I sent my trx5b pipe and turbine core 2 Q to Jerry Hall last year. He did some dyno testing with it. From what I remember of the Q silencer is that it lost like 2 or 3 horsepower compared to the super loud ESR silencer. I swap back and forth between the Q and a standard FMF with a spark arrestor bolted on to the back. If I don't get sound checked, I run the standard. I can feel a difference on my 330 but not so much on my 310. But the porting is way different between the 2 machines...