You should go and pick up a copy of the February 2008 copy of Option Magazine. Hiro the editor in chief just sent me a copy because there’s a feature of Cosworth in it. Aside from the fact that there’s a bitchin feature of Cosworth in it (and a picture of yours truly with a stupid ass smile), the main focus of this issue is the R35 GT-R. There’s also a R35 GT-R catback exhaust test in it where some shop fabricated a titanium catback exhaust and the car made 507.9ps (500.95hp) at the flywheel. Granted, this test was conducted on a Dynapack so it probably read 5% or higher than any other dyno, but the gain of 22ps is for real. If you can’t do the math, that’s 485ps from the factory which is pretty god damn buff already considering the car is rated at 480hp at the flywheel. The boost went up by 0.1kg/cm^2 (1.42psi) due to the reduced backpressure, but this also tells you that the car has some serious potential from the factory. By looking at this exhaust I can guarantee you that it’s louder than hell so I wouldn’t expect a 22ps gain on a production catback exhaust though. Excuse the shitty scans…
Click here to see the dynograph. Power is at the FLYWHEEL.
Here you can see the boost increase from the exhaust.
It looks like Nissan calibrated the fuel map to go leaner after peak torque. This is done to increase peak horsepower and is probably fine at low boost and horsepower levels where the cooling effect of a rich mixture is not necessary. Keep in mind that Nissan is shooting to compete with supercars so they need that peak horsepower number so rich baller dudes can tell their buddies, “It makes 480hp. That’s the same horsepower as your Porsche 997 Twin Turbo for $60k less!!!”. The R35 is buff.