I am still on the fence, but would like to decide what engine to use.  I am building a Large wing Velocity, not the XL.  One of the original designers of that version of the plane recommends that an  io-540 250 horse would be the ideal engine.  Now I was thinking of either a 2 rotor that would be turboed to 200+ hp at sl not at 10K or a NA 3 rotor.

Bob;

I was on that same fence for my SE RG four+ years ago; and opted for the NA 20B.  But that was before the Renesis.  Now it seems clear to go with turbo Renesis.  It will give you maybe 230+ at sea level, no boost, and the beauty is you can have that power at high altitude with the turbo.  You can get a new Renesis for the price of a used/overhauled 20B.

Al