Get a lighter car with less expensive tires! (Very big grin!)
--Pat Kelly
Donald R McKenna wrote:
> Too all:
>
> I've commented on the great "first-effort" job Kieth and Nanda did Saturday,
> 5-20. However there is some food for thought, to be absorbed from our
> experience, about course layout/length and it's impact on tire wear at
> 3-Com.
>
> The length of the course (in time), yesterday, and the many, low speed,
> tight corners really increased tire wear per run. Although 3-Com is,
> technically, asphalt, it is quite abrasive due to the type of slurry coat.
> My tire wear measurement numbers, over the years, indicate that the 3-Com
> lot is the most abrasive lot we use following McClellan cement and the
> Castle cement site. By comparison Stockton wear is about 2/3 that of 3-Com
> and Mather wear is less than half. The old Oakland surface , before the new
> slurry (for which I don't yet have creditable numbers), was our lowest-wear
> site, slightly better than Mather.
>
> Before yesterday's event, we'd run 2900 seconds (60 runs @ 48 sec) on our
> tires on various surfaces (2 at Mather, 2 at Stockton, 1 at new-Oakland, 1
> at Laguna and 2 at 3-Com)
>
> The bottom line of this comment is that we ran tires with only 58% of the
> tread worn before the event and corded 3 of 4 on Saturday. If you ignore the
> tread rubber under the grooves, before you hit cord, the last 42% of tread
> was worn off in 13 runs totaling 1080 seconds.
>
> Do the arithmetic, 18% of our runs used 42+% of the tires. At that rate we'd
> get an average of 9, 4 run, entries per set of $900 tires.
>
> The message here is: In the future, don't plan to run long and tight corner
> courses on agressive surfaces like 3-Com, it's too expensive!!!
>
> Don
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