Gtr - Hi Flow Manifolds And Standard Turbos

[Antimatter]

Hi Guys

I have purchased a pair of hi flow stainless manifolds for my R32 gtr to use with my steel wheeled turbos. The dilema I am facing however is that even though these manifold fit up to the turbos - the opening on the flange of manifolds is about 30% larger than the opening on the exhaust housing on my steel wheeled std turbos. My concern is that while the manifolds themselves may have superior flow the benefit will be lost by the "disturbance" in gas flow cased by the "step" in between the mating flanges.

My initial thought was to revert to standard manifolds - as they should still flow well enough fo all that I would be able to achive with my turbos. HOWEVER - I would love to use these manifolds - and had entertained thoughts of "porting" the flange on my turbo exhaust housing, though it has been since suggested that this would mess with A/R ratio and is not advisable (?).

Ultimately - I want to do whatever I can to help with turbo spool up / minimise lag. (henceforth staying with standard turbo housings).

Opinions on this matter would be most welcome.

Thanks

Steve

[savage GTR]

how about fiting a plate in between the two surfaces which could then be shaped or ground out from one size to the other. it would have to be probably be atleast on inch thick though and this would effect the height of the turbos or possibly be a space issue. if you have the space though it might work

[R31Nismoid]

The manifolds give no gain, better of keeping the stockers.

I've had that drilled into my brain for months now hehehe

If you were running a big housing turbo, different... but look @ the size of the stock housing... you dont get to fit much in there increasing the flow to the housing wont work so well as its only gonna fit through there at a certain rate

[BOOSTD]

I'm runnig these cheap manifolds, ported my 2530's to suit. makes 360rwkw on 12psi on the std PFC map.

[CruiseLiner]

I'm runnig these cheap manifolds, ported my 2530's to suit. makes 360rwkw on 12psi on the std PFC map.

farrrkk not bad, got a dyno graph with it showing boost?