[barrylnv]

+1 to above Cacadeech. I originally had a Hennessey on mine and you could noticeably hear a vacuum sounds even at part throttle. Sounded great. No idle difference but definitely part throttle and WOT sound difference. I think the ones that have a very well sealed heat shield or sealed airbox might not produce that same sound but I don't know. You can buy an heat shield for the Hennessey, and I did, but it has a terrible seal. Sounded same with and without it. Mine now has a different intake and shield, way better design (tubes, dual cone filter, and sealed heat shield - comes with LPE's 650 package) and is sure looks great but I can't anything over the huge whine of that blower!