With my stocks on I ran 36psi and had good 60' times with them. Usually around 1.90's. The DR's I run around 27.5 psi and my tread use is about an inch in on the sides. I could run lower psi and get all the tire on the ground, but the hoosier DR's are rounded towards the edges. I have ran at 16 psi and as high as 38 psi, both felt like I was a little squirly at the top end. I didn't like skating around and my 60' times weren't any better. So I have stayed with 27.5 for DR's and 36 for stocks. Be Safe and Have fun.
Cruzinquick

Sidenote: this was with temps from the 50's to 70's. As it gets hotter I will see if this psi still works.