Hoosier Bias Ply Front Runners

[MAG5OH]

Ok so I pulled the trigger and bought some 17"x4.5" and 17"x9.5" Racestars with 27.5x4.5x17 bias Hoosier Front Runners and 28x10x17 Hoosier slicks for my soon to be Twin Turbo 2016 GT. Obviously for the rears I will start in the high teens for pressure and see what works the best. My question is what kind of pressure should I do for the fronts on a full weight S550? I wont be driving on the street with these but just want to have a good starting point.

Thanks!