I put the Kerker 4-2-1 pipes and Supertrapp muffler on the VMax a week ago, but today was my first chance to take it out for an extended ride. Oh baby. Imagine a small block Chevy with glass packs, only about an octave higher in register. Supertrapps get louder as you put more discs under the end cap. It had 13 in it when I got it, backed it off to 4 to save some hearing loss. Lighter, louder, faster!