Weight Sticker - Weight Penalty for Brakes Question

ERVRCG

Well-known member
OK, maybe I've missed something or it's been resolved already but I couldn't find it. For those who choose to take the 2% weight penalty what weight do we advertise on the car, the +2% weight right? In the case of my car I would be adding 31.5Lbs (which I don't have to add) but the new number would be 1575+31.5 = 1606.5 lbs.

I didn't see an area that addresses the rounding up/down question. If Sprite A shows up with 1606 and Sprite B shows up with 1607 who's right?

Not that 1 lbs is that big of a difference but there are always a few cars getting re-weighed.
 
Except for the Runoffs, I doubt any tech inspector will be willing to go through the process of an under weight car for 1 pound. Use the lower weight since 1245.5 is still 1245 and is until it reaches 1246.
 
ERVRCG":19ojiykd said:
O In the case of my car I would be adding 31.5Lbs (which I don't have to add) but the new number would be 1575+31.5 = 1606.5 lbs.

Not to argue with TWO noted rules guys but my take on the rule is from reviewing some weights (+ 2.5% or + 5% weight) on the spec lines. Precedence by Spec Line example would be the following. When obtaining the alternate weights printed when the increased alternate weight is less than .5 pound the alternate number is rounded down and when the alternate number weight is .5 pound or greater the alternate number is rounded up.

The alternate/new number would be 1575+31.5 = 1607 pounds.
 
Everywhere the GCR mentions rounding weights, it's to the "nearest pound". so 0.499 is rounded down. 0.500 is rounded up. just like we learned in elementary school maths. :)
 
Matt93SE":1pe4tvq3 said:
Everywhere the GCR mentions rounding weights, it's to the "nearest pound".
"Everywhere"? Not to sound argumentative but...show me where you see that. I've been referring everyone to Appendix G, which is the end-all, be-all for "FACTS, FORMULAS, AND MEASUREMENT STANDARDS".

There's only two places that would apply to the Production category: the GCR and the PCS. Maybe the PCS says differently? That would overrule the GCR.

GA
 
Greg Amy":1ab0ikfp said:
Matt93SE":1ab0ikfp said:
Everywhere the GCR mentions rounding weights, it's to the "nearest pound".
"Everywhere"? Not to sound argumentative but...show me where you see that. I've been referring everyone to Appendix G, which is the end-all, be-all for "FACTS, FORMULAS, AND MEASUREMENT STANDARDS".

There's only two places that would apply to the Production category: the GCR and the PCS. Maybe the PCS says differently? That would overrule the GCR.

GA
"Everywhere" is a whopping two places, both in the GT specs regarding rounding of % weight penalties for options. No, it's not in the PCS, but it provides context and should be interpreted and applied consistently throughout the GCR. (and if it's not, then it needs to be fixed because inconsistency there would be silly).

9.1.2.F.7.c.10.b & c and 9.1.2.F.7.e.10.
(holy crap the GCR needs to have the reference listed at the header of each page. I had to scroll through 10 pages to find all of the subsections to find all of the letters..)
Pages 321 and 322 of April 2021 GCR.

Appendix G.2.1 refers to the weight measurement standard, which is absolute minimum. i.e. if your car's spec weight was 2000lb, then a measurement of 1999.99lb would be illegal (although I get that scales at the race track aren't that precise and the tech will likely round that up and send you on your way with an attaboy for being too close to perfect.)


When calculating a weight to arrive at the car's race weight to put on the sticker, then you would round to the 'nearest pound'. Since there is no standard for calculations mentioned that I can find, you look for precedent set somewhere. This leads me to the GT specs referenced above where they're discussing weight adjustments by adding/subtracting a percentage of weight where it's possible to come up with a fraction of a pound. Other sections of the GCR mention "weight penalty", and specify a fixed amount of weight- 25, 50, 100lb, etc.

So the wording in the GT section is what I'd argue to set precedence since this method of calculation/ adjustment is relatively new and is not mentioned anywhere else.

