----- Original Message -----
From: "Wentzel" <greendot1@comcast.net>
> I think there was discussion when I had no interest, but now I do (have an
> interest)
>
> Is there a PAX type number to compare performance on street tires to
> performance on "R" tires?
I haven't seen anything published, but the old rule of thumb used to give
R-compounds a 2-second advantage on a minute course, yielding a modifier of
0.968.
Some of last year's tire tests in Grassroots Motorsports indicate that the
R-compound advantage has improved, although not evenly. IIRC, one of last
year's tests showed Kumhos (both Ecstas and Victoracers) about a second
behind Hoosiers, and about a second or so ahead of Falken Azenis...on a
*40*-second course. Empirically, score a "normal" street tire (if there is
such a thing) another half-second behind the Azenis.
Using the Hoosiers as a baseline (1.000), that would make the modifiers:
Kumho 0.976
Azenis 0.952
"Normal" 0.941
That last would equate to a 3.5-second penalty on a minute-long course.
Of course, all this really proves is that I'm dangerous with a magazine
article and a calculator -- but it's as good a place as any to start. :)
Jamie
'92 Prelude Si
Speed Demon Racing
http://www.mindspring.com/~jsculerati/sdr
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