Hard to say. I don't know the speed of a race GTR to start with, 130- 170mph? And then the downforce and gearing would play a big part. I suppose the lowish speed is because road car engines have overtaken race FIA engines. So a BTCC or WTCC car may not be as high as a Porsche GT2 or GT3 RS road car or even and R8 road car
Having said that i would prefer a drive in the M3 GTR and a ride home in the Porsche :icon_thumright:
The crunch of the gear changes is great when its up loud.