Maybe this teeny tiny fraction of a pound we're arguing about should be mentioned in the PCS (and STCS) where they use % adjusters, similar to how it's mentioned in the GTCS?
 
Matt93SE":3angeher said:
No, it's not in the PCS, but it provides context and should be interpreted and applied consistently throughout the GCR.
I like your style, Pollyanna.

[Appeals Court]Thanks for your input.[/Appeals Court]

Round 'er up!

(and if it's not, then it needs to be fixed because inconsistency there would be silly).
Now yer talkin'. Consistency of regs (and philosophy) is key. You know the drill [write a letter...]
 
There's a part of me that now kind of wants to get rid of the varying weights on the spec lines of Limited Pre cars, due to what "level" of trans the car is competing with. The weight adders are all spelled out in the rules, so why does the spec line also have to illustrate that?

These now all apply as adders to a cars base weight in Prod:
- Add 2.5% for any gear ratios but stock engagement.
- Add 5% for any gear ratios and non-stock engagement.
- Add 2% for alt brakes.

My car for example has a base weight of 2235lbs, and I have a dog-box and alt brakes, so that's +7%. Do that math, and it's 2391.45 pounds. In my head, that rounds down to the nearest integer, because common mathematics practices, so 2391 pounds. However, looking at what Greg posted above from Appendix G and that weight is a "absolute minimum", is my absolute minimum 2391.45 pounds? Given that most scales won't read to the tenth of a pound, and will read either 2391 or 2392, will a reading of 2391 be illegal? Good question....and again, this is why our rulebook is a million pages long....

For context to Matt's point, I personally wouldn't go pointing to a rule in the GT section of the GCR as guidance of the thought process that should be applied to my Prod car. That's a long stretch that probably won't hold up in any protest or appeal.
 
kruck":1p8ou6j0 said:
The weight adders are all spelled out in the rules, so why does the spec line also have to illustrate that?
Concur. Let's recall I made that exact point but not a month or so ago, in regard to the "base weight" discussions on brakes. While I agree with Jessie on the intent of the regs, I disagree with his assertion that the regs are clear as written.

I'll again recommend (as you describe above) that all cars get a single base weight on the spec line, with an explicit note somewhere in the PCS that all percentage adders (trans, brakes) get applied to that specific base weight. It's maybe two extra sentences and removal of superfluous spec line info.

Given that most scales won't read to the tenth of a pound, and will read either 2391 or 2392, will a reading of 2391 be illegal?
Absolutely. Will it result in sanction? That's the question.

Given that scales can only read in whole numbers, and given that Appendix G was written long before there were category percentage adders that resulted in fractional weights, the PCS can override that question by explicitly stating it: weights are either rounded to the nearest whole number (up or down), or fractional weights must be rounded up as per follow Appendix G. Just call it out.

No one is going to win a championship because of 1/2 pound, but depending on enforcement they could certainly lose one. So let's clarify it.

...I personally wouldn't go pointing to a rule in the GT section of the GCR as guidance of the thought process that should be applied to my Prod car.
No, but his larger point is valid: the CRB should be ensuring consistency of application across categories.
 
TGA, That was the intent of my post above-- In order for tech to accurately enforce the rules and competitors to be able to follow the rules, concepts like this should be consistent between classes.

As for *right now*, if there's a procedure already spelled out in one class (GTCS) and nothing in another class, what would the tech shed and appeals board look to do? I would personally look for a precedent established elsewhere in the manual and be consistent with that, while I'm talking to the rule-writers to clarify it in this section. Using precedence is what the legal world does every day, no?
(Yeah, there's me and Polyanna again trying to oversimplify such a difficult concept as rounding numbers.)

This particular % adding concept where one can come up with fractions is mentioned in PCS, GTCS, and STCS, so I would assert that the "round to the nearest whole pound" concept should be mentioned in the general terms of the manual so you don't have to continually repeat it elsewhere. OR, it needs to be mentioned in every case there's a % factor. (ugh. call out the global variables at the beginning of the routine!)

