The battle floyd isn't bad, but you'd do better to modifiy it a bunch. If you look at my Rapier instructions at www.MidAtlanticCombat.com and steal what you want from there, you'll get a much better end result.

I assume you're asking about the .15 on a foam core fuse for an SSC-type plane? for SSC class with the minimum weight of 2.5lbs, you want about 64" wingspan and a bit more than 600sqin. If you want to keep the weight down, and won't be using SSC rules with the 8x3 prop and limited RPM, then the same fuse will go a lot faster with a 48" wing and a weight just under 2lbs. That's basically what I used to do when we flew Open A class around here for several years, back before SSC existed.