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ianacole

Slick vs. DOT usage

What tire do you run?  

60 members have voted

  1. 1. What tire do you run?

    • Slick
      16
    • D.O.T.
      44


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kbrew8991

don't slicks require (sometimes) drastic changes in setup to get the most out of them?

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philstireservice
don't slicks require (sometimes) drastic changes in setup to get the most out of them?

 

 

Radial slicks don't require drastic changes at all......bias ply require a lot less negative camber and some other tweeks here and there.

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cstreit911
so if the slick rule may be changing what about the tube frame rule?

 

What cars came from a manufacturer already a tube frame? None that I know of, so I would vote no to changing that rule.

 

What cars come from the factory with 4 way adjustable $50K dampers, 10,000 RPM motors, and full race aero? All of those things are perfectly legal in the rules.

 

That said, I agree with you. In my opinion, we should get rid of full tube frames completely, requiring the passenger compartment portion of the chassis to at least remain, which would allow for "tube framing" in front of and behind the passenger compartment if desired. Just seems more in the spirit of the class to at least keep the main portion of the chassis.

 

I'm with you guys on this. IMO a tube frame car is a one-off. It's a shadow of the original car. It's "Billy-Bob's chassis shop" manufacturered with BMW or Porsche (or whatever) bodywork hung off it.

 

Let me ask you this: If a car is a tube frame.. ...and it has a Porsche front clip and a BMW rear-end. Which engine is it allowed to have?

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cstreit911

Comparative thoughts on this: (tongue in cheek)

 

I say we vote that the slick penalty is too much, because the difference between my Hoosier A6's and the Avon slick is only 3/10ths. It's not fair.

 

I say we vote that the slick penalty is too little, because the difference between my Kumho V710's and the Dunlop GT slick is 3 seconds. It's not fair.

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kbrew8991

should be based on the most, if you're not taking full advantage of an allowance in the rules you cannot complain about being uncompetitive....

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cstreit911

...but what is the most? Who decides that?

 

The whole basis of the discussion is coming up with a formulaic way of setting the penalty. There IS no formulaic way because you'd have to base it on objective results.

 

...and lets say for argument we did come up with a formula for how many seconds quicker slicks are, you'd still THEN have to come up with a formula on how much weight this equals to set the power to weight ratio... ...and that is different for every car and every class. So to reduce x seconds per lap on a BMW M3 might be different than that of a 325, a light 911, and a factory 911. So there is no way to calculate the weight.

 

Which brings me back to the point you made ("if you're not taking full advantage of an allowance in the rules you cannot complain about being uncompetitive....") , and one that most of us wholeheartedly agree with. The rules on that work, and have worked. If slicks works better for you with the current rules, use them. If they don't, then don't use them.

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B.Watts

Some data from the VIR Summer Slam weekend earlier this summer. We ran our car "detuned" to GTS4 power levels in order to run GTS4 and Time Trials. We ran R6's in GTS4 and A6's in the Time Trials. We also went out in practice and warm up sessions on R100's to get some data points. Here were the results...same car, same weekend, same track config:

 

Best R100 lap, 2:03.592

Best A6 lap, 2:03.830

Best R6 lap, 2:04.292

 

Keep in mind, this is on a setup "optimized" for slicks, as that's all we have run for the last 6 years or so.

 

All sessions had quite a bit of traffic all weekend. Depending on how traffic went, any of the tires could have "won" the fast lap for the weekend. 2-3 seconds per lap between R100's and A6's, and 4-6 seconds per lap between R100's and R6's just don't exist.

 

As I mentioned in this thread earlier, I know of at least 1 IPrepared BMW (crosses over to GTS3 with a little weight) that runs 2:04's at VIR. The idea that he could slap on some R100's and run 6 seconds faster, 1:58's, is just plain silly.

Edited by Guest

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kbrew8991

is the R100 the fastest slick out there?

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B.Watts
is the R100 the fastest slick out there?

 

Hard to say. I've run Dunlops, Pirellis, Yokos and Hoosiers.

 

In order of speed, I would place them this way:

 

1) Dunlops

1) Hoosiers

3) Pirellis

4) Yokos

 

To determine which is fastest between Dunlops and Hoosiers, I would need to run them back to back on the same day which I haven't done. The Hoosiers were designed to compete for Porsche owner dollars against the Michelin Blues, which are supposed to be some of the fastest slicks out there. We've never run Michelins due to sizing, availability, and price.

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jrgordonsenior

Best R100 lap, 2:03.592

Best A6 lap, 2:03.830

Best R6 lap, 2:04.292

 

Have you tried the R80's?....

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cstreit911
As I mentioned in this thread earlier, I know of at least 1 IPrepared BMW (crosses over to GTS3 with a little weight) that runs 2:04's at VIR. The idea that he could slap on some R100's and run 6 seconds faster, 1:58's, is just plain silly.

 

However if anyone believes that you CAN, I also have a bridge you might be interested in purchasing.

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B.Watts

Best R100 lap, 2:03.592

Best A6 lap, 2:03.830

Best R6 lap, 2:04.292

 

Have you tried the R80's?....

 

Yes. Tried those at Road Atlanta BMW CCA Oktoberfest about a month ago. Tried both R80's all around as well as R80's on the front with R100's on the rear. Very little difference in ultimate grip from what I could tell (my father and I were sharing the car that weekend, so it's hard to establish a baseline), but there are some differences in the slip angles they like and the way that they come up to temperature.

 

All of this said, I still love the Hoosier slicks. They are fast, cheaper than Dunlops, and (at least in 2009) available for free with the NASA contingency. If the contingency keeps going, we'll continue running them in 2010 for sure.

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