New PPF Formula?

[arena]

Vytenis wrote:

If handicapping cars was easy, they'd have girl/boy scouts doing it.

Previous years' RTR participants'data show less than 12% difference in PPF across the spectrum of cars, tires, modifications, etc.

SCCA PAX has approx. 7% difference from SS through HS (stock) classes, which covers everything from Corvettes to Ford Fiestas. SCCA does not take tire grip into account in most classes.

I agree that HP, weight, grip, and possibly car age will factor into predicted performance. How this is quantified, I'm not sure. The SCCA PAX and definitely old Maverick region PPF are derived from a large data set.

"V"

Essentially, I have averaged all of our participants tire widths, compounds, vehichle weight and horespowers. Then for each person I calculate what % above or below the average thier car is in each of those categories.

So my car:

F tire= 6.3% larger than average

R tire= 6.3% larger than average

Compound = 19% sticker than average

Weight = 2.5% heavier than average

Power = 11% more powerful than average

So I take all that, correct for the different standard deviations, correct so that the three measurements of width and tire compound count for 1/3 of the final number and average out the rest and get my PPF = 1.033 or 3.3% faster than the average car.

Simple, right?