The A7's are not a great choice for track days. Specifically designed for autoX, they are designed to reach operating temp quickly and for short periods of time. From personal experience, at a track day they are good for a lap or maybe two, then go off quickly. I found on the A7's, we are getting about 25-35 heat cycles, before ultimate grip starts to be compromised (in autox). Not that they stopped working or were worn out, they just didn't stick as well as when they were new. R7's are a better choice for the track days, although not sure about how they handle multiple cycles, as I have only run them a few time myself and haven't completed a full season yet (although, given the "R" designation, I suspect they are ok). They feel much better at a track day, and unless it's brutally hot (like Africa hot), they maintain their grip through the 30-45 minute sessions.
Haven't run Hoosier slicks, but I know with my Goodyear's and Michelins, 4-5 heat cycles and they were done. And noticeably done.....similar to hockey pucks or plywood or studded winter tires skittling across the pavement.
On a personal note, if you aren't looking for ultimate grip, I'd definitely look at the R888, the RE-71R or the Starspec. Excellent grip and the added bonus of having decent grip in the rain.
*Edited for atrocious grammar)
Last edited by fivendime; 05-05-2017 at 11:03 AM.