To date, Ive ran on track with OEM tires (IRC, not V rubber), pirelli diablo rosso, kenda KD1, and now on PMT after pushing to the limits of the KD1's.
OEM IRC, surprisingly good tire! great in the rain, knee down no problem wet. ran pretty respectable lap times on a mostly stock/slightly modified grom and Z125 pro. rubber got slippery when pushed hard and they did start to melt on the edge..pressure adjustments helped but as good as they are, they are still a street tire.
Pirelli's, better than the IRC, but not by a large margin. grip with low heat, and very sensitive to the right pressures. when pressure was wrong they overheated quickly and started melting.
Kenda KD1 Kwick, outstanding tire for price. but noticeably a heavy tire. very slick out of the box before scrubbed in though..like dangerously so...do a few laps and lean a little more each time before digging in. these tires helped me get down to some pretty quick kart track lap times and really push hard through corners. I ran a range of pressures 18 to 25..sometimes a bit lower just to try for more grip but they seemed to be roughly the same in that range for me. Once I got to their limit... I was able to have predictable, controlled slides both front and rear..sometimes at the same time...but at that pace....that was it..for me the tire was the limit.
PMT's now much lighter weight than Kenda's...medium front/rear, currently at lap record pace on local Kart track for bike class, they are doing their job for sure. no warmers yet but def. in the cards for longevity and reduced heat cycles. I have had them slip a time or two, but more due to rider error and aggressive steering input than tire limit I think. I am sure there is more to be had still from these..
always ran 120/100 tires aside from break in miles on new bike first set of IRC stock size... quickly changed to used set of IRC that I had from the Z125 pro for quicker turn in... the wider tires stock on the grom made it super dull and slow to turn in.