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Last Post 30 Dec 2009 03:13 AM by  Andy Ucter
SMS PAX
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Andy Ucter
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17 Feb 2009 08:05 AM

    as some of you may know... PAX index vaules have been re-set for 2009.

    Due to the change.. SMS PAX should go to: .8515

    (average of STU: .836 and SM .867)

    quite frankly, I'd side a bit towards the STU side on this.. and set it in the T&S computer at .850

    rtp.rick
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    09 Dec 2009 09:21 AM

    With the PAX/RTP average increasing .004 to .006 (depending on what high or low one chooses to ignore), it seems as if .850 may be a bit low. Last year, FWR used .852. I thought that may have been too tough, but I think it should increase a little or, at least, stay the same, based on the other classes' increases.

    When I posted, I didn't realize that I was responding to an early 2009 post. None the less, what I said above still appears to apply.

    H's & K's,
    Rick Ruth

    Peppler33CS
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    09 Dec 2009 02:33 PM

    Rick, first thank you for your interest. This was addressed very late in last years offseason and yes, we settled on .852 for 2009 as it was simply a pure middle split between STU and SM. Assuming a 60 sec course, SMS had to beat STU by 0.96 seconds to equal PAX results. This made sense as you take a top STU Subaru or Evo and allow boost mods, bigger tires, unrestricted suspension, trick fuel, and heck engine swaps are allowed also, then that top STU car is going to be faster.

    I would propose that this goes to our board meeting for discussion so this is settled early in the year for 2010.

    If we kept the same formula (50/50 split of STU and SM), the resulting PAX index would be .860 (or .861 if you round up) and would require the SMS to run .99 seconds faster on a 60 sec course. With Rick's quick input in the message above, that may be a little too tough. I would suggest a 70/30 split between STU and SM, this would result in a PAX of .854 and would require the SMS car to run 0.6 seconds faster then STU on a 60 sec course. This is a .002 PAX increase over last year, where other classes have a .004 to .006 increase for majority of classes.

    Just my thoughts, but we need to make sure Indy agrees because we very well may have the class available for the National Tour in Peru again.

    rtp.rick
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    09 Dec 2009 03:40 PM

    .854 seems reasonable. That still may show to be too tough, though. Modifying the formula so that a .852 or .853 is achieved, may be more realistic. I don't recall anyone placing very close to the top (time wise) this past year (2009). I realize the class was new this last season and may become better developed but, as mentioned, no one seemed very close.

    EDIT: Because I've often been asked, I started paying a lot of attention to the relationship between "R" compounds and Street Tires. As I've mentioned many times before, I don't like this comparison because the variables are even more enormous than usual. That said, many Regions choose to apply a multiplier to the normal PAX/RTP factors so that they can apply a different factor to those cars fitted with Street Tires. The multiplier most often used seems to be .98 (or 98%). The regular factor is multiplied times .98 in order to achieved a "Street Tire Adjusted Factor". In my view (study), that number seems to be a bit tough. I have yet to see anyone (with suitable "R" compound competitors) come very close (time wise) to the top of any PAX results. I have been utilizing a .97 to .975 multiplier and have found that it helps the street tired cars enough to move them up the results, but still not over power any competitive "R" compound cars. If one were to split those multipliers and use .9725 as a muliplier, the SMS factor should be .853 (SM's .877 times .9725 = .853).

    H's & K's,
    Rick Ruth

    rtp.rick
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    10 Dec 2009 03:47 PM

    Bump

    I added additional information to my previous post.

    H's & K's,
    Rick Ruth

    Peppler33CS
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    15 Dec 2009 08:43 PM

    I'm sitting here wondering why I'm going to question the godfather of PAX ... but here it goes and personally, I really don't care what the final PAX number is.

    You are looking at it in terms of top-down (SM times some street tire multiplier), whereas I also look at it as bottom-up. I would look at a top level STU car, plus the addition of given allowances, and bench race the numbers. While I have no personal hands-on experience with STU (I drive the weenie miata), I would think you allow that STU car to run wider tires and allow for unchecked boost (those Rally cars can really be sooped up... see Chris Smith's RS converted to STI), allow for any additional suspension, brace, aero, and weight reduction allowances, that they infact should be at least 0.5 seconds faster than the STU car on a national style course. I'm just thinking, and maybe you have data that proves otherwise, but I'm just saying keep that mind along with the top-down approach and reach a happy medium.

    SMS in our region is coming along as there are a few cars starting down the path to be more competitive, but seriously if you take our top STU driver and slap a SMS sticker on his car he would still demolish the class. I can't say that since me, in my car, am consistantly still off the pace about 2 seconds on any given course that I should have a softer PAX. I need to drive better and prep the car to a national level. Allow me to slap on a turbo and run wider tires on my car and I'll be happy to take a .6 sec penalty :) (of course this has no bearing since the cars are total opposites).

