More info courtesy of KyleEggspuehler21:
This is from a guy we race with named Charlie. The tires are (Y) rated which is 186+. Charlie is the most senior racer in the ORR scene. Here are some answers straight from him:
Here are a few answers to your questions.
Tires. Michelin Pilot Sport PS2s. Front 275/35ZR18 rear 335/30ZR18
Purchased in Feb '12. Were on their second (last) year of ORR use.
Have been using the PS2s since '07 with no problems. The first tire failure resulting in an off road incident in '04 was with Hoosiers.
Although the RPM indication went to zero when the tire blew, this was due to the electrical shutoff being tripped which caused the data panel to see no signal which is zero RPM. The engine did not "lock up" but was "dead" just as if you had turned the ignition off.
The data panel continued to function since it is powered by a dedicated battery.