Just did my first day at HPR this past weekend and had a blast. The elevation changes really add an extra layer of fun to the track.
My car was on RE71R 245/45/17 with stock alignment. No mods other than wheel/tires and high temp brake fluid (stock brake pads). Unfortunately my car hit limp mode during my fourth session (ambient temps around 65F).
The track was crowded enough that I only really got 3 clean laps the whole day, but I managed a 2:08.
With a more aggressive alignment, I think a 2:06 should be possible!