question on headers
 

what kind of gains am i looking at with mazdatrix headers and a straight pipe instead of the presilencer...?

You wont gain any power, and it will be a lot louder. The silencers RB makes are not restrictive at all.

hmmm...i see...so no difference between presilencer and straight pipe at all. what gains do i get for the setup tho with headers/straight pipe? my car's basically stock right now. thanx for the replies.

20-25hp...Your car won't be TOO loud as long as you keep the stock mufflers, but you'll be severely restricting flow with the stockers. I have a straightpipe on(headers not on yet) and my car is still pretty decently quite, just meaner sounding with no cats, and with stock catback.