FWIW, the 66' radius is what we used at our school/test & tune last year. That's a 66' "inside" radius. Add another 2 feet for the cones and chalk line, another foot or so for driver innacuracy, and that puts the centerline of the average car at pretty close to 75 feet, which is what we based our calculations on. It worked out to be pretty accurate for those who kept a tightish line. But there were only 2 or 3 of us that did, everyone else either went 3-4 feet or more from the cones or was just inconsistent. I pulled .86 G's on street tires, which seems about right for that surface. Jeremy (w0rd) pulled .85 on Azenis, and Billy Young pulled .81. Everyone else was under .80.

BUT... I wouldn't count on a great deal of time being available after this event unless the attendance turns out to be low. And it might, with the PCA guys doing Sebring and the Neon guys doing dyno testing, we've lose a few right there.

This skidpad is probably not going to be flat, either. As close as one side of it is to the drain grate, it won't be even enough to give consistent results. But it will be good enough to give a driver some feedback on their car's steady-state cornering tendencies and their ability to control it... which is what I was after.