Classify your car for 2012

[pdy]

Also, it is worth emphasizing what Tom alluded to that HP to weight is not a very good ratio in general.
For the autocross, a lighter car will usually be much quicker than a more powerful one, given the same
HP/weight and similar other modifications. Butch does really well at autocross, but I'm lucky to even
be within 4 seconds of some of the same cars with similar HP/weight ratios at the big tracks.

[Cajundaddy]

Butch does really well at autocross, but I'm lucky to even
be within 4 seconds of some of the same cars with similar HP/weight ratios at the big tracks.

Which cars Paul? I don't think I have ever seen this happen.

[ttweed]

This game is all about wt/hp ratio and tire grip. Everything else is just window dressing.

I don't think this is entirely true, Dave. At AX, size matters far more than than at big tracks. Narrower, shorter wheelbase, lighter cars have a considerable advantage on tight courses. Higher power is somewhat neutralized, as there isn't as much time to put it down (shorter straights). Specific suspension setups to optimize transitioning/direction changes at low speeds make for an unstable car at high speed tracks. Aero effects go up with the square of velocity. While it is true that on equal tires at an autox, Kim's car and mine might be very closely matched, I am not at all convinced that this would be true on a big track. Unfortunately, we will never know what that difference might be under those conditions, as my '68 is not even legal for TT events, and I don't think I have the guts to drive it flat-out at big Willow with it's current setup. It is no fun getting loose in turn 8 at a buck-twenty. BTDT.

... it seems to me that the more modified a car, the less relevant is the age "rebate" on points. I wonder if we shouldn't have a reduction on that rebate as the modification points build.

That is an interesting and subtle point that no one has brought up before, Don, and we should keep that under consideration in reviewing results of both driving series this year. There have been definite improvements in suspension, chassis stiffness and aerodynamics, etc., in the Porsche model line over the years, but whether they are worth the number of points assigned under the rule is open to question.

It seems that we've also stumbled upon another issue with the new points system: the tire width points scale is absolute, rather than being scaled by weight.

Another good point that hasn't really been discussed or proven out in practice, Russell. It might be a little complex to add something like this into the base point formula, but worth keeping an eye on as we collect data going forward on the relative potential of light vs. heavy cars in the various venues.

For what it's worth, my feeling is that we missed the mark in our new rule set by not maintaining the two scales of mod penalties for AX vs. TT that GGR uses. The general consensus was "trust the HP/WT formula" over everything. As Paul and I are saying, this may not be possible or fair under the widely varying track conditions we experience in the full range of our events. To be competitive in both series, I really feel like I would need two different cars under our current rules, especially considering that we have now mixed all generations of Porsches into the same classes. YMMV. Personally, I resisted this radical change of the rule set from the beginning, advocating for rules stability and an evolutionary change process instead, but more adventurous minds prevailed, and now we have to deal with the new shortcomings we have created. I hope everyone will be patient, attentive, thoughtful and openminded during what will be a multi-year process as we sort this out, now that it is implemented. More of these kinds of ideas and careful consideration of the results from next year in all classes in both series will contribute to a very productive revision process next year, I'm sure.

TT

[Cajundaddy]

Tom you and I can agree to disagree on this and that is ok. What Don, Russell, Paul, you and I are all circling around is grip/weight. A light car with a lot of grip is quick on an AX course. This advantage is less on a big track but I have not seen any examples of cars on similar tires and similar hp/wt where the heavier car had a big advantage (4 seconds?). Perhaps you could find some examples of this. Really high HP#s are simply of little use in AX because there is not a long enough straight to utilize all of those ponies. Maybe part of the solution is simply higher points for weight removal. It looks like I can remove 300 lbs from my car now with very little penalty and run in the same class. This will result in a huge performance advantage at very little cost in points. Relative tire grip/weight, and cornering speeds will be much higher. Also under our rules as Don suggested the points rebate for older cars may be unnecessary. This is already accounted for with higher points for tire widths on heavier modern cars.

Bottom line: PCA-GGR developed a classing system that really does create a pretty level playing field for most cars under most conditions. In Zone 8 we still have a ways to go. So far it looks like light weight and soft tires are cheap, and wide tires and sway bars are expensive in terms of points. I do think the end result will be worth the pain but we are clearly not there yet.

[pdy]

Butch does really well at autocross, but I'm lucky to even
be within 4 seconds of some of the same cars with similar HP/weight ratios at the big tracks.

Which cars Paul? I don't think I have ever seen this happen.

Dave:

Compare me driving Butch to Mike Avitt in his GT3. He drove a superb lap at last Saturday's autocross, but I had TTOD at my previous two AX events.
At WSIR or Fontana, he is 3+ seconds faster than me. Maybe his HP/weight is a bit higher than Butch, but there is no way that Butch with 201WHP can
keep up with 340+ WHP on a big track no matter how light I make that car. At an autocross, where Butch is light and nimble, HP doesn't matter as much,
and I have a good chance. There are others who I can beat at an AX, but no way at a high-speed track, and the difference is big.

