Krade

I am thinking of getting a nearly new P1 back box exhaust for my 95 WRX.
The car has an HKS filter on it and I know this is a subjective question but how much better performance would the P1 exhaust add to the car. I know there are better back boxes out there but its more a question of Funds than anything else at the moment.

Ken E

Don't think you would get much of a performance increase but it would sound better, decatting the downpipe will give more performance improvement.

Devil's Refugee

Better off saving up for a full decat exhaust mate.
As said, you'll experience a nicer "burble" from the back end, but not much more of a noticeable performance gain really.

Krade

Cheers Guys
I thought it wouldnt do too much maybe 1 or 3 bhp but I can live without it Im not really after more power just a nice exhaust note The cars got 245ish bhp as it is