Hi, I am new here, I just signed up today. I have a question about purchasing/installing an ebay Shift Works or Kinetix Upper Intake plenum manifold on my 2003 Infiniti G35 Coupe with 5-speed automatic transmission. I am wondering if this modification is basically worth the nearly 270 bucks they are both charging on ebay as far as gaining solid horsepower and torque or if it is better to just wait and save for the MREV2 lower intake manifold on my daily driver. I currently have NGK Iridium plugs, an ETD, an Injen CAI, and a 5/16 intake manifold spacer as far as bolt-ons and am looking for more to add power and performance to my daily driver. Thanks

No, it's not worth installing either one! You can quit saving your $$ for the MREV2 manifold, cost isn't worth the increase in WHP if there is any! So far the only mod you've made to increase HP is the plenum spacer! Since you're looking for HP increase your next mod s/b a quality cat-back exhaust followed by Fast Intention high flow cats (HFCs) or ART pipes! Then you can save your $$ for a Osiris tune...Gary

Thanks Gary, that was very helpful. Now I can start planning my next three mods.
- Brad

You've already got a plenum spacer, don't need the manifold. its an either or type of thing. Also the MREV doesn't do much for the non rev up DE's (your motor). I would do exhaust and a tune then call it good for go fast stuff.

Just ordered my Fast Intention resonated HFCs. Next I'll probably go with an HKS cat-back exhaust to compliment them. Also, what type of gains could I expect from a set of Stillen Grounding wires? I appreciate the great feedback, it has been a huge help. Thanks again,
- Brad

Brad, grounding wires allow your AT to shift smoother, that's about the only result you can really feel! Rather than getting them from Stillen and having to install wires you don't need give Sean (SXEXCX) a PM. He has the quality wires you need, the cost is reasonable!
Gary

Talked to a guy today who has a Kinetix intake on his '04 5AT, said he got 5 hp out of it. He seemed happy about it but IMO, that's not much gain for the cost unless you pick it up used.

This is what he had, the whole manifold.

If nothing else that's a beautiful piece of bolt-on equipment, I'm super skeptical of their company though because the advertisement claims "+30 something horsepower!!" in an ad I saw once. Super sleazy way of making the claim too it was something like +5 hp at the low end, +10hp in the mid range, and +15hp at the high end rpms... =30 hp right???

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It is a gorgeous manifold, that's for sure.

Sadly a 5-10 HP gain won't be detectable from a butt dyno. Assuming a stock non-revup motor puts down around 210 to the rear wheels we're talking about a 2-5% increase (general numbers) and anyone who says they can feel a difference is delusional, senile or just in denial that the $300 or more they spent was a waste of money and time.

No doubt it's looks good, lots of bling! However, you get the same RHP results from Motordyne's plenum spacer for a lot less $$! Kinetix works best when combined with FI! Manufactures have been exaggerating hp gains since Ford pushed his T out of the barn! Motordyne is the only one that can prove his gains using a dyno on everything he sells!
Gary