a standard NEW T3 will do 15-17 psi for quite a while..no probs...

however one thats done 60k or so miles on std boost (8 psi) if you turn that up to 15 psi it wont last too long,

imo, a T3 should have a 360 degree thrust bearing fitted instead of the std 270 degree and then it will do alsorts of silly boost for some time at least