Street tires in IT? My Review

[Chip42]

As promised, I ran a set of 205/50R15 Dunlop Direzza ZIIs at Sebring for the traditional Thanksgiving weekend "Turkey Trot" races 11/30-12/1. My car is a mild prep ITB MR2 at 2335 min weight, about 2340-2380# as raced depending on fuel load.

the rain gods were unhappy with us, and every time our group was headed to grid the skies would start to spit on us - just enough to make everything slick, not enough water to exploit the treads on the Dunlops. oh well. so I didn't really develop a feel for the tires until the races on sunday, the later of which started dry.

My impressions:
little to no noise. none of that 1982 showroom stock tire howl many people seemed to expect.

amazing braking feel. I could lock them up but it wasn't like I was constantly feeling for that line. 9/10ths driving there was no issue, 10/10s it was still impressive how much brake I could use.

Cornering grip is certainly less than a hoosier, but I think the marked difference is a slightly slower response time to inputs on the wheel. I wasn't logging actual Gs but I didn't feel wanting. slip angles were obviously higher, and I found myself throwing a lot more at the wheel than I would normally with hoosiers. simple to get used to, and it was fun chucking the car around a bit. optimizing the suspension and alignment for these tires would help, with near zero toe the car was a bit floaty. shaving the tread might help response but goes contrary to my experiment to evaluate the tires as delivered.

They are very linear - breakaway is not sharp, though it is still sudden. recovery is easier than on a hoosier for this reason.

speed - I'm no SARRC champ but I was able to keep up with the same pack of cars I usually run with, and actually made up ground in the corners as usual for my rather underpowered car. I honestly don't think I was more than 2s off my personal Hoosier pace.

overall I really enjoyed them. more forgiving, require a bit more input, handle great, and feel very racy. At roughly half the price of a set of R6s in the same size... I'm a convert.

I ran Street Tire Challenge livery on my hood that will match the decals I'll be offering for IT racers in the CFR, or other divisional/regional series that wish to make use of them, to run a race within a race for IT cars - 100% optional, scored separately by volunteers, not the local SCCA event organizers, so it's invisible to the T&S folks and thus easier to implement on the fly. 100% IT rules with an added 180+ tread wear minimum to the tire rules. sign up, slap on a sticker, go have fun.

current offerings in popular IT sizes that fit the bill are the ZII I ran along with the BFG Rival, Hankook RS3, and Yokohama AD08R. there are some others in fewer sizes and I'll bet more are on the way.

stay tuned for more on the Street Tire Challenge series. I urge everyone to try these out, I think you'll be surprised how good they are. I think they are likely to be farther off the pace as the class speeds go up, so ITS might be 5-6s a lap off, where ITB is maybe 2-3s.

anyhow, I'd like to hear other's impressions. I think these have the potential to make for a lot of fun, lower cost racing.

[Knestis]

Good feedback here. I'm looking forward to seeing how the Challenge works out!

K

[quadzjr]

This same weekend I pulled the older 195/60x14 dunlop Z1 tires off my street car. They were a lot of fun. I was unable to get any real comparable data as the runs were in the damp and the reat was on new 225 R6. I hope more regions think about it. There was a decent group of people that came by and was interested. Ranging from ITS to ITC. Not many ITR cars there.

I plan on getting a set of Z2s or rivals and run cfr races. Hoosiers are great but if you are not getting contingency (finishing position or lack of competitors) then this is a great solution.

[Flyinglizard]

Congrats on your win!!

I have a pile(20+) of 205/50/15 Dunlops. Z1, 160$ for 4. some are very nice. The new Z2 are supposed to grease up more than the last version. I dont know for sure tho.
The new Chumper needs some 265x 17s.

Add the HP class to the ITA cars and I'll bring a Golf. It wont keep up with the ITA cars tho but I can try.

[Chip42]

I'm not getting into class mix n' match. if you want to run the HP car on 180s, we can work a group for that, but it'd an ITX or SPU, not an ITCS class.

they really were impressive though. to bad I wasn't as much, but cobwebs and all that.

[Matt93SE]

FWIW we run the Rivals on our crapcan Miata, and I'm happier with them than I am Z1s in the same size. we ran a full 24hr event and used up maybe 25% of the tire. I never ran that car with DOT-Rs, but I was quite happy with how it handles on the Rivals and was keeping up with well-known SM builders & racers in their 'cheater SM car'. (they were also on Rivals).