Question/Rationale for Brake Modification Points

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Tom Weber
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Question/Rationale for Brake Modification Points

Post by Tom Weber » Wed Sep 07, 2005 1:34 pm

Why do modifications to the braking system have such a high penalty relative to other mods?

My view:
On late model 911's (1989 and later) modifications to the caliper or rotors do not have any significant impact on braking capacity (distance) but mainly affect the cooling of the system. I believe this is true for mods like addition of "big reds" to 964 and 993 models or taking the PCCBs off GT2 and other cars (in favor of an equivalent steel system). Brake PADS have a bigger effect than caliper size, especially in a 3 lap time trial.

So, given that time trials are so short, why should the mods we do to aid cooling in DEs or racing carry such a heavy penalty? 10 points for calipers and 5 points for ducts and 20 points for rotor sizes and 5 points for a master cylinder means 40 points for parts that do not make the car go faster (and one could argue that the additional unsprung weight would have a negative effect). Heaven forbid I'd alter the bias. This is almost an entire TT car class for a simple modification that shouldn't affect lap time but is made for component longevity and endurance.

Is the difference more pronounced in other models or earlier cars?

What was the rationale for the assignment of the points as they stand today?

If you want references to the fact that bigger calipers or rotors don't stop a 964 or 993 any faster, I'll be happy to provide them.
Tom Weber
964 GTL/GT3 (Tom's Turtle, #54)

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Dan Thompson
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Post by Dan Thompson » Wed Sep 07, 2005 9:00 pm

Good points Tom,
I wish more folks would take the time to read the points proposal in a complete manner to see how they effect their car. Not just one mod. :o
Dan Thompson
GGR DE/TT/CR Racecontrol

dtfastbear
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Post by dtfastbear » Thu Sep 08, 2005 12:45 pm

Tom and I discussed this offline, but I thought I should respond in the forum since others might have the same question.

One decision that we had to make along the way of developing the system was if we wanted to assign points for modifications differently based on the model of the car that was being modified. For instance, early 911's with modified engines that DO benefit significantly from larger brakes, even in 3 laps, would perhaps receive 40 points for brake upgrades while Tom's car or a 996 might receive minimal points for a brake upgrade, as the marginal improvement is smaller. We decided, after much debate, not to do that. While it would make the system more accurate, it would also make it more complicated to the point that it would be logistically impossible to maintain, understand and administer. We feel like we've struck a good balance between having enough detail in the points assignments to keep the classes fair and the practical requirements of having a system that a casual, volunteer club can administer.

If anyone feels the specific point assignment for braking components don't meet this criteria, I encourage you to propose a change to lower the points for calipers or rotors specifically to try to bring the total points for a brake upgrade down - that'll give other competitors a chance to weigh in on how significant of a performance gain a brake upgrade is.

For the record, since Tom raised the issue, I'd like to point out how the current system treats brakes differently. Once you get to Production, you are allowed to forward/backdate any 911 brakes for any others. As Tom mentions, for cars like his one might only want to do this for component longevity. Ducting (from the front bumper, not an under car scoop) would accomplish this just as well (for a lot less money), but that would put you into Street Modified. Also, if one wanted to go a cheaper route and use 944 or Boxster brakes on his pre-89 911 (a very common modification) he'd also find himself in Street Modified. Running proper ducts is only 5 points in the points proposal, acknowledging that cooling in and of itself doesn't necessarily play a huge role in a 3 lap time trial. We didn't want to punish real brake cooling the way the current system does.

Cheers,

Dean
Faster than the average bear...

dtfastbear
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Post by dtfastbear » Thu Sep 08, 2005 12:53 pm

Dan,

I, too, wish all those who care enough to weigh in on the proposal would take the time to fully understand it as Tom has.

Modifications to entire systems are broken down into their components very purposefully, and brakes are a great example of why the points system provides much more flexibility and fairness than the current system. If you just want to upgrade calipers (and perhaps the MC to accomodate that) you are charged much fewer points than if you do a full upgrade including upgraded rotors, adjustable bias, etc. Go ahead and put those Boxster calipers on your 89 Carrera with the standard discs. That'll just get you a few points for the modest performance gain instead of a one way ticket to Street Modified like in the current system.

In other words, the points system, by design, acknowledges that upgrades aren't always down as a complete system. When they are, they should accumulate appropriate points, but when individual components are upgraded, one shouldn't instantly find himself uncompetitive in Street Modified, as in the current system.

Dean
Faster than the average bear...

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Tom Weber
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Post by Tom Weber » Fri Sep 09, 2005 10:29 am

I'd like to thank Dean for his replies to my questions and publicly provide my support to the points system. While I do not believe the points system is perfect (nor do I believe it ever will be or could be), I do believe it's a strong move in the right direction (fewer classes and a more rational basis for the classification).

I think the brakes were a good example to me of why "tweeks" to the points assigned might be needed. I'll be happy to make a proposal next year for some revisions to brakes and other systems (assuming we get it accepted this year).

I do spend time comparing cars and drivers to the points. I gave Dean my fedback regarding my car being in the same class as a nearly stock GT3 (what a joke!) or even a nearly stock 993 tt (also not what I'd consider a fair comparison). What I'd like to do is try and determine why the various cars get classed where they do and suggest adjustements to the points to get them properly classed (because I, of course, know what cars should be in what classes :wink: ).

One other thing to consider - what's with the idea that everything must be divisible by 5 points? Replacing the battery (which might save you 25 lbs) is 5 points and moving it another 5? Yet completely gutting the interior to save a few hundred pounds is 10 points? Or better yet, I can remove my cat for a cat bypass (that in my car gives about 15 hp by my dyno tests) and only get a 5 point penalty - a lot more bang for the point than a battery change! Will the group consider assigning 1-2 points for trivial modifications instead of everything by 5?
Tom Weber
964 GTL/GT3 (Tom's Turtle, #54)

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