Thoughts on the weight points in 2012 rules

[ttweed]

There are 2 different formulas in the proposed 2012 rules that use weight as a factor: the 4000/PW formula for 'base points', and the section X "removal weight * .4" formula. I don't think they are compatible.

Yes, there are two places where the weight of the car comes into play in the existing 2012 rule set, but they are not the same thing and they are perfectly compatible. The "base points" formula takes into account the STOCK weight for the model car (based on the published table). The second formula is for modified cars, where weight has been reduced more than 50 lbs. from the stock weight. It is a MODIFICATION penalty. Two different things. The GGR system has point penalties for every individual weight reduction mod--strip the interior, take points; add fiberglass where there was steel, take points; race seats rather than stock, take points; lexan rather than glass, take points, etc. We did not adopt their extensive weight reduction penalty scheme, but substituted a form of our old weight reduction modification rule. There is no provision for having a separate base point P/W calculation for EACH INDIVIDUAL CAR entered in the event--that is done by model type as a group--so without a weight reduction penalty, you could end up running your stock car against a similar model stripped-out race car.

What Greg is proposing is using a separate P/W calculation done for each individual car to determine this weight penalty, as well as possibly the engine mod penalties. I agree with you--if we are going to go to that length to determine mod points, we might as well just dyno every car, weigh it, and assign the base points individually, based on the determined power/weight ratio, and eliminate all engine mod and weight penalties entirely. That is exactly what is done in many race series. Unfortunately, this is an extraordinary effort and expense to go to for an autox series w/ prizes of a 50-cent ribbons and a $10 trophy at year end, as Dan has said, and difficult to establish and enforce.

TT

[Greg Phillips]

There are 2 different formulas in the proposed 2012 rules that use weight as a factor: the 4000/PW formula for 'base points', and the section X "removal weight * .4" formula. I don't think they are compatible.

Yes, there are two places where the weight of the car comes into play in the existing 2012 rule set, but they are not the same thing and they are perfectly compatible. The "base points" formula takes into account the STOCK weight for the model car (based on the published table). The second formula is for modified cars, where weight has been reduced more than 50 lbs. from the stock weight. It is a MODIFICATION penalty. Two different things. The GGR system has point penalties for every individual weight reduction mod--strip the interior, take points; add fiberglass where there was steel, take points; race seats rather than stock, take points; lexan rather than glass, take points, etc. We did not adopt their extensive weight reduction penalty scheme, but substituted a form of our old weight reduction modification rule. There is no provision for having a separate base point P/W calculation for EACH INDIVIDUAL CAR entered in the event--that is done by model type as a group--so without a weight reduction penalty, you could end up running your stock car against a similar model stripped-out race car.

What Greg is proposing is using a separate P/W calculation done for each individual car to determine this weight penalty, as well as possibly the engine mod penalties. I agree with you--if we are going to go to that length to determine mod points, we might as well just dyno every car, weigh it, and assign the base points individually, based on the determined power/weight ratio, and eliminate all engine mod and weight penalties entirely. That is exactly what is done in many race series. Unfortunately, this is an extraordinary effort and expense to go to for an autox series w/ prizes of a 50-cent ribbons and a $10 trophy at year end, as Dan has said, and difficult to establish and enforce.

TT

No, my proposal is only to determine penalty points for weight reduction in cars.

If you have a stock car, no need to calculate weight reduction points. But if you have taken weight out, you will need to get it weighed and determine what the actual weight is, which is also required of our current rules. You need to weigh your car with either system, the only difference is how your points are determined.

1-Using the same formula you used to determine the classes utilizing power to weight. Your penalty is determined by the difference between your stock PW and your improved PW with the decreased weight
2- Or you use a one-size-fits-all of 10 points for every 25 pounds,not counting the first 50 pounds or the spare, tools, passenger seat etc. 100 pounds in a 914 costs you the same as 100 pounds in a Panamera (or 928)

Greg

PS I have not mentioned dynoing cars for classification, although I did point out that using the PW formula could also be used for STOCK engine swaps to calculate penalty points for the increased power.
Again, the increased potential for a given engine swap is not merely the added horsepower, but what effect it has on the PW ratio. An extra 100 HP in a 914 will have a greater impact than an extra 100 HP in a Panamera (or 928). If you believe in the concept of power to weight as a major factor in performance (I do), it makes sense to use it where feasible.
GP

[Mmagus]

If you have a stock car, no need to calculate weight reduction points. But if you have taken weight out, you will need to get it weighed and determine what the actual weight is, which is also required of our current rules. You need to weigh your car with either system, the only difference is how your points are determined.

