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JSG1901

DISCUSSION CLOSED: Make non-DOT tires a flat adjustment

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JSG1901

Type

Modification to an existing rule

 

Existing rule section (if applicable)

Non-DOT Tire

 

Proposed change

Make Non-DOT tire a flat .5 modification adjustment. Currently adjustment factor varies widely from class to class.

 

Reason

Standardize "spread" for Non-DOT tire.

More aligned with Super Touring rules for easier crossover.

 

Proposed new wording

None provided.

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KTL

No

 

Seems like messing with an already well-functioning formula. The existing formula was clearly developed with some understanding that as the wt/pwr ratio declines, the benefit of the non-DOT tires is not as prevalent?

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Luke P.

Against

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UKRBMW

Also against

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mikew968

The current system does not work for most of the classes. 1, 2, and 3 get too mcuh of a penalty to run slicks.

 

I would be for this rule as it seems more balanced.

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911.racer

I agree with Mike. There is too much of a spread in the lower classes. No one is actually running slicks (that I know of).

 

These days the DOT's are very close to the performance of the slicks. This was not the case 5 years ago. I run slicks in GTS4 now mostly becuase the sizes are better, but in GTS1 I would never have considered it.

 

Thanks

 

Ed

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jvanhouten

Against, but I agree that maybe the GTS/1 and 2 (maybe 3) assessments need to be re-evaluated.

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JSG1901

For the record, the current difference between DOT and non-DOT tires in each of the classes require the following amount of additional weight for non-DOT tires

 

GTS1: 8.11%

GTS2: 10.34%

GTS3: 9.09%

GTS4: 5.88%

GTS5: 9.09%

 

So, other than GTS4 which has half the handicap of the others, the ratio is pretty close to the same for each class as it is today.

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ILIKETODRIVE
For the record, the current difference between DOT and non-DOT tires in each of the classes require the following amount of additional weight for non-DOT tires

 

GTS1: 8.11%

GTS2: 10.34%

GTS3: 9.09%

GTS4: 5.88%

GTS5: 9.09%

 

So, other than GTS4 which has half the handicap of the others, the ratio is pretty close to the same for each class as it is today.

Reading the rule proposal and seeing the spread in numbers, it makes sense. Drop the high (GTS2) and low (GTS4) and average the other 3 (8.76%) across all classes.

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Brad Waite

I vote no.

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cstreit911

As soon as you muck with the power to weight ratios you introduce potentially very expensive changes to the classes you impact for all drivers involved.

 

Taking GTS4 because I know it well. If you change it to 1.0 and make these cars run 9.5:1 for slicks... That's an average of 160-170# of ballast that now must be added to the cars running slicks requiring major changes to suspension alignments, spring rates, etc... which get very expensive. By that same token now the GTS2 cars running slicks all go back for engine mods to get more horsepower.

 

What will happen is that all the GTS4 cars will switch to DOT's because the penalty is now too big (You see there isn't a huge disparity in the slick vs. DOT cars in GTS4) and have to change their tunes, suspension, tire setup, etc... And the GTS2 DOT guys will all freak out because the guys moving to slicks now have a huge advantage.

 

There is no problem with the ratios as they stand now. No class has a huge disparity in times with the slicks vs. DOT. So why change it?

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doclouns

Seems silly as is, make it consistant.

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philstireservice

Just to add more info - slicks (not GA Tires) are 2 seconds faster per lap than a DOT on average. They do cost more and do have a shorter fast life.

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cstreit911

That also depends on the car. It was two seconds on my lightweignt car. Less than a second on the heavier version.

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autodoctor911
For the record, the current difference between DOT and non-DOT tires in each of the classes require the following amount of additional weight for non-DOT tires

 

GTS1: 8.11%

GTS2: 10.34%

GTS3: 9.09%

GTS4: 5.88%

GTS5: 9.09%

 

So, other than GTS4 which has half the handicap of the others, the ratio is pretty close to the same for each class as it is today.

 

 

I am a little bit unclear on what the proposed flat rate penalty would do to affect the situation.

 

Right now GTS 1 and 2 have a 1.5, GTS 3 a 1.0, GTS 4 a 0.5 and GTS 5 a 0.6

 

if it were a flat 0.5, this would be reducing minimum weight for slicks in all classes except GTS4, correct?

 

I assume the current digressive(except for the 0.1 increase from GTS4 to 5) weight penalty is due to the fact that as the cars get more power to weight the slicks have less of an advantage?

 

I would think a more powerful car would benefit more from slicks than a less powerful one, but that is just theory, and this should be figured out by actual results.

 

I take it, that right now it is prohibitive to run non-DOT tires in most of the lower classes, and this change would make it more feasible. Slicks may cost more in general, but some cars may be limited to slicks due to size availability, or other reasons. Also, certain sizes, like 15" slicks can be had for significantly less than a Hoosier A6/R6 in a similar size.

 

I would think that it would be good to keep each class a different ratio, but adjust each one based on what is currently working. If slicks are slower right now, due to an unfair weight penalty in a certain group, change that class's adjusted HPtoWeight. Maybe a increase in the weight of the DOT tire cars would be easier to implement, since it is almost always easier to add weight than remove it or increase HP, if a car doesn't have much ballast.

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scottbm3

Leave rule as it is currently

 

 

 

 

 

-Scott B.

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llis

Are there actual metrics that this proposed rule change is based upon? Or is 0.5 an arbitrary number?

 

As written, I'm against. However, unless metrics suggest that life is different in GTS4, I would be in favor of making the factor the same across all classes.

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