I guess I am the only one using an escomposites.com carbon fiber pipe on my 46fx, the mac header, coupler, 2 spring clamps and cf tuned pipe with 3 baffles weighs 25% less than stock os muffler, I get 25% more power and a very linear throttle transition and instant power for 3d, It does cost $100 but I have been using it for over 5 years on four diff airplanes and 3 diff engines. it also redistributes the weight back off the nose. it is so quiet that many people think it is an electric - last year at an airshow I hovered my diablotin side by side with an electric diablotin - mine was much quieter - you cannot hear anything. which is great when you are hovering next to your ear.