HKS Upgrade Kit - Super Street Magazine

Seibon Nissan 370Z
While the GT-R seemingly holds the crown as the family jewel, the 370Z is definitely breathing down its bigger brother's neck. The GT-R is the supercar of the family and that designation also means that it is less accessible to the public. The price tag alone makes it a bit of a reach for the everyday average enthusiast, so the 370Z might be the vehicle of choice between the two, just based on the extra $30K you would have in your pocket to build yourself a GT-R killer.

The latest rendition of the 370Z is not only the most powerful of all the Fairlady Zs, it is also the best equipped to compete with its bigger and badder brethren. Engine size is nearly the same and both sport the latest and greatest technology from Nissan engineers. The main difference between the two lies in the twin-turbo set-up featured on the GT-R's VR38DETT engine. Seibon's R35 also has the HKS Upgrade Kit that bump horsepower numbers up over 550 and the only way the 370Z can compete with that is if it were also boosted. That is where GReddy Performance Products come into play. Their newly developed twin-turbo kit gives the Seibon 370Z 175-plus extra horsepower at just 6 pounds of boost! GReddy assures us that with a little bit more work and tuning, the twin TD06SH-20G turbos have the potential to make over 850-plus horsepower. While you may be thinking that a simple turbo upgrade would easily get the R35 over that 850-horsepower hump, consider this: the stock turbines of the VR38 engine are actually integrated into the exhaust manifolds and are one unit to decrease weight and promote vehicle balance. A simple turbo upgrade, in essence, wouldn't be simple at all because it would require new exhaust manifolds as well. The whole process would then be similar to installing a completely new turbo kit. More fabrication and development means a higher asking price for any sort of turbo upgrade. In this instance, the edge for ease of modification would definitely go to the 370Z.

Everything unrelated to the aesthetics of the Z were all developed in house at GReddy's facilities. This meant that no outsourcing was necessary for engine management as this 370Z receives all brain function from a GReddy e-Manage Ultimate ECU. The new fuel system is also GReddy-made as is the dual SE exhaust system.

Suspension and brakes, as you might expect, are also pure GReddy productions. They have supplied Seibon with their Type-S fully-adjustable coilover suspension and stopping power comes by way of GReddy's 8-pot front/4-pot rear brake system. Housed over the larger brake rotors are the same wheels found on the Seibon Edition GT-R: 20x10'' and 20x11'' RAYS Engineering VR.G2s. The 370Z is able to accept such an aggressive wheel set-up thanks to 10mm-widened Seibon carbon-fiber fenders.

The 370Zs are much lighter than R35s but that doesn't mean that it shouldn't shed a few pounds. The Seibon GT-R dropped quite a bit of weight with all the carbon-fiber goods and this 370Z follows suit. It features Seibon's very own NS-style aero kit which utilizes a carbon-fiber front bumper that mimics styling cues from the GT-R. The sides, rear lip, hood and rear hatch most are certainly Seibon carbon-fiber components. Though it may not have that supercar reputation, it definitely makes up for it in the tuning potential department. Doing anything to a GT-R would require a pretty large chunk of change and parts aren't always as readily available compared to the Z. You really have to ask yourself if the R35 is worth double the asking price of a Z34. The Fairlady Z is also a purebred two-door sports car by definition. It still hold similar styling cues which pay homage to the Fairlady Zs of year's past and still retains a true manual gearbox, which has been omitted from all current generation GT-Rs. The thought of not being able to drive stick in a sports car would drive some people nuts!