Polishing and porting exhaust manifold - is it worth doing? Does it require remap?
 

I have read in some places that port and polish (P&P) job on WRX exhaust manifold can give significant profits. Has anyone here done it and really felt the difference? Especially in spool up and pedal response?

Also if I decide to do it, while I have the manifold out of the car, can I put it back without a remap? I am curently on PPP map in WRX 03 and have plans for a remap in a year or so. I know that there could be 0 gains without remap, but is it safe?

If it was my car I would port it and wouldn't give it a second thought. I have a full 3" bore sports exhaust with sports cat and japspeed manifold. With ppp and no remap. Never had a problem with my car.

Of course a remap is the best way. But wouldn't worrry about porting. It's just letting the exhaust flow more freely.

Must drive like Miss Daisey :lol1: