DOT "slicks" vs real slicks

[Captain Snooze]

This is just a curiosity question; I am not considering putting slick slicks on my car (although I do use DOT slicks).

What difference is there in construction, grip, performance, compromise between a DOT slick such as Hankook Z214, Kumho V710 and a proper racing slick?

Now that I mention it what does the DOT actually mean considering DOT slicks aren't for road use?

[Icecreamtruk]

Very very interested in this topic, thanks for asking. I have only used semi-slicks myself, but the fastest guy in out time attack series has a wild variety of tires, and the difference between Hoosiers R6 et Pirelli Slicks (dont know which compound) is about 1sec in a 50sec tight course. Car is an WRX STI, stripped, caged, basic aero and around 320whp.

[Lynxis]

Originally Posted by Captain Snooze

This is just a curiosity question; I am not considering putting slick slicks on my car (although I do use DOT slicks).

What difference is there in construction, grip, performance, compromise between a DOT slick such as Hankook Z214, Kumho V710 and a proper racing slick?

Now that I mention it what does the DOT actually mean considering DOT slicks aren't for road use?

DOT slicks are, technically, legal to drive on the street. Not that you'd want to because the compound isn't designed for it though, they won't get warm enough for decent grip and they'll wear too quickly.

As for the differences between the DOT slicks and real slicks, I don't know but I understand that DOT slicks are considered the last step before going to a full slick.

[lutfy]

Originally Posted by Lynxis

DOT slicks are, technically, legal to drive on the street. Not that you'd want to because the compound isn't designed for it though, they won't get warm enough for decent grip and they'll wear too quickly.

As for the differences between the DOT slicks and real slicks, I don't know but I understand that DOT slicks are considered the last step before going to a full slick.

The DOT slicks are essentially just lined up (in the middle) just to pass the DOT or street requirement as most racing sanctions require. This should not be considered a lack of grip/performance. For instance Continental slicks (by Hoosier) is almost as fast (a slightly harder compound) than the R6s we toyed with.

I ran full slicks in my E36 M3 back at Yas Marina for a while and it behaved very much like a Hoosier. You NEED to bring them up to temp, whereas the A6 are ready to assault from the get go. 800/900 f/r spring rates though. HUGE difference in grip vs general R Comps like RA1, Pilot Cup, we experienced a 5 sec delta in a sub 2 min track. Here's a video (Euro motor 321hp M3) walking away from GT3 RS, CSL M3s, Scuderia Ferrari:

The Pirelli slicks on the Aston GT4 and the Radical pretty much behaved the same. Took a while to get heat in them, I took a passenger out in the Radical once and spun (embarassing) the first turn.

Long and short, you will get differing answers. Even in the slick word, there are soft/medium/hard compound much like we have the in R Comp world.

The Hankook C90 and the R/A7 are much closer to slicks (in my opinion they are rebadged slicks vs DOT R).

The DOT Hoosier/Hankook is more of a US thing, ROW (Europe/Middle East etc.) race tires = slicks.

Lutfy

[G-Man]

Originally Posted by Lynxis

DOT slicks are, technically, legal to drive on the street. Not that you'd want to because the compound isn't designed for it though

I know at least for the NCCC autocrosses the stock class is "street legal tires" and these are a way people get around that rule and still ran slicks. I would guess they were designed specifically for "Street tire" classes. The SCCA added the treadwear rating limits to stop things like that.

[rx3]

Yes, in Europe we don't have any DOT slicks.
So I wouldn't have a comparison, but I guess that they are faster (otherwise Autocrossers in the US wouldn't run Avons).

I've been running Michelin (S5B) and Avon (A11). Both are sticky from the beginning but can overheat quickly. Ideal for Slalom and Hillclimbs.
On the very first run, the Michelin are faster than on the subsequent runs and are faster than the Avons. After the first run the Michelin and Avons are about the same. It's also noticable that the Michelin slicks are particularly light (much lighter than street tires).

(Pirelli, Hankooks and Yokohoma are also available but are not available in such soft compounds as the Avons and Michelins. Well Pirelli has a soft compound but not in all sizes.)

[Silver Supra]

Originally Posted by Lynxis

DOT slicks are, technically, legal to drive on the street. Not that you'd want to because the compound isn't designed for it though, they won't get warm enough for decent grip and they'll wear too quickly.

As for the differences between the DOT slicks and real slicks, I don't know but I understand that DOT slicks are considered the last step before going to a full slick.

Yes, DOT slicks can be driven on the street but the only time I do that is if I want to go off track site to get gas (much cheaper). I think there may be more difference between different tires and compounds than there is between DOT and non-DOT slicks.

[Robbie]

Originally Posted by Captain Snooze

This is just a curiosity question; I am not considering putting slick slicks on my car (although I do use DOT slicks).

What difference is there in construction, grip, performance, compromise between a DOT slick such as Hankook Z214, Kumho V710 and a proper racing slick?

Now that I mention it what does the DOT actually mean considering DOT slicks aren't for road use?

Actual "slicks" are much lighter than DOT R tires because they do not need to have as robust belt construction in order to meet blowout standards. They also can have less tread depth, thus generating less heat from squirm. Many non DOT slicks are bias ply construction, meaning less camber is needed and the tire wants a lot more slip angle than a radial slick or radial DOT tires.

The DOT mark is just saying that a tire passes the minimum DOT specification for blowout resistance and tread depth along with having minimum tread "blocks". This is because SCCA had a DOT requirement for a large number of autox and race classes. Hoosier, and others have designed race tires that meet DOT specifications, but are not really meant for the street, which is what the spirit of the DOT rules were supposed to be way back in the day.

However, R compound tire manufacturers put the "not for street use" to cover their asses for people who would try to drive them on the street and get in an accident due to hydroplaning.

[ka-t_240]

Originally Posted by G-Man

I know at least for the NCCC autocrosses the stock class is "street legal tires" and these are a way people get around that rule and still ran slicks. I would guess they were designed specifically for "Street tire" classes. The SCCA added the treadwear rating limits to stop things like that.

Stock class used to allow any DOT tires.

Stock class is no more. They are now called "street" class, and must have a 200tw+ tire.