A rough translation of some basic technical guidelines of the All-Japan Grand Touring Car Championship (JGTC): "If it is the production engine of the identical manufacturer with the based vehicle, it can load even with those of another model."
While there are few things more amusing than poorly translated Japanese, the point is that JGTC cars can use any engine from the same manufacturer as the body. The various teams competing in the series have utilized this rule in a variety of creative ways. For example, Toyota Supras do not house the 3.0L 2JZ-GTE motor installed at the factory, but a 2.0L 3S-GTE borrowed from an MR-2. A few hundred million yen helps to negate the power given up by the decrease in displacement, but the real benefit is that the four-cylinder weighs less, and when nestled far in the rear of the engine compartment, distributes weight better. Neat trick!
Nismo has also done its share of swapping in its Nissans. Until recently, its GT500-class Skyline GT-Rs raced with the same RB26DETT found in all recent generations of GT-Rs, from R32 to R34. But starting with the new R35, making its U.S. presence felt as the Infiniti G35, the Skylines have forgone the I-6 in favor of a V-6.
Nismo seems to be getting a head start on the new car by getting to know the new engine. The results are promising. We can see the improvements of the V-6 even on paper-a lower height and a shorter length. With those differences, the center-of-gravity is shifted lower and toward the core of the car, reducing polar inertia, and most importantly, lap times. In addition, Nismo reports that the VQ platform loses little power to friction, has highly efficient combustion, and is more durable than the RB.(I dunno. I'm pretty durable.-RB)
From a distance, Nismo's JGTC cars look fairly similar to their mass-produced counterparts, but only because the rules dictate it. Beneath their racing paint is a carbon-fiber skin, and you can imagine where it goes from there-definitely not a daily driver. It's too bad and Top Secret agrees. They've taken this new powerful fusion of R34 and VQ30DETT to create the closest thing to those race-winning machines that will never see public asphalt.
The nucleus of this hybrid, the motor, is normally found in some of Nissan's most luxurious sedans. Think along the lines of the new 4.5L V-8 Infiniti M45, which in Japan is known as the Nissan Gloria and gets its pep from a VQ30DET. This motor migrated under the hood of a Skyline in Top Secret's workshop, and promptly sprouted an extra turbo, and another "T" in its designation, now VQ30DETT.
Turbos get quite hot, but both Nismo and Top Secret have found that another benefit to this amalgamated engine bay are the new options for routing cooling equipment. Instead of having to block the radiator with an intercooler, there is now enough room to fit all that aluminum in a tidy sideways V shape. Air enters the car's mouth (the open end of the V), then flows into each pane of vanes, escaping out the other side through ducts in the hood and front lower diffuser. Predictably, there's yet another improvement to be found: less aerodynamic resistance due to air being split in a controlled way over and under the car, rather than tumbling through the engine bay.
Get ready for another bad translation: "As for drive system, when the 4WD standard it is equipped in the based vehicle, as for modification to the 2WD it is free."