Greg and all,

This is exactly what I have been trying to point to. (underlined and bolded not due to being upset, but for clarity.)

If we weigh a car to see if points need to be taken, what weight do we then compare it to in order to make the determination? If we use the current GGR based number we could get a false result as it is 81 pounds heavier than the owners manual.

I have removed weight, for the sake of discussion lets say it came to 50 lb on the nose. If we are following the GGR number and its wrong, and the manual correct when we weigh the car I would have to take points for 81 pounds that never existed.

Mark

[gulf911]

Seriously guys, if you are going to go through the trouble of weighing the cars you might as well dyno them as well (+1 Tom) and do away with all the other point BS. If your car is heavier than Porsche's specs show I would be trying to figure out why, especially if is 80+ pounds. Just a shot in the dark here, but maybe ask GGR how they came up with the number? If you guys are going to quibble over +/- 50 lbs then they need to be weighed coming off the track after timed runs.
It is obvious with any system you aren't going to please everyone. And I can see tweaking coming, just like the old system. Why did we change again?

[Mark Garriott]

Weight is weight and horsepower is horsepower. And, it all comes down to pounds per horsepower -- which is the primary determinant for classification. There should not be 2 scales -- one for the weight Porsche bestowed upon the stock car, and another for weight removed from the car by the owner.

If I enter a lower weight into the 4000/(weight/horsepower) formula, I wind up with a high power:weight ratio, and I wind up with more points. The modification penalty is built in to the equation. And, the modification penalty is consistently applied across all cars, no matter what the stock weight or horsepower is.

Take 2 nearly similar cars -- 2011 Cayman S and Boxster Spyder. Both have the same HP, but the Cayman is 165 lbs heavier.

The Cayman S is assessed 430 points worth of lbs/hp.
The Boxster Spyder is assessed 455 points worth of lbs/hp.

We see the Spyder gets an additional 25 penalty points, because the factory 'removed' 165 lbs.

However, if I were to remove 165 lbs from the Cayman S to make it match the Spyder, I have to apply the modification penalty -- 165 * .4 = 66 penalty points. (Let's assume the cupholders, tool kit, jack, & 8-track tape deck have all been removed from both cars to account for 50 lbs of slop)

Why is the additional penalty for weight removed by me MORE THAN DOUBLE the penalty for weight removed by the factory? The cars have the same power-to-weight ratio after the modification.

[Greg Phillips]

If you have a stock car, no need to calculate weight reduction points. But if you have taken weight out, you will need to get it weighed and determine what the actual weight is, which is also required of our current rules. You need to weigh your car with either system, the only difference is how your points are determined.

Greg and all,

This is exactly what I have been trying to point to. (underlined and bolded not due to being upset, but for clarity.)

If we weigh a car to see if points need to be taken, what weight do we then compare it to in order to make the determination? If we use the current GGR based number we could get a false result as it is 81 pounds heavier than the owners manual.

I have removed weight, for the sake of discussion lets say it came to 50 lb on the nose. If we are following the GGR number and its wrong, and the manual correct when we weigh the car I would have to take points for 81 pounds that never existed.

Mark

You would compare your weight to the weight that was used to calculate your basepoints.

People are hung up on the accuracy of the weights used by GGR. What makes you think the owner's manual is any more accurate? I would bet that you could take 100 brand new cars off the dealer's lot and if you weighed them, none would be exactly the listed curb weight

It is a weight that will be close to the car's actual weight, but that is all. Again, whatever the weight your car was assigned to calculate the basepoints is the important weight.

If we ASSUME the owner's manual is the more accurate (not right or wrong) weight, then everyone's basepoints calculation would need to be adjusted (if the change is large enough), I will let you do the calculations.

If you choose a lighter weight, your basepoints would go up and if you choose a higher weight, they will go down IF the change is significant enough.

