Slick vs. DOT usage

[ianacole]

I'm just trying to get a feel for tire preference. I know it's completely unscientific as not all GTS racers frequent these forums, but for those that do, please complete the poll in reference to your tire preference (DOT or slick). If you know of someone who has a preference and doesn't frequent the forums, please post their preference. Thanks.

[BStrom]

Depends on the competition present on the given weekend...

[DGrande]

I don't know enough to have an informed opinion. Because of that cost becomes a major factor. Are slicks more expensive than DOTs?

[pocracr]

Most GTS 3 and S2 Porsche cars are using DOT's. Mostly because they are crossing over from Porsche clubs which burden them with performance points for using slicks. Most also run on 17 inch wheels, which would mean new wheels to switch to slicks for some.

 

That being said, S4 and S5 Cars are all on slicks, except one on Kuomo. Yoko's for the most part and now some on Hoosier. Have not tried the Hoosier slick yet but looking forward to it, tho about 50.00 to 100.00 Peso's more each per tire compared to the Yokes.

 

I am pretty sure that the S4, S5 and GTSU cars will for the most part all run slicks.

 

Sergio Nardi

SoCal GTS Director

[RSCoupe]

Budget permitting, I would run the new Hoosier slicks. Otherwise R6's...

[B.Watts]

Slicks because that is what our car is setup for in order to be competitive in our BMW CCA class. Ultimately, I think the rules are unfair towards slicks and that R-comps are a better choice for being competitive if we detune our motor and run GTS4 where we can place our car right at the top of the power/weight ratio for the tires we chose to run. But, it's too much work to dial the car in for different tires between weekends with different clubs, so we'll likely end up on slicks regardless. If we don't detune the motor and run GTS5, we might as well run slicks because we're nowhere near the top of the power/weight ratio anyway, so every little benefit helps.

[Keith Andrews]

I'm not really sure what I'm voting for here. I use DOT's because that is where my car fits best class wise with the current rules. If your are asking would I prefer to race on slicks that's a different deal. Slicks would be great as long as the current classification rules are thrown out. My car would be uncompetitive otherwise. Down at the GTS 1/2 it seems like you take a much greater hit to run them, my math could be wrong. My .02

[Jim Peterson]

I prefer to stay with DOT so I can crossover to SCCA Improved Touring without making tire changes. I may start each weekend with new tires but I really don't want two separate piles of tires, ensuring backups for each type, and modifying suspension settings for each one. Plus DOTs are lower cost.

 

Jim Peterson

#92 GTS2

[Bull993tt]

I would love to run slicks, but it would bump me to GTS5 and I would be at the bottom of the food chain in 5. So as a result, I run Hoosier R6's.

[cstreit911]

I didn't get a chance to vote, but I also run slicks. WHy? Because at my car's power to weight I can. I'm currently running Dunlops GT's but only because they were the best option for my wheel size and diameter. I am anxious to try out the new Hoosier slicks and will post a comparo once I get a chance.

[JSG1901]

I think Hoosier ought to give somebody a set of DOTs and a set of comparable slicks (pick me! pick me!) and let us run them back to back to see what kind of a difference they actually make. This, for purely scientific reasons, of course.

[B.Watts]

I think Hoosier ought to give somebody a set of DOTs and a set of comparable slicks (pick me! pick me!) and let us run them back to back to see what kind of a difference they actually make. This, for purely scientific reasons, of course.

 

Win enough races and they'll give you all the tires you want.

[JSG1901]

Win enough races and they'll give you all the tires you want.

Um...actually, that hasn't been a problem. But, since I'm winning on the DOTs and would have to ballast up quite a bit to get to the right weight for slicks, it would be kinda silly to waste my contingency tires seeing what happens.

 

I think it would be a really interesting experiment for GTS and Hoosier to take a car like mine (or yours, or somebody's) that we know is consistently fast, that has a driver consistent enough to do similar-enough laps to get meaningful information, and that can make it down to the DOT minimum weight (and ballast up to the minimum weight for slicks), and run that car full bore on both DOT and race tires at the correct class minimum weight for each and see how they stack up in terms of lap time.

 

I just don't want to use my stack of won-but-not-used-yet tires to do it. I can use them to win MORE tires, which is highly favorable in terms of my racing budget. Seems like something the fellas from Hoosier ought to be interested in (to me, at least) because it might generate some new sales in, well, whichever wins.

[B.Watts]

I would rather see the process used to actually adjust the weight difference between slicks and R-comps currently allowed in the rules. As far as I know, no "science" was used to set the weight differences between R-comps and slicks when the rules were created. For that matter, I'm not sure why we even differentiate...EVERYTHING else in this class is wide open rules wise, but we make an arbitrary distinction between type of tires used? That just doesn't make sense to me...especially since it doesn't seem that any real testing went into determining the penalty for running slicks. Seems a little bit outside of the "spirit of the class", to pull a term from a few other threads lately.

[JSG1901]

I agree with you that there was probably no science involved in the process when the numbers were set but, honestly, I don't know that to be true. Considering that there is almost certainly some kind of difference in performance between full-race and DOT tires, though, I would say it is completely within the spirit of the rules that there would be a different target power-to-weight ratio for each.