The point is that HP/weight is at best a crude measure of performance. At big tracks (TT), pure HP is dominant. For an autocross, it's grip-to-weight
as you and others have been pointing out.

I honestly don't know how to reconcile this given the 2012 rule set, but I have been thinking about it (as have many others). The older letter-class rules
and points assessments were maybe too coarse in their definitions, and maybe some needed adjusting. But that coarseness was probably appropriate
compared to the ultra fine detail we seem to be trying to determine with the 2012 rules.

I do know that nit-picking whether a car's base points should be 355 or 350 is pretty silly when the basic HP/weight tenet itself is flawed. A 3000 lb 300HP
Porsche will rarely have similar performance to a 2000 lb 200HP Porsche (the lighter car will have a distinct advantage at shorter tracks, and the more
powerful one will at faster tracks). Even trying to figure out 15 or 30 points on sway bars (for example) seems futile given this landscape.

Maybe I'll just shutup and drive, and we can sort this out later....

[Cajundaddy]

Hi Paul,
I don't know what you have under your hood but from our class calculator you would need about 265RWHP to be in a similar wt/hp class with a 996 GT3. If you had that kind of power I believe you could give a GT3 game on any track, anywhere as James Buck has regularly done with his car this year. Last April you were only 4/10ths off Mike Avitt at AAA Speedway. A very good result.

The GT3 shines on a long track like WSIR or AAA Speedway because they can put all of that power down. On an AX track the GT3 is at a disadvantage because it is rare to be able to use all that HP but he still has to pay points for the high power/wt ratio. In spite of this Mike Avitt has shown that top results are possible in AX as he is often found in the top ten and several TTODs with clean runs.

Yes, getting a new rule set is hard work and requires input from all interested drivers. If we listen openly, evaluate this input and compare it to actual results data we will get there... eventually.

[pdy]

Hi Paul,
I don't know what you have under your hood but from our class calculator you would need about 265RWHP to be in a similar wt/hp class with a 996 GT3. If you had that kind of power I believe you could give a GT3 game on any track, anywhere as James Buck has regularly done with his car this year. Last April you were only 4/10ths off Mike Avitt at AAA Speedway. A very good result.

Dave:

Butch has a slightly modified 3.0L, and dynos at 201 WHP. Weight about 2380 curb, 2450 with low fuel and me on board.
Yeah, 265 WHP would be sweet, but that's not in my budget.

Mike's GT3 had problems with fuel/throttle at Fontana in April, otherwise he would be 1:52s.

[ttweed]

Bottom line: PCA-GGR developed a classing system that really does create a pretty level playing field for most cars under most conditions.

Having not been involved with their program intimately, or knowing anyone who has, I will take this for granted. I'm sure they have their own group of "disgruntled" members who feel like their cars are unfairly treated, but perhaps it is smaller than usual. However, as I noted above, we did not adopt their total system, or maintain their dual classifications and mod penalties for TT vs. AX. A single car in their system runs in a different class for each venue. Not in ours. We are attempting a single classification system, adapting our old mod penalty scheme, without accounting for how differently certain mods can effect AX vs. TT performance. There are no less than 30 mod point penalties in their system which are different if you are classifying your car for AX vs. TT, spread out over the entire array of possible modifications--engine, suspension, weight removal, brakes, aero, etc.

A light car with a lot of grip is quick on an AX course.

This is true, but not the only factor, or the whole story, as I have mentioned. Let me illustrate my contentions with an example from my SCCA Solo experience in B-Modified class. The "car de jour" in that class is a D-Sportsracer, a car that is also road-raced in SCCA club and pro racing. In Solo (AX) racing, the dominant cars are the very narrow (48" track), short wheelbase (80"), obsolete flat-bottomed models from the past, outfitted with very specialized, low-speed aero aides (multi-element wings front and rear with foils optimized for ~40-70 mph speed range). The currently dominant road-racing DSR, the Stohr WF-1, has exactly the same HP/WT ratio as any DSR, but has a track width of 56", a wheelbase of 97", and a full ground effects underbody combined with a bi-plane rear wing with high-speed/low drag foils and a front splitter to develop downforce. Even though they might have the same power/weight ratio, even with equal tires, alignment settings and setups for each venue, the Solo DSR will absolutely destroy the Stohr on an AX course because it can negotiate tight turns, narrow gates, and multiple slalom cones without having to turn as much, carrying more speed everywhere by developing significant downforce without high speed. Conversely, the Stohr will be immensely faster on a road course, with greater stability from it's longer wheelbase, higher ultimate cornering speed from a wider track, plus lower drag and much more downforce at higher speed from its aero configuration. Even eliminating or equalizing the aero differences will still result in a several second margin for one over the other, depending on the venue. If you chose as an example the CSR and Formula Atlantic cars that are also eligible for B-Mod competition, the differences are even more extreme, because they are even bigger and wider than the Stohr. Many FA drivers have ended up boycotting B-Mod until SCCA does something to equalize performance with the smaller DSRs.

