PCA SDR

As we get closer to the Z8 Committee meeting, I've been thinking about the proposal to switch to GGR Rules.

I don't think just swapping in their rules for ours is the best way to do it. Too many differences in how they think about things.
However, most of the complaints I've heard on the forum are not about the philosophy of the rules, rather they are nitpicking this or that points amount for one particular modification or another.

In the interest of research, I'd like to gather some data for a hybrid system. Assume we use GGR base points for your car model & year. Assume we use GGR class structure. But lets use Z8 handicapping rules for modifications, with the points magnitude adjusted to at least make a little sense. My initial thought is multiply by 10.

In other words, if you have 2 points for sway bars, make it 20. 4 points for weight reduction, make it 40, 6 points for horsepower, make it 60, etc. Take your Z8 points and multiply by 10. If you are carrying 8 pts in Stock, make it 80, 20 pts in Prepared, make it 200.

This may not work out at all, but I'd like to see the results, just for research's sake. If you can email me your name, base points and modification points (based on this "hybrid" system), say by Monday, Labor day -- I can consolidate and post the resulting hypothetical "class" list for comment. I'd also appreciate it if you sent me a filled out tech sheet so I can see how everybody gets where they land. Obviously you can post your response here as well, but please email to: tb911@tbsoftware.net

It may not be where we end up, but at least it is something to think about and may help us get there.

thanks

Ok, only three of you responded to my call for data. After 12 pages of these discussions about this back in July, I'd hoped for more interest.

Doesn't mean I could play with the numbers, but it does mean I need to make some assumptions.
First of all, for base points, here are a couple of examples of assumptions I needed to make. I couldn't always tell from our results database if a 911 was an S, E or T, so I just assumed middle of the road. Similarly for C2, C4, C2S or C4S, couldn't always tell. For modification points, I assume everybody is maxed out in class. 6, 8, 20, 40, etc. except for AR2 I just assume 84 points, since there is no max.

Back to my experiment. As I said, most people like the idea behind the GGR rules, but seem to dislike how they handicap modifications. So my thought was use our "tried and true" or at least "familiar" modification handicapping scheme. Meaning we'd use GGR base points for cars and then add handicapping points according to our Z8 rules schedule of points.

The problem is, of course, that the base points are up in the hundreds but our handicapping points are multiples of two. So they need to be scaled, but the question is "how much"?

If you look at this webpage: http://www.porscheclub.us/hybridrules.php

You will see two examples, AX & TT, each with 5 different scaling factors (5, 7.5, 10, 12.5 & 15). I have two examples because there tend to be somewhat different players between the two types of events.

So that you are clear about what is going on:

GGR Base Points + Z8 Points * Scaling factor = New Classification Points.

Some other tidbits: I used the GGR Time Trial base points for both, that is, I did not use the AX base points (they are mostly the same, and generally lower for TT when there is a difference). However, I did use the different points schedules for classes between the two types of events. So the break between classes, starting with TT5 & AX5 is different at the higher class levels. I'm also ignoring the GT classes, just using the TT classes for Time Trials. See the GGR Rules at http://comp.pca-ggr.org/classification_2010/web/car_classes.php

My assignment for you is: Look at these 10 different groupings and tell me which ones you think are most fair. Which classes are the most fairly balanced according to who is competing with whom. In other words, which scaling factor would you recommend if we were to do something like this?

If we do adopt a new GGR style system, I hope it goes with out saying it won't be 100 percent right out of the box, won't be perfectly fair to all. But then again, our current system is 20+ years old and after 20 years of changes, it still isn't perfect (and some say getting worse).

Please let me know what you think by Thursday, as the rules meeting is Saturday.

Thanks for your input

Ok I'll play. 7.5 mod multiplier looks pretty close to me for both AX and TT. GT3s look about right and the Cayman/Boxster/Spec944 look like they are well grouped. I know very little about the performance envelope of the light and highly modded early cars... except that they are faster than mine.

Tom, that's a lot of work.

I like the 12.5 AX multiplier, Gives a good class structure with a nice diversity of cars in each.
Seems it's hard to avoid a mega class in any scenario.