    One note, I use STU as a benchmark because any STU car could run in SMS without any modifications. We obviously have a wide range of vehicles in SMS and it usually is a catch-all for the more modified cars that show up that may or may not be aware of SCCA rules. So while I harp on STU, it is a valid benchmark for a starting point for SMS.

    Like I said before, in the end we are probably discussing peanuts (.854 vs .852 or .853). And... why am I arguing with the godfather of PAX???

    wrheadle
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    16 Dec 2009 02:19 PM

    Looks like concrete favord the power cars. STU and SM PAXes made a significant jump from '09 to '10. looks like our SMS index will be .861 ==> (0.844 + 0.877) / 2 = .8605, rounding up to 0.861.

    Hmm.... let the poo stirring begin. :)

    Andy Ucter
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    16 Dec 2009 02:45 PM

    Andrew..

    Bare in mind that the purpose of PAX is to equate drivers from Class to Class. So take your best STU driver and throw him in a modestly prepped SMS car, compare times, and that should be your pax.

    Bill,

    Although your formula is spot-on, I think some further review is required.. Case in point.. Look at a known STU prepped car in your area, and compare that to say, Hoops BA EVO. huge difference.. IMHO far more than just averaging the two classes.. esp now.. after years of SM evolution and lack of restrictions versus all the lame STU restrictions.

    therefore, as I said in Feb, the local SMS PAX number should be a bit closer to the STU number.. We all know that tire has a far great effect on performance than raw power:weight..

    HOWEVER, I'e urged a couple people on the board that this be investigated, .... Just incase >:)

    Peppler33CS
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    16 Dec 2009 05:15 PM

    Chuck, I agree which is why I am in favor of a 70/30 weighted average towards STU (hence my proposed .854). Do you disagree with this proposal?

    Andy Ucter
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    16 Dec 2009 08:46 PM

    I do agree.. however, I must declare that I will be running SMS next year, therefore I am not allowing myself to make or help make / vote etc for any decision.. a bit of a conflict of interest..

    again, I will remind everyone, that because of this I have done more than my due dilligence talking to Jason (the new Solo Director) and Travis ( the new Ass-Regional Director) to assure this is resolved prior to the season opener.

    This is one of the items up for discussion at this weeks Solo Program Planning Meating.

    I will however, lend my logic-based opinions. I think somewhere in the 70/30 range is better

    10-11 points over STU is fair...

    I suggest we open with that, see how it goes, then adjust if needed.. just make it well known that the PAX # may change after the first two events. my method would be to take my first two event times in SMS at the .854 number, and adjust it to be .001 faster than 2nd PAX position.

    I'm not tooting my own horn, but feel that since I have been a consistant overall front runner from STU, (for three consistant years) going to SMS with the car modded slightly into SMS (lightweight flywheel, and wider Dunlops) SMS PAX should be pretty close to what I run.

    especially considering the HUGE difference between ST and STU (largest it's ever been, and I think, Rick, in all his invinite reason will scratch his head at that number sometime this year)

    Again, think of the top runners even nationally in SM, and my STU car (which was nearly fully prepped to the rules (still could have removed some weight, and gone to lighter brakes.. and more aero.)

    Huge difference.. take away the tire-width restriction, but keeping the SMS tire compound rule.. I think SMS is STILL closer to prep with STU.

    also note that this is coming from someone who ran both street tires and R-comps on the same car in the same weekend.. (did it twice last year) Even on old R-comps the car was considerably better just by swapping tires than it could have been throwing another 25ish % more hp at the car.

    Remember, since this isn't a national class... yet... we don't want to make this a $$$ class as SM has become. I don't see anyone willing or wanting to sink SM level $$$ into a local class car... I don't and I won't be.

    Peppler33CS
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    16 Dec 2009 10:24 PM

    Cool, I didn't realize you were changing classes. I guess we'll have strong data points starting next year... no more "bench racing" hehe. As for changing PAX, lets also wait until we hit a large concrete site (Peru) event.... either hosted by our region or another that you attend.

    Like I said before though, my comments are in no way an "offical" ruling as I'm just one guy voicing my thoughts and opinion.

    rtp.rick
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    17 Dec 2009 03:38 AM

    I'm sorry, I guess I don't get it. I thought SMS was a street tire version of Street Mod, not some altered version of STU (STU2 or STU+)? I offered a suggestion for what seems to work for comparing same classes shod with Street Tires vs. "R" compounds. If you're talking about something else, I guess I missed it. What 70/30 has to do with anything, I'm not sure. I guess I just don't understand what STU has to do with Street Mod. Oh, well. :-(

    H's & K's,
    Rick Ruth

    Peppler33CS
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    17 Dec 2009 05:33 AM

    SMS = SM on street tires.

