RE: GP ultimate bipe power setup
I don't know about the electrics, but I don't think the .53 would have any problems pulling the plane around, especially with a bit of lightening here and there. I built mine years ago as a younger lad who didn't think much about lightening the airframe while building, and my Webra .50 pulls it almost out of sight vertically straight off the runway. It won't pull out of a hover, but it'll hold one pretty well. If that Irvine has similar power I would think it'd be a good match for the plane, again especially if you lighten it during the build.