Greg

[Mark Garriott]

I see no need to require dynos or scales. Go by best guess. If all you have is the PCNA chart? Use it. Owner's manual? Use it. Actual dyno & scale data? Use it.

All I am arguing for is to be allowed to run whatever data I have through the same formula that factory/stock data is run through to determine power/weight points.

[Mmagus]

Greg.

I am not trying to be frustrating. I really try my best to treat others fairly in life and that is the case here. I am trying to be fair, mainly to my competetors as I will get probably get dinged if the weights are changed for my particular car. As you mentioned.

I'm sorry if I caused you or anyone else any grief. You all figure it out and tell me where I stand.

I'll just drive.

[Jad]

Good thing we all know our exact HP and the weight is the only variable

Or at least a dyno run would quickly clear up that issue without question or variance.

Get somewhere close to equal competitors and enjoy, don't worry about 50 lbs, 50 points or 50 hp, a good drive can easily overcome any variation of this size.

I think a nice, clean, simple, stable rule set is far better than going for perfect equality. I really like the new rules as they tell you ABOUT who you should be competing against, so go compete against them

[rshon]

If you look at the class line-ups from last month's Time Trial, some of the car match-ups make sense, some are out of whack (independent of who is driving or how they did). Those of you who know the cars know it's true. The current points system clearly penalizes engine swaps too much, sticky (<50 TW) tires and chipped turbos too little, IMHO (the old points system also had these problems, but the new modification points scaling has actually made it much worse).

There is no question that whatever the points system, a clever and well-heeled competitor can choose the advantaged car and the underrated mods and put together the most capable car the rules will allow. But not all of us are inclined or in a position to do that. It's hard to conquer the world when it keeps moving around...

[Cajundaddy]

Get somewhere close to equal competitors and enjoy, don't worry about 50 lbs, 50 points or 50 hp, a good drive can easily overcome any variation of this size.
I think a nice, clean, simple, stable rule set is far better than going for perfect equality. I really like the new rules as they tell you ABOUT who you should be competing against, so go compete against them

+1
Within 50 lbs, 50 pts, 50 hp = one sloppy corner and is plenty close enough to have fun and play without suffering an anxiety attack over rules issues. When Ferrari calls us up to Formula 1 we will get more specific

From my perspective we need to look at tire point adjustments, clean up a few errors with P/W ratios and motor transplants and we have a winning rule set for 2012. It will never be Formula 1 exact... thank goodness, but it will be fun and fair for the vast majority of drivers.

[Jad]

Get somewhere close to equal competitors and enjoy, don't worry about 50 lbs, 50 points or 50 hp, a good drive can easily overcome any variation of this size.
I think a nice, clean, simple, stable rule set is far better than going for perfect equality. I really like the new rules as they tell you ABOUT who you should be competing against, so go compete against them

+1
Within 50 lbs, 50 pts, 50 hp = one sloppy corner and is plenty close enough to have fun and play without suffering an anxiety attack over rules issues. When Ferrari calls us up to Formula 1 we will get more specific

From my perspective we need to look at tire point adjustments, clean up a few errors with P/W ratios and motor transplants and we have a winning rule set for 2012. It will never be Formula 1 exact... thank goodness, but it will be fun and fair for the vast majority of drivers.

+1 Excellent point, look at rear diffusers and flexible front wings.... Wait, you mean they are writing the rules with a multi-million dollar budget, for one pretty exact spec of car, for 1 year, 1 series and they can't even reach perfection

Fix the big issues, keep it simple and play nice with whoever is grouped SIMILAR to you!

[ttweed]

Weight is weight and horsepower is horsepower. And, it all comes down to pounds per horsepower -- which is the primary determinant for classification. There should not be 2 scales -- one for the weight Porsche bestowed upon the stock car, and another for weight removed from the car by the owner.
[snipped]
Why is the additional penalty for weight removed by me MORE THAN DOUBLE the penalty for weight removed by the factory? The cars have the same power-to-weight ratio after the modification.

OK, now I understand what you're saying, Mark, and it is basically the same idea that Greg is proposing. You are talking about "equity" rather than "compatibility," which threw me at first. It is perfectly "compatible" with our goal of leveling cars that our rules contain a provision for penalizing weight reduction from stock, but the question is whether our existing formula is "equitable," and I agree with you that it isn't, for a number of reasons. What Greg has said is this:

For the weight points, decreasing the weight would only change the PW or power to weight ratio, so the difference between the basepoints and the greater points with a better PW number would be your weight points penalty.

