ptxman,

The horizontal stabilizer on a pylon racer has a limited function most of the time, just as most horizontal stabilizers have limited function most of the time. Generally, the amount of downforce required of the stab is small, as long as the CG is in a fairly neutral position. You are right, since the plane never flies inverted, it could give a small reduction in drag to give the stab a bit of 'upside down' camber, especially if you could get it right on so that level flight would require no elevator deflection. This makes me wonder whether there is more potential gain in optimizing for level flight or for turns. I think the gain would be fairly small in either case, but that is a mostly uneducated guess. I don't think there is any special sensitivity to the LE radius. I think the main issues involving LE radius kick in in the neighborhood of stall, and there is no reason that the stab should be near stall. I think the best choices for LE radius and hinge line are the lowest drag choices.

FWIW,

banktoturn