Looking for intake plenums

[Fiendish]

I will have my RB25 clip in the next week and my first bolt-on will be an intake manifold. I would like to find a cheaper, alternative to the Greddy/Trust manifold, but it seems there aren't too many out there. If worse comes to worse i will bite the bullet and get the Greddy.

So far all i know of are the Sub Zero and the UH Unstable Hybrids plenums. I haven't seen a pic of either really. I caught a couple of small pics of the Sub Zero plenum on this forum, but couldn't really see much. Does anyone have an more information about these products and where i can find a manifold for my RB?

Does anyone have any of these manifolds, including the Greddy? And what are your reviews of them? HP gains? Fitment issues?

Thanks in advance.

[Imissmyturbo]

I can warn you that those plenums that are foward facing can cause air distribution problems. I don't think it's a great concern unless you are going to be pusing alot of HP and tunning it to it's limits for fuel. But I would say on an otherwise stock engine it will work ok.

[93RPS13]

i dont get that... look at the GTR

[Bluefire]

GTR is individual throttle body though... The air distribution problem is negligible though with good tuning. The stock manifold already has a bad air distribution ie.. leaning in cylinders 1 and 6. And you should definitely be able to see it when you make more power. So the next step would be a greddy manifold which doesn't have the perfect design but is still better than the stocker for higher hp applications

-Bluefire

[Imissmyturbo]

From what I read on the Skylines down under board is the stock RB25 manifold has good distribution and will flow well till about 350-400 WHP. (About the same as what the stock internals should be taken to)

[Bluefire]

Well yeah thats what I meant... you won't notice the leaning conditions until you hit about 350-400. Then your best option is the greddy manifold for more flow. I dunno, maybe its just me but I feel like if you don't eventually hit the 350-400 hp mark on the RB25, it would be waste of potential... haha i dunno... maybe I better get my lazy but out of this dang computer chair and finish my swap!!

-Bluefire

[jbanach77]

I dunno, maybe its just me but I feel like if you don't eventually hit the 350-400 hp mark on the RB25, it would be waste of potential...

DITTO!!!

[GTR Shop]

Depends on what you're after. An outfit did a test with a Std and GTR manifold on a RB20.The std manifold made less bottom and more top end, while the GTR made more bottom and less top end.. opposite to what you think, but the dyno plots prove the point!