    What should the PAX be? Well, it should be slower then SM and faster then STU. By how much? Last couple years it was split down the middle... this is probably too tough of a PAX. I am proposing a 70/30 weighted average (a number pulled from the air) so that the pax is closer to STU than SM. This results in a PAX of .854 You recommended a factor of .9725 to the SM PAX which resulted in a PAX of .853.

    It's two different ways to get to the same result. Whats not to get?

    rtp.rick
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    17 Dec 2009 06:37 AM

    STU has nothing to do with Street Mod. They should not be related in any way.

    H's & K's,
    Rick Ruth

    Peppler33CS
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    17 Dec 2009 07:59 AM
    I guess my point was SMS should be faster than STU.
    rtp.rick
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    17 Dec 2009 09:08 AM

    Peppler33CS wrote:
    I guess my point was SMS should be faster than STU.

    I have no arguement with that. :-)

    H's & K's,
    Rick Ruth

    bmonnin1
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    17 Dec 2009 10:46 AM
    rtp.rick wrote:

    Peppler33CS wrote:
    I guess my point was SMS should be faster than STU.

    I have no arguement with that. :-)

    H's & K's,
    Rick Ruth

    Just out of curiosity Rick, I was just looking at the 2010 PAX index and was wondering how you calculated the PAX index for SMF and STR since those classes did not run last year. I can see getting SMF by just looking at cars that were front drive running in SM but as far as I know there is nothing but maybe a few local regional classes like STR out there.

    rtp.rick
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    17 Dec 2009 11:48 AM

    There were several Front Wheel Drive Street Tire cars that could be checked on from all over the place.

    In St. Louis we had a well prepped and driven S2000 that was prepared to run STR (locally it ran BSP). In reality, more of the factor was theorized, more than data dictated, of course, that holds true for the Index in general. The factors are based on all kinds of data, but a straight math analysis is pretty useless.

    H's & K's,
    Rick Ruth

    wrheadle
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    17 Dec 2009 01:26 PM

    I think Rick has the concept right. SMS is a derivative of SM and the PAX should be as well. Where I struggle (and Rick hinted at this as well) is that we don't truly know what a fuly prepped SM car with the right street tires and a national caliber driver would fall. I also think it would be beneficial to have a conversation about SMS index with Indy, since they run the same class. If we want the class to have the best chance to grow legs and expand, we should be implementing it consistently across regions. It will work at the regional level without that, but if we want to set it up to grow...

    In the end, where the index falls needs to have a logical support argument behind it so we aren't going back and changing it every year (meaning it should float with the RTP/PAX). I have intentionally not said a value for the index because that is not what is important, rather the concept for calculating it is.

    Any changes to the index from what it was for 2009 will need to be presented to the Board of Directors as a change to the Policies and Procedures as SMS (SMT) is defined there under allowed classes at FWR Solo events.

    Rick-

    As a side note, the geek in me would love to know how you crunch the copious amount of data to come up with the new index each year.

    Andy Ucter
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    17 Dec 2009 02:21 PM

    yeah, uh, Bill, I'm going to have to go ahead and disagree with you there... /lumburg

    SMS isn't really a SM car on street-tires... regardless of it's designation..

    However, Rick does have the right concept in that SMS should be considered more an STU+

    you need to bear in mind what the limiting factor is.. Tire Compound. we don't get the band-aid of r-comps in any of the ST-classes.

    as an aside, I dunno where the SMT class designation came from.. but it is in the right spirit.. however, it should have gone to STM

    Street-Touring (read: Street-Tire) Modified.

    as far as methodology to determine an accurate SMS PAX number.. I've already given you that as well. Continuing, I've also talked to the powers that be in Indy region..

    As far as I am concerned, once we reach a definitive number, we can talk to INDY (would be glad to do it) for congruence.

    Again, let me remind you that my logic is from someone who has run both STU and SMS successfully in both FWR and Indy region. also, NORA, NWOR, Cincy, SBR, etc.

    Furthermore, it is the offseason, and these weird regional rules can and need to be adjusted asap... like i said, this stuff is up for discussion at the next solo planning meeting. I'm sure whatever is decided there will be brought up for a (...) vote at the next board meeting.

    using my aforementioned method.. it is the perfect test.. we'll know right away... when we have an overall front runner dropping in placement due to pax.

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