exhaust manifold pipe diameter whats best size?

[whipsey]

i'm looking at getting some stainless tubing to sort out my six branch manifold for my m30 project but im a bit unsure as to what size to use i was thinking of 2 inch tubing but unsure if its worth going bigger any ideas?

[wullie325i]

2.5" maybe a quarter more.

[whipsey]

thats what i was looking at really just not sure what size is gonna have adverse effects on pressure etc

[wullie325i]

2.5" should be good for standard or even a bit of modding.

you only really need to start going 3"+ when you are going for crazy power.

[gooner1]

Shaun, what diameter is the M3 one
When i was attempting my conversion, the above seemed to be the exhaust to go with.
That may well have changed by now though.

[whipsey]

it's only reallygoingto be standard power at the minute but might put a turbo on at later date

[whipsey]

Shaun, what diameter is the M3 one
When i was attempting my conversion, the above seemed to be the exhaust to go with.
That may well have changed by now though.

ive got no idea rob only really just looking at the pipes i've got he flanges already this is pretty much al i have to sort now so i can finally get it finished