Truthfully, my experience is with a fast street car on street tyres your times are actually quicker on the street than a prepped track.
My previous GTR never turned all four tyres in THIRD gear on the street but consistently did on Willowbank's prepped surface.
My theory is that on a smooth prepped trach a street tyre cannot "key" into the texture like it can on the street. Hence, a slick tyre is what you really want for a prepped track.
Regardless, 2.9 to 100,..... man, wow, that's fast!