exhaust restriction question. ...
 

Ritw so im coming to then end of my build now and im about to order my twinscroll downpipe from RCM.

I have a Blitz Nur Spec r 3 inch cat back. But from what ive seen the exhaust flanges are 2.5inch then go uo to 3 inch... so I hqve 2 options.

1 order 3 inch decat downpipe with 2.5 flange.

or

2 order downpipe with 3inch flange and cut and weld cat back flanges to 3inch ones...


so is there much restriction on the flanges and is it worth doing?

Thanks ryan

I was running a 321t with a 3" exhaust but had a 2.5" flange between the down pipe and centre and when changed to 3" all the way it jumped from 440-480 bhp so made quite a difference.(this was both with 15% meth)

Bloody hell... well worth it then

Hi Ryan

Yes exhaust can cause restriction and I would swap exhaust for 3",if you are thinking to run more than 400bhp



Thanks,Jura

[QUOTE=jura11;11367541]Hi Ryan

Yes exhaust can cause restriction and I would swap exhaust for 3",if you are thinking to run more than 400bhp


Cheers jura

exhaust itself is 3inch.. just the flanges on the nur spec r are 2.5 in