re: <AUTO-X> street tires vs. R1's - lap time difference?

[Ron Katona <ron3b@xxxxxxxx>]

Brad Snakenberg wrote:
> I've never autocrossed on R-compound tires, and as I'm becoming more
> experienced I'm curious to know what difference in lap times I could expect
> if I got some R1's.
> 
> I'm driving a stock 95 M3 on Pilot's. Last Sunday my best time at Ft. Meade
> was 64.4 seconds.

That's a good time already! R1s are going out of production soon, so
you'd better hurry if you want a set (may already be hard to find in the
popular M3 sizes). No one really knows how good BFG's replacement tire
(G-Force) will be for autocross, although I've read some good reviews
from road racers.

A good rule of thumb for R1s vs. street tires is 1 second for every 30
seconds of course. So, about 2+ seconds for that run. Course layout and
your familiarity with the sticky tires will vary that figure.

Just for the heck of it, I swapped my R1s for street tires during fun
runs at the event we ran at Jack Kent Cooke stadium. 87.0 on 205/60-15
R1s, 90.5 on 225/50-16 Dunlop D40M2s.
- -- 
Ron Katona mailto:ron3b@domain.elided
'97 318ti Active/Sport
Laurel, MD  BMWCCA #139211 (NCC)

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