I used to fly an SS 40 with an OS 45 FSR turning a 10X7 and there was never a hint of flutter. Even in full throttle straight down dives. A piped 46 turning an 11X5 will not even come close to over speeding the airframe. This plane, while it moves along pretty nicely, is not a rocket ship. It's just too draggy. Use the pipe to turn a larger prop and have fun with the vertical performance.

John