RE: New Patriot XL
I don't have any experience with the Magnum 91 2c engine to know what it likes best for a speed airframe. I would consider starting with 11x8 or 12x6 or 7 for testing until you get used to it and then rip it with 11x9 for all out speed. The slight nose down stance is no big deal if you take off from paved runway, probably won't even need flaps if runway is long enough.