Boyracer40

Who did the math for the SCCA PAX multipliers for auto-x?

I currently run my '08 CR and did an event yesterday. My co-driver looked up how PAX works for stock class, which up until yesterday, I thought was pretty straightforward. We run in a 'street tire' stock class, locally.

SS - .856
AS - .843
BS - .835
CS - .837
DS - .819
ES - .823
FS - .833
GS - .821
HS - .802

Just the fact that the numbers don't progressively decrease as you move down in class makes no sense.

To put it in perspective the Cooper S in GS, today, on a 100 second run will post a modified time of 82.1 seconds.

Next year when it moves 'up' to DS, it's time will be 81.9 seconds which means we'd actually have to be .200 seconds faster to beat the same car.

IMP

http://www.scca-chicago.com/solo/indexes/rtp2009.html

[QUOTE]This Index was developed by Rick Ruth and reflects study of results from over 200 nationwide Solo events including, the Tire Rack

Boyracer40

That's some good info. Thanks a lot. I suspected it might have something to do with the juggling of cars between classes, but wasn't sure.

If the Cooper S's presence in DS can change the future modifier number of the class as a whole, then those numbers aren't written in stone so to speak.

I was under the assumption that the numbers didn't change from year to year.

Thanks, again.

PedalFaster

The Stock classes aren't arranged in fast-to-slow order (for example, E Stock's a lot faster than D Stock), not is the speed differential between classes intended to be even.

PAX is an imperfect system, but it's fairly accurate, especially in the aggregate over several events. Our local region has about a dozen national-level drivers running in PAX class, and event after event most of them run within a half PAX-ed second of each other.

IMP

The reason PAX does a fairly good job, is that it draws from a rather large sample of events and regions that run on different surfaces, weather, and temperature.

Keep in mind, some cars will do better on concrete than asphalt and vice-versa. If you always run on high-grip concrete, then the cars that are top of pax at that location will be different than those from another location of loose asphalt.

It's an imperfect system to say the least, but it's a very good one.

That is correct. The beginning of every year brings the change in PAX with it.

I'm sure you're going to see a decent sized swing next year as Nats this year is Concrete (and for the coming years one can hope) as the *fast* drivers start optimizing their setups to run (and seek more) concrete again and sacrifice their speed on asphalt.

--kC

Boyracer40

[QUOTE=PedalFaster,Aug 24 2009, 06:56 AM]The Stock classes aren't arranged in fast-to-slow order (for example, E Stock's a lot faster than D Stock), not is the speed differential between classes intended to be even.

PAX is an imperfect system, but it's fairly accurate, especially in the aggregate over several events.

TheNick

FYI - the SCCA doesn't have anything to do with PAX. The Advisory Committee's and the SEB do not recognize anything Rick puts out as multipliers.


PAX is a result of the SCCA classing. Not the other way around.


Also, classing and PAX/RTP is done for the fastest cars in the class, on a National level. Local results very rarely play into anything that is done (except for large regions that have very fast drivers in multiple classes).


Its only your fault for not having the fastest car in the class. Such is the world of Stock classes, you have to be prepared to move on to the next car at a moments notice if you want to remain competitive.

Boyracer40

It's funny what you say about being prepared to change cars at a moments notice like it's changing a pair of socks.

one of my auto-x buddies made me laugh when he said being fast costs money. how fast do you want to go?

the CR is a $38,000 car. we're not talking nickels and dimes here. and that's without any mods.

i guess for some folks, if you gotta change cars, then you change cars.

i'm just not gonna be one of those guys. i'll take my 3rd place and go home happy.

IMP

Very few cars have been the top cars in a class for multiple years running. Every year, new cars come out that (can/might) challenge the current top cars in the class.

The forumla is this: Take a national champion caliber driver in a car that is fully prepped to the allowed rules. How will it do? Take for example the new Hyundai Genesis. What do you do with a brand new car like that?

You need hotshoes to drive the cars which means classing goes well beyond the price you paid and the power/weight ratio. It's about the 'performance potential in the right hands'.

There are $40K cars being beat by cars that cost a fraction of that. (See DS with the 3 series vs the 10+ year old TypeRs) in the same class.

Just because you paid $$ for your car doesn't mean you're guarenteed a win. You have to prep it, and be able to drive it. It's the latter that gives some people a bit of a problem, especially when someone shows up in a car that's 10 years old, cost $15k used, and puts $3-$4K into it and whips up on those that paid $50k for the car + mods.

--kC

alvanderp

And there is nothing wrong with that, but the fact remains that the PAX factors are based on the fastest drivers in the fastest cars for the class Nationally. And as Nick noted, they are a theoretical performance handicap managed by Rick Ruth with no affiliation with the SCCA. Is it widely accepted as an appropriate handicapping system by most all local regoins? Sure, but the SCCA does not sanction PAX, nor are PAX indexed classes in the SCCA rulebook. Therefore the associated classing committees do not take it into account when classing a particular car.