I am running the same setup and am having pretty good luck with Subcultures when the track is holding a lot of moisture (first and second rounds usually). If it dries up to the point of having a light dust in the groove, I'll finish up with Gridirons. Temps here in the mid-west are starting to get pretty cool and the track is holding moisture longer. I often go out and touch the track in between rounds to get a feel for what tire is needed