COld/wet weather road legal track day tyre

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I'm continuing my new-found addiction to track days through the winter and am unhappy with my current Toyo T1Rs. A recent outing to Brands with track temperature around zero all day, and rain on-off thru the day, convinced me to look around for a better cold-weather road-legal track tyre. Having looked around the forum, and tyrereviews.com, I've narrowed it down to the following tyres;

Kuhmo v70A - K21 soft compound - these appeal as they seem widely available in various compounds.
Toyo R1R
Yokohama Advan A07s
Michelin Pilot Sport

However, most of the reviews I've seen are by road drivers, not track drivers.

I'd be grateful for any feedback from experienced track drivers who've used any of these tyres regularly on cold or cold/wet track days - when the temperature is in the range of 0-10 degrees? And for any alternatives I may not have considered.

The car is a Mini Cooper S remapped to 240bhp, KW coilovers, Alcon brakes, Team Dynamics, 225/45/R17, roll cage etc.

Thanks

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gruffalo said:

The Kumho's are my general tyre of choice, brilliant on my car in the dry with huge grip once warmed up for a lap. In the wet it just frustrates me, I can't explore the upper half of the Rev range at all without lighting up the rears,

Thanks - Any idea what compound you were using on the Kumhos?

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radical78 said:

what car do you have yokahama AO21R work really well on alight car(caterham) but might warm up and feel squirmy on a big heavy saloon

Its a mini cooper S bumped to 240bhp - 17 wheels, unfortunately the AO21R's only go up to 15" - thx

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Having made a decision, here's some feedback:

In the end I opted for the Michelin Pilot Sport 3 tyres as the feedback on various forums seemed very good.

Took the mini to Brands last Sunday and it was a different vehicle with the Michelins in place of the Toyo T-1Rs. Track temp at 10am was about 4-6c, tyre temp was 10-15c after driving to the track for 30 minutes.

Morning session was just damp enough to throw up some light spray for the first hour or so, and no dry line. Tyres were really very good, no squirming, lots a grip on the front, and rear felt solid the whole session. Tyre temps were getting up to 30c after a few laps. Lapping about 3-5s faster than with the Toyo's. Cars on semi-slicks seemed to be struggling a bit.

Afternoon session track started to dry out, the sun came out, a continuous dry line emerged. Track temp rose to 10c, tyre temps up to 50c after a few laps. Tyres were really very good, huge amounts of grip around Clearways - afternoon lap times 5 seconds off the morning times.

By mid-afternoon spotted some other cars trying out slicks, so the whole cold/wet/damp tyre choice debate became irrelevant, but at least the new tyres performed well first thing.

I've found the whole tyre choice question to be a huge mystery. One well known retailer suggested semi slick Kumhos for winter track driving, while another well known retailed point-blank refused to sell me any tyre for that purpose, claiming no tyre that he sold was manufactured for track driving in the winter. Tyre manufacturers themselves seem to provide very little info on optimal operating temperatures and optimal operating conditions. I guess that's for a reason - presumably they sell more tyres that way, or maybe its just commercial secrecy. Anyway, hope my feedback is of some use to other relatively inexperienced track drivers.