Dick: You are right about the reed spitting back into fuse, but maybe a veocity stack or a simple air plenum could take care of that. I like the idea of the rotor valve, but it seems like the close fit they have would wear out and the performance may be lost. How long do these rear rotors last?? As far as tunned pipes go how many rc ,ers use them on gas. It is more$$ and weight. Biggest problem is how to fit one on/or in plane. Cap,n John