thats weird, i saw quite a few ppl on here raving over that kinetix plenum. so theres no problem putting a spacer on a non-rev vq then?

 

there is no problem with a spacer on any G35 or 350Z motor other than HR and upcoming 3.7 (yet)... As for Kinetix, I'm not sure why someone said they are poorly made - they have are quality products. Early versions of their plenums had issues but they have been fine for quite a while now.

You do not need (and can’t fit anyway) a spacer and an aftermarket plenum of any kind... you only need one or the other.

I have 1/2" Motordyne spacer on an 04 (which is non-revup) - and it's one of the best bang for the buck mods I've done.

 

ah ok. so u would recommend a spacer over a kinetix plenum then??

 

Personally yes. For 4 simple reasons:
1) Motordyne products are proven by boatloads of users with not 1 negative issue (that I am aware of)
2) it is a very stealth and economical means of achieving the exact same performance as aftermarket plenum
3) Tony is VERY knowledgeable and provides about the best customer service I've experienced in any industry.
4) from personal experience it has been a very real performance producing mod

I have Stillen CAI w/Ztube, Stillen catback exhaust, Crawford Cats, TS ECU, Stillen anti-sway bars, Eibach Pro lowering springs, some other minor tweaks. And without a doubt the 1/2" spacer gave possible the most noticeable improvement. The HFC might be comparable (if not, definitely 2nd).

 

ok thanks a lot. so i should go 1/2" as opposed to 5/16" then? whats the advantages/disadvantages between the 2?

 

There's alot more to that.

First, only 05-07 6MT's are rev-ups; autos not included.

Rev-Up also has a more adaptable ECU; some minor tweaks and improved engine internals.

As for the spacer; 5/16 is more popular because it has more mid-range power and torque over the 1/2. The 1/2 is proven to have more top end, but nothing significant (maybe 2-3 more hp). I personally have a 5/16, which I have not installed yet.

I always recommend the 5/16 over any other size

Mrev2 is more specifically for the rev-ups.

.

 

there are a bunch of threads about it... but in a nutshell 5/16" will give you slightly better mid range gains - 1/2" slight better top end. SportZ mag did a shoot-out its good info if you can get your hands on a copy.

Honestly, either will be a good choice. It is very doubtful that anyone’s dyno-butt could tell the difference between the 2... actual dyno numbers might show slightly variable as mentioned above.

Also some people like to use 5/16" if they keep the OEM engine cover on... however you can use the cover with 1/2" as well. On the G it's not as critical as the Z (the Z needs 5/16" to clear strut bar).

I have the Iso Thermal kit which is a valve to shut off (hot) coolant flow to throttle body and a thermal isolating gasket between the lower collector and intake manifold - both to help keep plenum temps down in an effort to maintain colder intake air to the combustion chamber.

How much will you gain in performance with the Iso Thermal? Not sure... but it definitely keeps the plenum cooler! You can easily place the palm of your hand indefinitely on my plenum even after motor has reach normal operating temps... I've palmed it after having driven 50 miles and its does not burn to the touch... Do not try this with your OEM plenum configuration, you will say ouch.

 

all good info. thanks.