So based on your research in GT4 you think it will do 7:40....LMAO
snicker snicker.
I think the C6 Z will be hard pressed to beat the old GT2 Porsche's number of 7:44. I dont know where you even begin to mention the CGT in this comparison. It will be more comparable to the GT2 times. It will no know doubt be faster than the old Z.
If it does do a 7:40 or better like you predict it would be nothing short of incredible, and may put an end to the "American cars a straight line cars" bs.