in Theory, no 2 drivers are the same... Drivers had different preference on settings, if the nsx-r is set as its liking, then he would be able to push harder. (or vice versa) I do understand that Street car, no matter how fast it seems, the Professional Race drivers can push to their limit and reveal some sort of the car's ability. but numbers do not tell stories. That's why when you 'read' a respectable magazine and Best Motoring, you should pay more attention of their comment and the articles. Numbers does not mean anything.
I'm assuming... even the Z06 (C5) had the equal time as NSX-R at Nurburing, the way they drive and where they make up the time should be quite different.
Now as much as I love my nsx, and worshipped the nsx-r 's goddess.... I don't think it stand a chance against the C6 Z06, unless GM really messed up with their numbers.
Lets do some bench racing, I believed the Nsx-R is less than 300 lbs slimer than the Z06. But the Z06 does have bigger and meatier tires, and more than 200 hp, not to mention low end torque.(sorry don't have the figure, but I have no doubt it'll have almost too much
) If the car does not have much taller gearing than our garden variety US spec nsx. It will eat the nsx-R alive. I based my assumption on the 200hp vs 300 lbs weight saving.