And for those who are reading along but haven't driven on the Star Spec/Z2/Rival/etc... they're pretty equivalent to an RA-1 but won't chunk at full tread. Nobody has been able to get these tires to cycle out before they wear out. Shaving yields minimal improvements as there's not a ton of void area in the first place (unlike the Toyo RA-1: see also, chunking at full tread). A FWD car with ~125whp @ 2300-2400 race weight is getting 24+ hours on track out of a set of 205/50 15 or 225/45 15 tires.

Think of them as a longer lasting and almost as good NT-01 for even less money.

Peak G-loads are in the ~1.3-1.4 range with sustained G's in the 1.1-1.2 range... a couple tenths below a Hoosier and just a touch below the RA-1/NT-01/R888.