Non-DOT Slicks

[eastcoastbumps]

DOT tires must have all DOT required labels marked on the sidewall. This includes size, load rating, date & location of manufacture, UTQG rating, speed rating, number of plies, max pressure etc. and they require 2/32" wear bars and tread that is over 2/32" deep. They're tested to see if they meet the load and speed rating the manufacturer puts on the tire. I'm not sure what else it takes to get DOT approval, but if a tire fails a 130mph test, they can put a 120mph stamp on it and still pass DOT. The Hoosier A6, as seen here with its two 3/32" groves, barely complies to DOT standards.



As an added note on safety, it may not be a good idea to buy non-DOT Hangzhou Zhongce Rubber Co. race tires made in China, even though they may have the same specs as Michelin Blues.

[naschmitz]

no thats why you keep it as a dot rule . if you do away with the dot tire rule it will end up costing car owners more money buying the fastest up to date tire . a set of new slicks cost more than a new set of dot tires . so with people now going out and getting a new set of slicks it will cost less in what way ????? a full hoosier slick for my diasio cost twice the money than the R6 i buy for the porsche in the same size . so why would you want to throw out the dot rule ?????

It depends on what you consider the reasoning behind requiring DOT tires in SP and the other ST and SS classes to begin with. If the rule is intended to stop people from buying fast race tires every event then it fails miserably as a rule. You can still go out and buy a new set of fast race tires that are DOT approved for every event and have an advantage over your competitors that don't.

If the rule is intended to keep street cars competing on a street tire, then it still fails as rule, since DOT race tires will not pass any state safety inspection (at least not where I live!) and are not approved for street use. In some competitors eyes the rule is not serving either function, so the rule is useless.

With that understanding, the rule should be either changed or eliminated. Make SS, ST and SP a true street tire class and require tires that are street legal with more than 2/32" of tread. Disallow any tire branded 'Competition Use Only' by its manufacturer or require tires to have a certain UTQG rating. Or go the other way and eliminate the DOT requirement in SS, ST, and SP, since you can purchase a proper race tire that has no business being on the street with a DOT stamp already. The sole purpose of the DOT stamp on race tires is to skirt a street tire rule.

That's essentially the same argument I proposed in a rules change, but the board rejected it without further action.

[brucesallen]

No one has mentioned one difference between DOT tires and wheels and race (read slicks). Because of the construction requirements, DOT is four times heavier than race. In my case, a Hoosier R6 ( DOT) on an RX7 stock wheel weighs 45 lbs on my Lotary 7 street rod. A Hoosier slick on a track-only wheel on my Formula E race car is 12 lbs. Big difference. 120 lbs extra on an 1,800 pound car.

[eastcoastbumps]

No one has mentioned one difference between DOT tires and wheels and race (read slicks). Because of the construction requirements, DOT is four times heavier than race. In my case, a Hoosier R6 ( DOT) on an RX7 stock wheel weighs 45 lbs on my Lotary 7 street rod. A Hoosier slick on a track-only wheel on my Formula E race car is 12 lbs. Big difference. 120 lbs extra on an 1,800 pound car.

Bruce, I think you need to get a better scale, or other apples and oranges. Either way, when has the weight of a component ever been the issue in SP? You can go as light as you want with nearly any part of the car and there are no minimum weights for cars in any of the classes.

[brucesallen]

No one has mentioned one difference between DOT tires and wheels and race (read slicks). Because of the construction requirements, DOT is four times heavier than race. In my case, a Hoosier R6 ( DOT) on an RX7 stock wheel weighs 45 lbs on my Lotary 7 street rod. A Hoosier slick on a track-only wheel on my Formula E race car is 12 lbs. Big difference. 120 lbs extra on an 1,800 pound car.

Bruce, I think you need to get a better scale, or other apples and oranges. Either way, when has the weight of a component ever been the issue in SP? You can go as light as you want with nearly any part of the car and there are no minimum weights for cars in any of the classes.

It is simple. SP requires heavier tires. Those steel belts are heavy.

[savage217]

I'm pretty sure the scrubs and many slicks are able to handle the "weight" of a street car. The Conti scrubs are run on ST 330's and M3's that can generate higher speeds and forces than my 3000lb SPB street car. Also i'm sure most would agree that DOT street tires are an extremely broad subject. If we are worried about a safety issue with slicks on street cars than we should be prohibiting any street car with unsuitable tires on the track. I am referring to cheap Chinese made all seasons which you can find on a lot of novice cars that most likely weigh a heck of a lot more than 3000lbs. Just saying....