Tom, one problem with this approach is that the Zone 7 base points do not include points for wheels/tires. These are added on in addition to the base points for wheels wider than 6 inches.

"If the car has wheels that are wider then 12 in. total (one front wheel + one rear wheel), then additional wheel points will be assigned at a rate of 10 points per half inch above 12 in. Example, a car with 8 in. wide front wheels and 10 in. wide rear wheels has 6 in. (or twelve half-inches) of extra wheel width above 12 in., so it would be assigned 120 wheel points (10 points x 12 half-inches)."

This is linear and has no maximum, as opposed to our present "flawed" system that maxes out at 4 points for increased tire width. A 914 going from 165mm stock tire to a 325mm (or even larger) tire would have the same 4 points that a 911 SC going from 205 to a 255 tire would have.

I think you need to look at this in your calculations. One option similar to the Zone 7 would be to give everyone a 205mm base tire front and rear and then for each mm over that you would add a point.
If you had 225 mm front and 245 mm rear tires, you would have 60 points (225-205=20 + 245-205=40 = 60 total points). Like Zone 7 it would be linear and without a maximum. Wider tires will cost you more points.

Most of the newer cars would have around 100+ points added to their base for their larger stock wheels.

Greg

One option similar to the Zone 7 would be to give everyone a 205mm base tire front and rear and then for each mm over that you would add a point.
If you had 225 mm front and 245 mm rear tires, you would have 60 points (225-205=20 + 245-205=40 = 60 total points). Like Zone 7 it would be linear and without a maximum. Wider tires will cost you more points.

Most of the newer cars would have around 100+ points added to their base for their larger stock wheels.

I like this option, Greg.

As far as a hybrid system goes. Why not use our point system and a classing system like zone 7s?

But then again will that give us less classes? Which is the point of all this as I recall.

In my opinion and focusing on the hybrid TT tables Tom has created, anything ABOVE a 7.5 multiplier for our modifications would be totally ridiculous from the competitive standpoint. Just look at the resulting car pairings and the TT results we have had and you will have to agree, particularly when comparing cars that are currently competing with the max points for their Z8 class as Tom shows in his tables. Somewhere between a 5 and a 7.5 multiplier would be more reasonable and the way to go if at all. Otherwise I would rather have the full set of Zone 7 Rules as they stand today.

Believe me when I say I seriously appreciate all the hours of work that many including Tom have put into rating and classing our cars. I have been involved in rating and classing rules in other sports before and it is surely a difficult and thankless job. Thank you Tom et al for all of your efforts in this. I hope I can help to make your job easier.

Is it possible that we are over-thinking all this. Doesn't 98% of this game we play really come down to power/weight ratio, available grip, and driving skill, leaving 1% to car balance, 1% to aero in Time trials? It seems that most other sports car organizations are moving this way including Grand Am, ALMS, NASA, SCCA, (other than prototype classes which rely on very significant aero enhancements).

Just thought I'd throw that out there. Often the simplest solution is the most workable solution.

Cajundaddy wrote:Believe me when I say I seriously appreciate all the hours of work that many including Tom have put into rating and classing our cars. I have been involved in rating and classing rules in other sports before and it is surely a difficult and thankless job. Thank you Tom et al for all of your efforts in this. I hope I can help to make your job easier.

Is it possible that we are over-thinking all this. Doesn't 98% of this game we play really come down to power/weight ratio, available grip, and driving skill, leaving 1% to car balance, 1% to aero in Time trials? It seems that most other sports car organizations are moving this way including Grand Am, ALMS, NASA, SCCA, (other than prototype classes which rely on very significant aero enhancements).

Just thought I'd throw that out there. Often the simplest solution is the most workable solution.

Hey Dave, I had been thinking the same thing. Then, I realized that those other organizations are dealing with fully prepared race cars. They can create a few classes and be done. We are trying to classify cars with various levels of preparation from street stock to full race. We need 10-20 classes to make it competitive for the virtually unlimited number of possible configurations.

Tom, hang in there...

