HI JM! I do have a .15 sized pipe, but I don't know if I am up to the challenge of making my own header. I've got some aluminum brazing rod and flux. I might end up going with a fixed venturi and open exhaust, that would be the lightest option, then I could dump some of the battery ballast in back. These planes are kind of fast to a point, but then you run into the wall. The power/drag/weight/speed problem. This engine so far has only been on bulky planes, so it will be interesting to see it unwind.

PATRICK, It's kind of a compliment to hear that a high performance plane handles like a trainer. It would be a good size for that MVVS .21! Then what kind of trainer would it be for those guys? I'll tell you, it would be a POTTY TRAINER!!