damaged? if not i can't see almost 1/3 of the new price being a bad deal no matter what model it is. but when you ask for sound and hp gain thats when we kinda need to know what model it is, but why are you asking how it sounds when you clearly already heard it and like it? if i say it sounds like sh** are you not going to buy it? as for hp gains an exhaust doesn't really add ALOT! of hp to really worry about it especially on a r18. but hey thats just my opinion.