 

Regardless, it would be interesting to know how right or wrong the respective ratios are. I'm not sure if we could tell that from the analysis of one class, but maybe....

[B.Watts]

I agree with you that there was probably no science involved in the process when the numbers were set but, honestly, I don't know that to be true. Considering that there is almost certainly some kind of difference in performance between full-race and DOT tires, though, I would say it is completely within the spirit of the rules that there would be a different target power-to-weight ratio for each.

 

I know it to be true, because I know the effort it would take in order to come up with some usable numbers.

 

There is inherently some kind of difference in performance between a GTS3 car on $50K Ohlins through-rod dampers with a full carbon underbody with tunnels, diffusers, etc and a bone stock, off the showroom floor GTS3 car with a cage and some safety items added, but I don't see anything in the rules to "equalize" those. Why are tires the ONLY modification to a car that we attempt to equalize in the rules. Even worse, why is that ONLY modification just some arbitrary number...it's something that couldn't actually be determined without EXTENSIVE testing in at least 10 or more various cars.

 

There are inherently some performance differences between a 944 and a BMW E36. Would you support an arbitrary penalty of 200 pounds for running a 944 rather than a BMW? Heck, since you won the 2008 championship, we even have some "science" to say that the 944 has an unfair advantage over the BMW's in GTS2.

[Michael G.]

I fully agree with Bryan - the ratios for slicks vs. DOTs seems to be set arbitrary, with no real technical data behind the theory. My understanding, that in the early days, trying to attract more drivers to participate, founders of the series felt that simpler rules would help. And it did. Only now, we begin to face legitimate questions of reasons behind certain rules more and more often, with more cars on the grid and more competition. I am not even sure how much of a true science behind the basic ratios set for classes as well. Following the spirit of the open rules, one could argue that tires should be as free as other components (definitely, if suspensions, drivetrains, transmissions and aero/body are free), as long as the weight/hp is respected. I also think we tend to generalize DOT's and slicks, even though, we know those are often not all the same. There is a great deal of improvement and development on the DOT side of it, where the latest models are not too far or equal to some models of slicks. There is also a great variety in between slicks in terms of performance. Few years ago, here in the NE, we were working on the new set of rules for the autocross program, when approached few technical engineers from the leading tire manufacturers to get their feedback on the issue of DOTs vs. slicks. The general response was, that because of the more and more stringent requirements applied to the DOT tires, there is more development and improvement seen in that sector, resulting in closing the gap with slicks. It is not uncommon to see someone to run qualifying session on Hoosier A6s, taking advantage of the softer compound, switching to R6s for the race. For a few hot laps A6s may be as good as slicks. If we will decide to address those issues (and I hope we will) in the off season, we may need to look into more than tires, as Bryan noticed. Hopefully, we can create simple and fair system, without damaging the spirit of the series. Respectfully, Michael Gershanok - NE GTS Director.

[JSG1901]

Interesting thread.

[Cory M]

I'm not a GTS participant yet so I didn't vote on the poll. We have a couple of 911's and are planning on doing some GTS events in the future so I've been researching the class and checking out the forum.

 

My view from the outside on the slicks vs DOT discussion and the idea of having open tire rules: We all know slicks are faster. So without some sort of handicap, in the long term all drivers will be required to run slicks to be competitive. Slicks are more expensive than DOTs so everyone's cost to race will increase. Bryan's "thru-rod damper, carbon underbody, etc" example isn't really valid because those modifications are a one time cost some people may choose to do, while tires are a consumable that everyone HAS to buy in order to race.

 

Having the different tire rules actually provides MORE options for selecting your class. I've been looking at race results and the class calculator to decide what weights we can realistically run at and what tires we would be more competitive on. If I can't get the car down to the right weight or don't want to spend a lot of money on composite bodywork to lighten it up I can choose to run a faster slick tire and regain some of that advantage, without the tire rule I wouldn't have that option.

 

Since 75% of the people who responded to this poll are on DOTs, and DOTs are cheaper than slicks, it would probably make more sense to mandate DOT tires than it would to change the rules so everyone needs to run slicks to be competitive (I'm not advocating that, just a counterpoint).

 

I don't know the history of the tire rule or how fair it is in practice. An independent scientific analysis of the handicaps would be ideal but would cost a lot of money and take time, and people would still argue about the results. It would be easier to analyze race results and trend tire usage, but with so many differences in cars and drivers it probably wouldn't provide many good conclusions.

 

Anyway, I think it make sense to have different ratios for slicks and DOTs.

[B.Watts]

We all know slicks are faster. So without some sort of handicap, in the long term all drivers will be required to run slicks to be competitive. Slicks are more expensive than DOTs so everyone's cost to race will increase.