Greg Phillips wrote:Tom, one problem with this approach is that the Zone 7 base points do not include points for wheels/tires. These are added on in addition to the base points for wheels wider than 6 inches.

"If the car has wheels that are wider then 12 in. total (one front wheel + one rear wheel), then additional wheel points will be assigned at a rate of 10 points per half inch above 12 in. Example, a car with 8 in. wide front wheels and 10 in. wide rear wheels has 6 in. (or twelve half-inches) of extra wheel width above 12 in., so it would be assigned 120 wheel points (10 points x 12 half-inches)."

This is linear and has no maximum, as opposed to our present "flawed" system that maxes out at 4 points for increased tire width. A 914 going from 165mm stock tire to a 325mm (or even larger) tire would have the same 4 points that a 911 SC going from 205 to a 255 tire would have.

I think you need to look at this in your calculations. One option similar to the Zone 7 would be to give everyone a 205mm base tire front and rear and then for each mm over that you would add a point.
If you had 225 mm front and 245 mm rear tires, you would have 60 points (225-205=20 + 245-205=40 = 60 total points). Like Zone 7 it would be linear and without a maximum. Wider tires will cost you more points.

Most of the newer cars would have around 100+ points added to their base for their larger stock wheels.

Greg

Greg,

To clarify, are you suggesting that our 2 or 4 points is insufficient handicapping for tire width and that whatever we do this must be changed, whether we keep our current system or switch to GGR's or do anything in between or even totally different? My wild idea here is meant to be a discussion point, a compromise idea for those that want fewer classes and like the GGR way of classifying cars vs. those that don't like the GGR way of assigning points. If you don't like the way we currently handicap tire widths, that really is a separate issue, and isn't related to how those points ultimately affect your car classification. As I've said, whatever we do will not be perfect and I'm sure will require lots of future tweeking to correct bits of unfairness here and there over the next 20 years, just as our current system has kept us occupied for the last 20.

That being said, I have noticed that our system of applying points places modified older cars at the same disadvantage as in the "normal" GGR system. Ultimately the points from modifications play a larger role in your classification than does your base model, which means that older cars are competing with newer cars that seemingly should be much faster. Perhaps your idea about tire width is a step to fixing this problem?

Yes, there are related issues regarding tire width.

If you are looking at our rules, the present points for tire width are inadequate for the wide variation in tire sizes/wheel widths. They should be changed. One of the attractions of the GGR rules is their handling of wheels/tires points.

If you are looking at the Zone 7/GGR rules, using only the base points does not adequately measure the performance potential of later models with larger tires/wheels.

You need to add the tire/wheel points to the base points before adding the modification points. The larger wheels and tires are not factored into the base points but have a large impact on their performance potential.

I am not sure a hybrid system might not bring the worst of both worlds, rather than the best of both
The attraction of GGR is using a full tested system. Trying to patch it without testing it might not be in our best interests.

Greg

Here is the tally

1 for 5x via email
1 for 7.5x above
1 for 12.5x above
1 for 5x or 7.5x above

Not a lot of feedback, so far, except to say the trend, if you can call it that, is for a lower scale factor

Greg Phillips wrote:I am not sure a hybrid system might not bring the worst of both worlds, rather than the best of both
The attraction of GGR is using a full tested system. Trying to patch it without testing it might not be in our best interests.

Greg

But is it more familiar and therefore more acceptable to our membership?
If you read the feedback, some people want to patch it from the get-go, don't like the way it does or doesn't assign points.
Just because it is "tested" by GGR doesn't mean it will work for us. And what does "work" mean anyway -- what level of event entrant complaints about something makes the difference between working and not working?

I would suggest using the GGR system as is and making small adjustments from that as needed rather than "patching" the system and then making adjustments. It will take a year or two just to figure out how the system is working for us anyway. This would make it easier for the rules committee, give us a baseline to start from, and give everyone a chance to try out a slew of new excuses for why they woulda, coulda, shoulda gone faster

What do I know? I drive a 944. It may not even be a real Porsche! But, I do drive "Flat Out".

I don't suppose anyone has ever considered actually talking to the GGR people to find out what issues they have and what they would do to change their system if they could start over?
Just my $.02