slight loss in tq but a good jump in HP (mostly top end mod) I hate the sound of a subaru w/ equal length headers, sounds like a honda. they're a good idea if you're doing a turbo swap but with the stock turbo setup its probably not worth the $
When I was talking with the guys from Gruppe S a while back, the guy I spoke with said that the STi guys are getting as much as 20whp from a header. Obviously its not just the how much hp but where the hp/tq is made that really counts, but it sounds like a reasonable mod, considering the Fxt has a more restrictive factory header to begin with.
Unequal length headers probably aren't as efficient, but helps keep the boxer sound intact I think.
yeah, on my wife's xt we have an equal length header. my wife and i both love the boxer rumble and hate what her xt sounds like now. very much like a honda... our next move will be to get a stealthback and sti axleback so we can muffle some of that fartcan noise... i do believe we did feel some top end power but be advised that it is via butt-dyno only.