Regarding 'absolute minimum' in Appendix G. That's intended for making measurements and establishing a yes/no line of legal or not. That portion isn't to specify rounding of a calculated parameter. So when you roll across the scales, absolute minimum, no maximum. If your car's spec line weight is 2000lbs, then 1999.999999lb is under and you're illegal; 2001- legal, 3000- legal. just don't be below 2000. How you come up with that 2000lb calculation is back to the class rules.

Just my $0.02 said in another fashion. this stuff *shouldn't* be freakin rocket science.
 
Matt93SE":2y6sv6p9 said:
As for *right now*, if there's a procedure already spelled out in one class (GTCS) and nothing in another class, what would the tech shed and appeals board look to do?
The problem is two-fold: what to put on the side of your car, and how to measure it. Since we can only weigh whole pounds I'll be safe and put the rounded-up number on my car. It's what I advise others to do.

I would personally look for a precedent established elsewhere in the manual and be consistent with that...
Well, sadly, you'd be wrong. Regs written in other categories do not apply to Prod, period end of story. It may well influence how a scru might choose to handle it, but the "controlling legal authority" is GCR first, PCS second, spec lines third. And none of those discuss it.

I would assert that the "round to the nearest whole pound" concept should be mentioned in the general terms of the manual so you don't have to continually repeat it elsewhere.
I agree. I suggest it's worth a letter for them to explicitly call it out in the GCR, especially since the number of categories with percentage adders is growing. If the CRB will not do that, then I suggest the PAC should do it in the PCS.

Regarding 'absolute minimum' in Appendix G. That's intended for making measurements and establishing a yes/no line of legal or not.
Sure. But even percentage-adder weight is binary, black and white. Our problem is that we can only measure to the whole pound. If you're supposed to weigh 2000.5 and the scales say "2000", then you do not meet the absolute minimum of 2000.5

Sure, our scales may display 2000 right up until 2000.5000, but we have no way of knowing that, so we go with what the screen says. It's either 2000 or 2001. Binary.

How would Tech/Appeals Court handle it? Dunno, likely depends on the situation. If you put 2000 on the side of your car you might get a pass, as long as no competitor tosses a protest on you for indicating a pound light or the scru cru decides to check your math.

But I suggest that you may want to round up just to be safe. After all, you won't notice the up-to-0.99 pounds anyway. - GA
 
ERVRCG":3m0x0a3a said:
OK, maybe I've missed something or it's been resolved already but I couldn't find it. For those who choose to take the 2% weight penalty what weight do we advertise on the car, the +2% weight right? In the case of my car I would be adding 31.5Lbs (which I don't have to add) but the new number would be 1575+31.5 = 1606.5 lbs.

I didn't see an area that addresses the rounding up/down question. If Sprite A shows up with 1606 and Sprite B shows up with 1607 who's right?

Not that 1 lbs is that big of a difference but there are always a few cars getting re-weighed.

Looking at the current spec lines it's clear that the transmission weights use the standard rounding rules... .5 goes up, .499 goes down.
 
Matt, the issue with trying to use any rule from another class/rule set is you then have to pick and choose which ones you want to follow and which ones you don't.

Trying to enforce a GT rule on a non GT competitor is a lost cause. I've won that battle more than once.

James R.
 
Effective 6/1/21:

In GCR, Section 9.1.5.C. add as follows:
5. For percentage-based weight penalties, all applicable percentage values shall be summed first, and then applied to the vehicle’s minimum specified base weight, as listed in the PCS. The minimum vehicle weight shall be rounded to the nearest pound. For example, a car with a 1950lbs minimum specified base weight, that’s running a non-stock gear-engagement transmission and non-stock brake rotors and/or calipers, would calculate its minimum weight as follows:

5% transmission penalty + 2% brakes penalty = 7% total penalty

7% total penalty * 1950 lbs base weight = 2086.5 lbs

2086.5 lbs rounded to nearest pound = 2087 lbs minimum weight


I presume the chart alternate weights will eventually be stricken?
 
Fixed. Base weight . Add the adder %s and add the total to the base weight . \
IE 5% plus 2.5% is 7.5% added to your base weight.
 
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