Hey everyone, need some adive. Becasue of the high costs of shipping an ehxaust (I live in Grenada) I am thinkning of getting one made. I spoke to the local Mitsubishi dealer, and he had one made for his Evo 5 with much success (mandrel bends and all).
I just want to know if there is anything information i should provide the exhause guy with before I go into this so that he can build me a kickass piece. I am thinking 3" all the way should be good. Any thoughts.

 

3" straight through will give great gains over the OEM exhaust, but most go for 2.5".

3" will give greater top end (high revs) gains, whereas the 2.5" will give greater mid-range. Having driven cars with both, I would go 2.5" as mid range grunt is more usable than top end, and seem to suit the character of the car better.