Okay, I'm going with the Flowtech Raptor mounted in the stock position with 2' pipe from the cat to it, 2.25" out the back. I had a motorcycle (streetbike) silencer 18" from the cat on 2.25" pipe and confirmed that I did suffer some HP loss. Very bad with so little to begin with. It didn't sound bad, just too little back pressure. I'll post the results of my performance test once I have it all set.