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Updated 10/21/02

2002 SFR Index
Street Touring indexes

The SFR Handicap Index ("PAX")


The PAX Index was a system of handicapping cars, so that drivers in different SCCA classes could compare times against each other.  John Kelly tells us it was invented by Jim McKamey for a series of autocrosses he ran at one time, and has been updated each year by Dave Beck. 

The RTP index is a separate set of indexes, calculated from different events, but basically similar.  They used to be separate, in any case, but for 2002 Dave Beck no longer maintains the PAX index, and Rick Ruth has combined them into the RTP/PAX index.  Info about it is maintained at

 http://www.scca-chicago.com/solo/indexes/rtp02.html

"This Index was developed by Rick Ruth and reflects results from over 30 large events including, the Tire RackŪ Solo II National Championships, National Tour, Subaru CenDiv, Chicago Region SCCA, Tri-State Sports Car Council and Wisconsin Autocrossers Inc events. This index is designed to incorporate some of the previous PAX substance with the RTP Index of the past"

This index is the basis for the SFR Handicap Index.

The RTP/PAX index for the fastest class (AM) is always 1.0. For any other class, multiply your time by the index for your class to get the time you theoretically would have run in an AM car. 

2002 SFR Handicap Index

San Francisco Region uses the straight RTP/PAX index, with the addition of entries for OSP and BSPV (which are not national classes and therefore do not have RTP/PAX indexes). We index OSP at .856 for people running in Novice and Street Tire classes, for example. 
 
Modified Prepared Street Prepared Stock
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  OSP .856 SS.836
AM1.000 AP.874 ASP.846 AS.828 
BM.951BP.867BSP.840BS.827 
CM.919 CP.854CSP.842CS.812 
DM.894DP.849DSP.820 DS.798 
EM.904 EP.868 ESP.826ES.802 
FM.897FP.865FSP.817FS.809 
F125.932SM.834BSPV.839GS.785 
FJr.815SM2

.856

  HS.779 
SFJr.774STS.786  STX.801
STS Street Tire.810STX Street Tire.830

Street Touring indexes

For 2002 all Street Touring classes must run "real street tires" while Stock and Street Prepared classes may run competition tires (e.g. Hoosier Autocrosser) which are a lot stickier and provide a significant performance improvement, perhaps 1-2 seconds per minute.  The RTP/PAX index takes this difference into account for indexed overall order of finish.  However, in classes that require the Stock and Street Prepared classes must run street tires (e.g. Novice, Street Tire) these indexes give Street Touring cars a significant advantage.  

As of 4/13/02, STS and STX cars running in Street Tire will be handicapped using these indexes:

   STS Street Tire .810
   STX Street Tire .830

Why the heck run STS-Street Tire?  Can't face real competition?

So far, We are still using the "standard" index for STS and STX in Novice classes.  If we ever have to combine these classes and any R tire class, we'll use the Street Tire indexes.  Currently only STX and STS are their Novice classes. 


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