 

Do we know that? Has anyone run any testing to prove it? What if I'm running some slow slicks (Yokos maybe) and you're running some fast R-comps (Hoosier A6's) and your R-comps are actually faster than my slicks? Besides, Yoko slicks cost within $20-30 of Hoosier R-comps. Your cost argument is bunk...Hoosiers are faster than Toyos. Hoosiers cost more than Toyo's. Both are legal in the R-comp category. Does that mean that it's unfair for people to run Hoosiers if some folks are running Toyos? What happens when Hoosier releases a special R-comp that costs more than slicks and only last 2 heat cycles. Will it be "unfair" to everyone else that's running the slower Hoosiers because the cost to "compete" went up...that's an important distiction. It doesn't increase the cost to RACE, as you put it. Just the cost to COMPETE. Regardless, the fastest R-comps are already the most expensive (Hoosier or Hankook) and the fastest slicks are the most expensive (Dunlop, Michelin, and Hoosier), so unless we go a spec tire, there is already an increased cost to compete no matter which tire "class" you choose to run.

 

Bryan's "thru-rod damper, carbon underbody, etc" example isn't really valid because those modifications are a one time cost some people may choose to do, while tires are a consumable that everyone HAS to buy in order to race.

 

What if my really trick dampers need to be rebuilt 3 times a season and revalved for every track I go to? And my carbon underbody has to be repaired because it scrapes the ground over the curbs. Everyone HAS to buy brake pads...does that mean that it's unfair to the guy running PepBoy pads that I choose to run a much more expensive race pad? Of course not...this is an open rules class.

 

Since 75% of the people who responded to this poll are on DOTs, and DOTs are cheaper than slicks, it would probably make more sense to mandate DOT tires than it would to change the rules so everyone needs to run slicks to be competitive (I'm not advocating that, just a counterpoint).

 

Sounds far more fair, but not really within the spirit of an "open rules" class. It would be somewhat lame to say I must run a street legal tire on a car that can legally have diffusers and tunnels, $50K dampers, a suction fan, multiple turbos, nitrous, etc.

 

Besides, most people are running non, single, or double adjustable shocks. Should we change the rules to outlaw or penalize triples and quads? Most people are running N/A motors. Should we outlaw or penalize turbos? Most cars are running stock engine management systems. Should we outlaw or penalize Motecs? Is this, or is this not, a simplistic open rules class? It just seems strange to me that tires are the ONLY modification penalty rule that we have in the entire rulebook.

 

By the way. We've had Dunlop Slicks, Yoko Slicks, Pirelli Slicks, Hoosier Slicks, Hoosier R6's, and Hoosier A6's on our car. While we never got around to optimizing the setup for the A6's or R6's, I can say pretty confidently that the gap between top of line R-comps and slicks is not nearly as much as most may think. Depending on specific cars and specific moments of the race, one may be better than the other.

 

This is a racing class where you can start your build with a $500,000 Porsche GT1 or a $10,000 1995 BMW M3 and then spend $500,000 (or more) in build cost on each while still being within the rules. The argument that creating different class structures for slicks and R-comps helps control the costs to compete just doesn't hold much water with me. If you tell Racer A that he can only buy R-comps, any money he saves from not buying his slicks will simply be poured into making his car even faster in other ways...and he'll still be beating you, so he'll still be winning the free tires that allow him to run stickers for each race anyway.

[maxxfish]

I'm going with Bryan on this one. I agree with him that the high-end R-comps are getting to be just as fast as some of the slicks out there...for sprint races at least. If we were running 60-minute races, things might be different.

 

I'm running slicks for 3 reasons:

 

There are only 2 cars including myself running in GTS-4 in the Mid Atlantic, so I can't win tires

 

I can buy (since I can't win ) used slicks for $75 each

 

I'd need to lose 250 pounds to be near the threshhold of GTS-4, so I might as well run slicks.

 

If the GTS-4 class doesn't grow in the Mid Atlantic, maybe I'll just add 600 pounds of ballast, get some R-comps, and run GTS-3!!! Now THAT'S a can of worms....

[Eric W.]

 

 

If the GTS-4 class doesn't grow in the Mid Atlantic, maybe I'll just add 600 pounds of ballast, get some R-comps, and run GTS-3!!! Now THAT'S a can of worms....

 

O DAYUM! BRING IT!

[JSG1901]

If the GTS-4 class doesn't grow in the Mid Atlantic, maybe I'll just add 600 pounds of ballast, get some R-comps, and run GTS-3!!! . Now THAT'S a can of worms....

Go for it...at least you'll have somebody to run with!

[B.Watts]

If the GTS-4 class doesn't grow in the Mid Atlantic, maybe I'll just add 600 pounds of ballast, get some R-comps, and run GTS-3!!! Now THAT'S a can of worms....

 

maxx - We've got a GTS4 tune now that caps the curve. We are probably going to choose which class to run on a given weekend based on competition and the ability to win tires. For instance: it makes no sense to run GTS5 if only 1 other car is running or if the 600+ hp Porsches show up, because we won't have a shot at winning tires. If there are 2 consistent GTS4 cars, we might be able to help build numbers at some events.

[ELEPHANT1]

Now this is an interesting thread. My initial thinking was that age old "slicks are faster than DOTs" but I am well aware that gap is not as big as it used to be. And honestly, I could not come up with one valid argument for having classes split based on tires as a single component choice. Though I think it would be detrimental to me personally, I think I'd rather see tires not be a defining factor of classing. Very interesting.

 

Cheers.