I was thinking of adding a catless downpipe before my tune. How much hp have you guys seen by just swapping out down pipes?
S SRH_STi · Registered Joined Jul 28, 2008 · 2,187 Posts #5 · Jun 17, 2009 View full thread Darkhrse99 said: I was thinking of adding a catless downpipe before my tune. How much hp have you guys seen by just swapping out down pipes? Click to expand... Do you mean without a tune? Or with a tune but without a catback?
Darkhrse99 said: I was thinking of adding a catless downpipe before my tune. How much hp have you guys seen by just swapping out down pipes? Click to expand... Do you mean without a tune? Or with a tune but without a catback?
