The Brute exhaust was designed to be the ultimate, best performing free-flowing exhaust made for the R3, regardless of whatever work you have or haven't done to your engine, but yes, since management here has obstinately not seen fit to allow perhaps the most knowledgeable person (Art/IMFASTTOO) about the Rocket III on either of the owner's sites to participate here, go on over to .com and ask the Guru himself!