tire moving on rim at the track

[ianacole]

I have a theory on this, for all it's worth.

Disclaimer: All my racing experience is in my old '02 VW GTI 1.8T. I've only done HPDE and open lapping in the Boxster as I collect parts for my Spec build.

Theory: All rotation happens under braking, but the fronts are rotating further around the rim than the rears. I further theorize that the driver's side is rotating counter-clockwise, with the passenger side going clockwise.

Reasoning: I don't feel like these cars generate as much rotational force under acceleration as braking. The only time I could see a great deal of acceleration force occurring is in standing starts, which I don't think occurs very often. Think about when you hear tires: under braking, or in corners, never under acceleration out of a corner. I haven't had any telemetry hooked up in the Boxster, but in the VW, with ~215HP at the wheels, I could not break 1G under acceleration, but could regularly in braking and cornering.

Anyone have any in-car telemetry they could share showing peak forces during acceleration and braking?