Motohiro Matsumura, president of Nissan Technical Center North America, says the claim that the GT-R develops 430 hp at the wheels, is basically RIGHT. But he insists the estimate of a minimum 15percent friction losses, which suggests the GT-R is making 510-520 bhp, is WRONG.
Well, the issue here is how much power is lost in converting from flywheel power (“brake horsepower” = circular) to “wheel power” (longitudinal). To be precise in terms, let’s call this power loss “parasitic losses”, or “PL’s” for short. Anyway, PL’s in cars come from u-joints, friction in the various connecting points, etc, and are compounded when the joints and tubes deviate from perfectly straight.
Matsumura-san says ultra-low friction bearings in the wheel hubs and transmission, plus the careful alignment of the AWD system’s propshafts, mean friction losses are reduced to an unprecedented 10 percent or so. Guess what? That figure validates their power claims of 480HP. Great engineering and great job.
My understanding from Nissan engineering is that because there are so many opportunities for PL in an AWD car, they went to great lengths to reduce the PL loss factor. They also used exotic materials like carbon fiber, and most significantly, they achieved nearly linear alignment of all this. So the usual 20-25% losses once normally sees do not apply here.
This explains why ALL GT-Rs are required to come in for ‘inspection’ after a certain KMs to ‘realign’ the shafts and transmission. This is exactly the reason why Tan Chong can’t bring in GT-R at the moment, they don’t have facilities to carry out the works.
