it comes down to the level of development that has gone into that 34 GTR
On one side, the v8 supercars are limited by their class
(eg limited to 5 litres, RWD, Live Axle)
but on the other side, it would take a hell of a R34 GTR to beat one of the quicker Supercars around a circuit.
in the end, the two cars are not in the same class so the question is irrelevant