Ive just converted my mk2 orion to EFi turbo and ive currently got possesion of 2 2.5inch exhaust system for a S2 RST, one magnex and one scorpion. The scorpion bkbox looks very restrictive internally, but sounds abit nicer than the magnex at idle.

Before i extend the tailpipe to suit the orion, i wana know what performance/sound difference there is in a 3" system?

 

3" is for real big power specs from what I have read on here

 

2.5 inch with 3' tail is fine unless you are going for massive power and stay clear of the scorpion as they are restrictive the internal diameter coming out of the silencer into the tailpipe is no bigger than the standard exhaust

 

It does look restrictive, but the box is alot smaller than the magnex (maybe that has somthing todo with the smaller internal bore size) and sounds so much better.

What is the power limit of a 2.5" system?

 

300+ isnt it?

 

Thats what I was always told. 3" after 300bhp.

 

nms do the the best 3" system but as said its only required on big power cars

 

I think i'l be ok with the 2.5" system then, as im only planning on 180bhp and around 14-15psi