The devil is in the details in writing this kind of rule, though. The problem I see with Greg's proposal above is that it relates the weight point reduction to the difference between your new PW ratio (after weight removal) and the assigned base points for your car, not with the original "stock" PW ratio. This ignores the adjustments for age and tire width that are also included in the base point calculation, unfairly penalizing older cars, which receive a reduction in base points based on age and "design and performance advantages inherent to models that were engineered to utilize wider wheels" (which could also be expressed as "engineering advances in suspension/chassis design in later model cars"). The penalty should be calculated by comparing stock PW ratio and modified PW ratio only (unrelated to base points), IMHO, and be written in a way that is clear and easy to calculate. This is easier to say than to do. Nevertheless, I would suggest a proposal something like this (using your example of a Cayman S):

Existing rule:
X. Weight of the car below the base car curb weight:
The first 50 pound reduction in weight is zero points, beyond that points are determined by multiplying the reduction in weight by .40 and rounding up to the nearest multiple of 10.
Example:
Decrease in weight: 85 pounds
85-50 = 35
35 x .40 = 14, rounded to 20 points.
Curb weight is defined as the weight of the base car as listed in the chart in Section XVIII Appendix C. If the chart gives a weight range, for purposes of this section, the lowest weight should be used. For weighing, the car should be ready to drive with all fluids (gas, oil, etc) full, tools, spare tire, jack, etc in the car but no driver. These items do not have to be in the car or fluids full while participating in the event. Anything removed for purposes of Section XIII Part M may be replaced and all fluids may be topped off, as needed, before weighing.

Proposed new rule:
X. Weight of the car below the base car curb weight:
Penalty points are determined by calculating the difference in power to weight ratio achieved by the removal of weight according to the following formula:
[4000 / (ModifiedW/P)] - [4000 / (StockW/P)]

"StockW" is defined as the curb weight of the base car as listed in the chart in Section XVIII Appendix C. "P" equals the Horse Power for the base car as listed in the same chart. "ModifiedW" is the weight of the car as measured after modification. For weighing, the car should be ready to drive with all fluids (gas, oil, etc) full, tools, spare tire, jack, etc in the car but no driver. These items do not have to be in the car or fluids full while participating in the event. A discrepancy of 50 lbs. in total car weight is allowed to account for differences in scale weight calibration at varying locations.

Example:
165 lbs. have been removed from a 2010 Cayman S (determined by weighing the car per procedures above and comparing it to the listed Curb weight). The penalty points for this modification would be:
[4000 / (2811 / 320)] - [4000 / (2976 / 320)]
resolved as:
(4000 / 8.78) - (4000 / 9.3)
or
(455 - 430) = 25 point weight modification penalty

This matches your example exactly, Mark. I would note also that this does not address which figures are finally adopted as the proper "Curb weight" for the appendix chart, the existing "PCNA table" or owner's manual data or a revised table of our own making, nor does it address the question of whether the weights should be taken including driver, which I would prefer. I also thought the statement: "Anything removed for purposes of Section XIII Part M may be replaced and all fluids may be topped off, as needed, before weighing" was redundant, so I left it out. The "free 50 lb. allowance" does not enter into the calculation directly, but is retained indirectly as a "slush" factor. My experience has been that scales commonly used to weigh a 2-3,000 lb. car can easily have a tolerance of +/- 50 lbs. as far as accuracy is concerned. Nobody should get bit in the butt because the scale they used was reading heavy by 50 lbs. That's only a 2% error in a 2500 lb. car. I didn't put any language in regarding "rounding up or down" or how many decimal points the figures should be carried out to in making the calculation, but this isn't rocket science--it should be close enough for our purposes.