Granted, this is an extreme example, but it is indicative of the broadly different requirements for a fast AX car vs. a big track car. Size does matter--it is an oversimplification to say that "lightness and grip" are the only determining factors. Look at tire size as well. A very light car cannot even utilize a very wide tire on an autocross course--even with the softest of compounds, it might not be able to get enough heat in the tire in a single lap to optimize grip if the tire is too wide. But on a big track, with higher speeds and multiple laps, a larger tire can be advantageous. Then there's the issue of big brakes. On the big tracks, in multi-lap sessions, the last thing you want is to experience brake fade. Yet those big rotors and calipers are a handicap in AX, increasing weight and rotational inertia. I put big brakes on my old '73RS-look car after toasting the stock brakes at time trials, and I never suffered brake fade again, but I immediately lost a second on AX courses. I could go on, but it should be obvious that trying to use the same set of mod penalties to fairly classify a wide range of Porsche models in the same class for both AX and TT events is an exercise in futility, IMHO. We have a long way to go to make this scheme work well. In the meantime, we're supposed to be having fun with this racin' thang, so let's try to overlook the shortcomings in good spirits for the near term, and continue to improve the system we have adopted through cooperative discussion and objective analysis over the longer term.

TT

[JERRY B]

we're supposed to be having fun with this racin' thang, so let's try to overlook the shortcomings in good spirits for the near term

Tom you have 20-30 more horsepower and 650-750 less pounds than the 924/944 Cars in CC03 Don't expect a warm welcome, If you move there

[Cajundaddy]

Yeah, 265 WHP would be sweet, but that's not in my budget.[/quote]
No reason to upgrade the motor now Paul unless you choose to. When running on the same tires Butch is CC10 while the GT3 is CC12. You do not share similar power/wt ratios and you do not share a class. I would fully expect a car 2 classes higher in hp/wt to stretch it's legs a bit at Fontana or WSIR by a few seconds. No conflict here at all.

Tom,
Yes that is a pretty extreme example and I am not sure it translates well to our street Porsches that we AX and TT for kicks and grins. From our actual PCA results data, cars with higher power/grip/wt ratios consistently out perform cars with lower power/grip/wt ratios both AX and TT. Yes there are some subtle differences but both Paul and Mike have demonstrated that with a clean lap they can get it done in their class as well as overall. Just getting cars with similar performance in the same class is the goal for 2012. Big loopholes that allow drivers to game the rules should be avoided in the interest of fair play.

[ttweed]

Tom you have 20-30 more horsepower and 650-750 less pounds than the 924/944 Cars in CC03 Don't expect a warm welcome, If you move there

Where have I heard that before? Oh yeah, when I threatened to run my FP 911 in GP.
I guess I'll have to go to CC05 to keep everyone happy, Jerry.

OK, it's done. I won't change my adjustable front swaybar for next year and go to CC05. Classification site entry updated.

Doing my part for world peace,

[ttweed]

Paul and Mike have demonstrated that with a clean lap they can get it done in their class as well as overall.

We can agree on that.

The awful truth is that at our level of competition, it's more about the driver than the car.

TT

[Don Middleton]

...The awful truth is that at our level of competition, it's more about the driver than the car...

Once you really "get it", it's an awfully painful truth, for sure...but once you get over that, you can stop spending money on your car and, in the words of Paul Young and many others before me - JUST DRIVE!!!

[mrondeau]

My three step program for the new classification system.

Step 1 - classify your car
Step 2 - drive as well as you can.
Step 3 - see how you do at each event.

If you're driving as well as possible, you should be able to achieve satisfactory results at at least one or two events. All of our AX layouts are different and will reward some types of cars more than others. It is typically different at each event. All of our TT tracks are different and will reward some types of cars more than others (there's a theme here somewhere).

There is no way to equalize all cars for all tracks. At AAA Speedway, horsepower rules. At Chuckwalla and Streets, handling is more important. Buttonwillow is technical and takes some cajones to go fast. WSIR requires smooth inputs and lots of nerve.

The most important thing you can do to excel in your class is to improve your driving. Bill I., Steve G and Jad have all said the same thing to me over the past couple of years i.e. "There's always another 1/2 second out there." In other words, no matter how well you do, you can always do better.

It will probably take a few years to sort out the new system, so use the car classifier and go out and drive.

See you at the track

[Mmagus]

And with that in mind....I have done several variants of Tuffy set ups! I am enjoying the site just considering ways to run...even BEFORE driving!