RB25 Intake Manifold

[Rand0b]

Hi all

I have been searching around for an aftermarket Intake Manifold (FFP)

Wanted to see if there are any others out there as i have been searching for a few months and find a new one every week or so.

Overall Height will be the main concern (cant be much higher then Valve Covers). will be in 300zx Z32

Would like to stick with Long / Medium runner If possible. I may be able to do a cut and shut on the OEM one.

 

Plazman Top half

May be an option but could sit to high

 

Hypertune

short runner

 

CPC

Short runner

 

Greddy / Freddy

tried and true short runner

 

Speedtek Racing

Cast Aluminum 2 piece short runners

 

Rajab Racing

Top half, sits high currently only RB30 but in testing prototype for RB25 as of May 25

 

IMR Fabrication

plenum/runners welded to Oem flange look nice may be an option

 

China/ZERO Fab / ISR / NP Bosted

short runners

 

let me know if there are others out there that may fit the bill!

 

[Duncan]

Assuming you have horizontal space in the engine bay, any of those replacements that don't use the lower factory runners would be OK, wouldn't they? I run ebay china spec in my rb25/30 stagea. Also I am not sure how you (or the market) define long and short runners, in those pics there is a big variation. The length in mine looks visually similar to your last pic.

Of course, there is no science in my response; the bottom end torque is very drivable in my setup but it is a manual rb30 not a 25, and I don't have back to back dyno runs with factory runners so it may be worse down low than stock.

BTW if you are pushing the engine you will want individual cylinder o2 or temps when you tune. You can see visually that there is no way that all of those different designs will end up with the same air flowing into cylinder 1 as cylinder 6. 

Also, keep an eye on clearance to the clutch master (particularly if it is boosted) if you go with a cast FFP.

[Rand0b]

On 6/8/2022 at 5:15 PM, Duncan said:

Assuming you have horizontal space in the engine bay, any of those replacements that don't use the lower factory runners would be OK, wouldn't they? I run ebay china spec in my rb25/30 stagea. Also I am not sure how you (or the market) define long and short runners, in those pics there is a big variation. The length in mine looks visually similar to your last pic.

Of course, there is no science in my response; the bottom end torque is very drivable in my setup but it is a manual rb30 not a 25, and I don't have back to back dyno runs with factory runners so it may be worse down low than stock.

BTW if you are pushing the engine you will want individual cylinder o2 or temps when you tune. You can see visually that there is no way that all of those different designs will end up with the same air flowing into cylinder 1 as cylinder 6. 

Also, keep an eye on clearance to the clutch master (particularly if it is boosted) if you go with a cast FFP.

Agreed,
I guess I would consider long runner oem or rajab since they have their own runners and they bolt to the oem lower 

plasman (top half cap?) Mid length (just a collector that uses oem lower)

and all the rest short runners 

[robbo_rb180]

Plazmaman plenum on factory runners
Best combo there is for low/mid torque

Don't bother with anything else unless a 800hp drag car

[Duncan]

I'm pretty sure the Plazman on factory won't fit in the Z32, I assume the purpose of looking for a FFP is because the factory runners are too tall

[robbo_rb180]

The Greddy will definitely clear, I would only go genuine as the copies require a lot of work to clean up castings. I did have a genuine and it is very noticeable the differences

[Rand0b]

I know that greddy will work just wasnt sure if there was any other FFP that may be an in between. of the chin FFP vs the OEM / Plazman top half that may have longer runners

 

 

[GTSBoy]

I'd be close to 200% sure that there is no long/medium runner length option that you would want to use. That IMR manifold looks interesting (although, why the living f**k did they think they needed to lobsterback it together!!!???!! Just stupid!). But I'm pretty sure that there would be compromises wrt ancillaries and so on that you'd not like to live with. Getting to the stuff that lives under the manifold will be harder, and it's already hard enough. Plus, the alternator access looks less nice.

So, that leaves the shorter stuff, and if I had to go down that path, I'd just suck it up and pay for Hypertune.