Can I get away with using a 2.5 inch bore when trying to achieve 370ish bhp?? Setup will be 255 fuel pump, hks headers, 2.5 full decat, apexi power fc, andy forest tdo5 20g, 88 front mount, 550 denso injectors. Thanks in advance and happy new year.

 

Im sure ive read that AndyF is making some 450bhp on a 2.5" exhaust system. This is I believe is on a Spec C car he has. Someone is bound to correct me if I made an error.

Andy

Ps Im running about 380bhp on a 2.5" system.

 

Great, thanks for reply. I will at least give it a go then!

 

I would say it's down to how good a 2.5" system it is. A free flowing 2.5 will always be better than a poor 3" system IMHO..