rsx? how much hp gain? i have a 02 base rsx auto. I wanna buy this exhaust from someone. Invidia Acura RSX non-s JDM Polished Cat Back Exhaust Gt300 2002. but i wanna know how much HORSEPOWER gain will i get? heres the link on craiglist of the exhaust --> http://inlandempire.craigslist.org/pts/2631248396.html