The bassani x pipe has a smooth transition from the 2 pipes coming in to the 2 going out. The prochamber has a geometrically shaped box in the middle. I fail to see how a box would be superior to a smooth transition in regards to velocity and flow. It makes absolutely no sense to me. If I want the most power out of my combo, which I do, Id like to see some convincing in the form of a dyno sheet. I guess I need some subtantial proof before I go selling my stainless steel bassani x pipe, in exchange for a lower quality prochamber, then go buy 2 cats, then to the exhaust shop to have the cats added. If 8-10RWHP is infact true, going this far out of my way could be justified. But from the sounds of it, I cant see any gain.. maybe 2HP on a good day. Like i said, I just would like to see the results, so if anyone could post anything solid, please do.