fritz:
Jean:

I see the weight of GT-R complained quite often.

However, according to Mizuno san the weight figure was part of the whole packaging from the very beginning of GT-R's design.

He explains "based on his experience with the relationship between the down force weight and tire patch grip of Group C race cars, the weight of GT-R has been predetermined to achieve optimal tire patch grip in a road car.  The light weight packaging simply could not provide enough grip without using softer tire compounds.  To achieve the maximum grip in all situation with NORMAL road tires, the GT-R's optimal weight for its tire compound has been determined without increasing the downforce that involved enormous drag coefficient."

First, I thought what a bullocks he's talking about, but the more I think about it, it makes more sense in a road car with road tires.  It's no wonder this car is so quick when it corners.

I suspect that your first thought was right, and that Mizuno-san was indeed talking a load of young male cattle. Smiley

If tyres cannot build up enough grip because there is not enough weight on a given tyre patch, that is, the pressure (force[weight] per unit area) on that patch is too low, then the answer is surely to reduce the area of the tyre patch, not to increase the vehicle weight.  Apart from instances of ballast being used to alleviate problems resulting from poor suspension geometry or weight distribution, this is the first instance I remember hearing of where the weight of a car has been increased to improve its dynamic performance. Smiley

Hi Fritz,

In the world of physics, I think you are correct.  

But, how about standing start for 3 sec run with over 500hp or high-speed cornering?  Wouldn't the reduced tire patch negatively affect this?

Perhaps for a road tire that has to last certain mileage (hard compound), maybe there is an optimal weight that maximizes the potential of the tire friction value of this 4WD machine?