Road racing an R35 Nissan GT-R is a battle in cooling. The R35 is a 3800 lb car without driver, makes at least 480 horsepower, and is all wheel drive. This puts some unique strains on the systems in the car. From the engine oil, to the front differential, coolant, transmission, rear differential, and brakes, everything needs cooling when you run the car hard. If you aren't overheating the systems in a R35 GT-R, you aren't driving it hard enough for long enough. Nismo produces an R35 RC - Super Taikyu endurance race car that you can purchase and go racing.
|420 mm front rotors 6 piston monoblock calipers|
In order to go fast on the track, you need to be able to slow the car for corners.You have to be able to do that for every corner, every lap, lap after lap. The stock CBA GT-R has 380 mm x 34 mm rotors on the front which are very large for a street car. The Super Taikyu car has gone 40 mm larger to accommodate a 420mm rotor. The above rotors sure look like AP Racing J-Hooks. They use a very large hat, with a fairly small friction surface. No weights are available, but they are probably not too much heavier than the stock rotors and hats. Not as light as a set of 400mm carbon ceramic matrix (CCM) rotors.
|Carbon fiber front bumper with brake cooling ducts|
|Brake cooling ducting|
Look how thick the brake pads are in this caliper setup. Lots of pad means more time between pad changes in endurance racing. The brake lines are from Goodrich with heat sleeving on them. The same brand that the STILLEN brake lines use without the heat sleeving. Only one of the two possible duct to hose transisions are being used in the above picture.
|Carbon fiber air deflector|
At the rear of the car, Nismo uses a simple air deflector arrangement to direct air at the factory rear caliper, with specialized rear hats and rotors.
|Rear brake caliper with customers hat|
The rear hat looks aluminum, unlike the factory iron piece, with an offset in it so the car can use the same wheels and tires on the front and rear. 20 x 10.5 x+ 25 offset.
|20 x 10.5 x+ 25 Volk G2 wheels|
|Front differential cooler and power steering cooler|
On the left front side of the car, there is a front differential cooler, and a power steering cooler. This is opposite of what most Nissan GT-R owners and shops do in the USA and Japan. We see several companies that put either a transmission or additional oil cooler on the left side. Nismo does not, and it is worth noting. The front differential is on the side of the oil pan, and reports from people at Nissan say the front differential heats the oil. Cooling it, helps keep the oil cooler.
|Rear differential cooler|
At the rear of the car, there is a differential cooler with a simple duct running to it. Mizuno has mentioned it several times, that the differential in the R35 gets very hot, and this contributes to heat in the transmission. Transmission heat is something that most owners that track their GTR seem to battle. The way that it is tried to keep under control is to install a transmission cooler , like the GREDDY kit. . This race car does not have a seperate transmission cooler. They do run a large radiator, and the radiator is used to cool the transmission. They also probably run a cooler thermostat, and that could help to keep the transmission cooler.
Nismo knows these cars, and has access to a lot more data than most tuning shops, or owners will ever have. Even if you can't afford to buy their car, you should have a look at what they do to cool the car, and take some notes. They will probably head you in the right direction.
Source and Pictures: GT-R World