Comments, criticisms, and suggestions welcome.
TT

[Greg Phillips]

Tom wrote:
The devil is in the details in writing this kind of rule, though. The problem I see with Greg's proposal above is that it relates the weight point reduction to the difference between your new PW ratio (after weight removal) and the assigned base points for your car, not with the original "stock" PW ratio. This ignores the adjustments for age and tire width that are also included in the base point calculation, unfairly penalizing older cars, which receive a reduction in base points based on age and "design and performance advantages inherent to models that were engineered to utilize wider wheels" (which could also be expressed as "engineering advances in suspension/chassis design in later model cars"). The penalty should be calculated by comparing stock PW ratio and modified PW ratio only (unrelated to base points), IMHO, and be written in a way that is clear and easy to calculate. This is easier to say than to do. Nevertheless, I would suggest a proposal something like this (using your example of a Cayman S):

I was not clear enough in my formulations, it does get confusing. I think we are looking at the same formula, I was loose in using basepoints terminology.

For weight reduction penalties, it would be the difference between 4000/PW (stock weight*) and 4000/PW (lightened weight). In my example using the SC I mentioned disregarding the rest of the formula, only in the sense that it would be the same for both calculations.

On page 1 I wrote:
What I have been looking at for a proposal for 2012 would be to utilize the same formula for basepoints to determine your weight modification points.

Instead of using the PCNA weight, you would use your own (lower) weight in the equation and the difference between this number and your model's basepoints would be your modification points.

Greg

[ttweed]

I was not clear enough in my formulations, it does get confusing. I think we are looking at the same formula, I was loose in using basepoints terminology.

For weight reduction penalties, it would be the difference between 4000/PW (stock weight*) and 4000/PW (lightened weight). In my example using the SC I mentioned disregarding the rest of the formula, only in the sense that it would be the same for both calculations.
On page 1 I wrote:
What I have been looking at for a proposal for 2012 would be to utilize the same formula for basepoints to determine your weight modification points.

Instead of using the PCNA weight, you would use your own (lower) weight in the equation and the difference between this number and your model's basepoints would be your modification points.

Ya, I figured I knew what you meant, but saying "difference between this number and your model's basepoints" in the last sentence was the problem for me--it's not precise enough. You can't subtract the mod PW calc from the total basepoints for the car, which includes the adjustment factor, and be fair. The PW calc is just one part of the total basepoint formula, but it is all that is needed for figuring the mod points. The second part of the basepoint calc is an adjustment factor, and can add or subtract points according to the car model, according to age, suspension/chassis improvements, and engine location (plus other opaque factors of "performance potential" that are not spelled out). Early cars have points deducted from the PW calc, and later cars have points added. If we are going to keep the calculation simple and treat mods equally throughout the model ranges, we can't include the adjustment factor that is made after the PW formula in the mod calculation. Once you figure the mod points from the PW comparison, if you subtract that from the model's basepoint total, you get a distorted number that is not equal across all models because of the adjustment portion of the basepoint total.

For instance, my '68 911 has a PW calc of 18.27. Dividing 4000 by this number equals 219, not the 170 total basepoints that are assigned. There are 49 points deducted from the 4000/PW calc because of age and the fact that it has an archaic torsion bar suspension and can't fit wider than a 205 tire on skinny rims with its narrow body. Compare this to a newer model like the 2010 Cayman S, which has a PW calc of 430 (as Mark G. stated above) yet a basepoint total of 475. It has 45 points added to its PW number to reflect its newer suspension/engineering and the ability to fit 8 & 9" rims, along w/ 25 points for mid-engine location. If you subtract the mod point penalty as calculated without this adjustment factor from the total basepoints, which includes the adjustment factor, you skew the result in favor of newer cars (which have adjustment points added) and to the detriment of older cars (which have adjustment points deducted to determine the total basepoints). To treat each model equally, you need to ignore the adjustment portion of the basepoint total in calculating the mod penalty. You don't subtract the car's total stock basepoints from the modified PW points, as that includes the adjustment factor on only one side of the equation, but simply subtract the stock PW calc from the mod PW calc to determine the point penalty, which is then added to the stock base points to determine the car's class.

I think this is a fairly simple, elegant and fair method for determining the weight penalty, which makes it proportional to the cars total weight, rather than proportional to the total weight removed (which is how it is now and obviously unfair), eliminating the advantage gained by removing the same amount of weight from a very light car as opposed to a very heavy car. It makes the percentage of weight removed the determining factor rather than the total weight removed.

This same method can easily be applied to the stock engine swap situation, as you suggested, and I will start another thread for that proposal.

TT