HKS Technical Factory in Japan has been doing some testing and upgrades on the Nissan GT-R Spec V. On paper the Spec V costs a lot more than the regular GT-R, and offers little performance increases in the engine compartment. However, it seems something is hiding within the turbochargers.
The Spec V turbos are 3 mm bigger on the inlet side of the compressor and 4 mm larger on the exducer side of the compressor. The exhaust side exducer is about 8mm larger which will give this turbo reduced backpressure, and the reduced backpressure will turn into more top end power. HKS TF took a Spec V added the GT600 kit with larger injectors and fuel pump and at 1.4 –1.5 kg/cm2 of boost saw 730 ps or about 720 horsepower. There was no mention in the article if this was at the wheels, or at the engine horsepower.
For those people wanting to purchase the Spec V turbochargers, the price comes in at 1,000,000 yen each, or about $10,900 each . This puts them out of most “reasonable” peoples price range. HKS TF is working on their own upgraded turbos, that will have a similar compressor wheel to the Spec V turbocharger, but with a cutback normal GT-R exhaust wheel. They expect them to be able to provide 650-680 hp.
|Number of blades||12||12||12|
|Number of blades||9||11||9 + cutback|
Source : GT-R Blog – GTR-World