Hey Weru,

I just maidend my Extra this weekend. It's a sweet little plane.

I'd say for a .46 size engine and sport flying you'd be pretty good with a 12x4, 11x5, or maybe even a 11x6. The 12x4 would be a bit better for 3d, but on this model will also work well for sport flying as well. the 11x5-6 will give you a bit more straight line speed. My preference on porps has always been APC, FWIW.

For CG, the book says to start at 4 inches behind the leading edge. Since this is your second plane and you want to do sport flying, I'd recommend starting at 3 inches behind the leading edge and go from there.