I read this somewhere:
"just read the feb issue of excellence (Porsche Magazine) which compares the two on track at infineon raceway driven by johannes van overbeek (Porsche driver). gt2 1:49.2 and vette 1:48.8. states run flats on vette and r compound on porsche probably reason was so close."
Somewhere else the times are different: Porsche GT2 1:49.2, ZR1 1:48.1
Anyone knows more? Can someone enter the times?