The theoretical max speed of a 6 speed Lan Evo VIII GSR is 165 mph
I used the following for my calculations, Tires are 235/45, 17 inch rims, 7000 rpm redline, final gear of 4.583 and a 6th gear of 0.693.
The equation is pretty simple (assuming the car has enough horsepower to accelerate to and maintain the speed at redline)
Tire diameter which is [(235*0.45) * 10 * 2] + [17 * 2.54]
and the rotational speed of the tires at engine speed of 7000 rpm
Tire diameter turns out to be 2.02098 meters and rotational speed of 2204 rpm or 132241 rph
2.02098 * 132241 = 267256.5 meters per hour or 267.2 kph which is 165 mph
=D so thats the theoretical max speed of the lan evo VIII GSR 6 speed =D
and just outta curiosity i figured the theoretical max speed of the s2000 as well, it is 250 kph or 155 mph