Bust out the DependsTM adult underwear because this Silvia is playing for keeps. The well-crafted speed demon embodies the "aim high" philosophy of Kazama Auto Service in Kasugabe-City, Saitama Japan. By definition, a time attack car is a purpose-built vehicle but Kazama narrowed its focus with laser-like precision when it created this S15 Silvia specifically for battle at Japan's famed Tsukuba circuit. The bull's eye? Generate a laptime of less than 60 seconds with only two liters of displacement under the hood. The Silvia is familiar territory for the Kazama crew as the company campaigns an S15 in the D1 Grand Prix drift series. Only a slight alteration in mindset was needed, namely, tune for grip instead of slip.
Kazama produces its own lineup of trick suspension components designed to allow the suspension to contort like a Cirque du Soleil performer. At the core of the Kazama line is adjustability, the over-adjustability of toe-in, camber, ride-height and the often-overlooked steering needed to maneuver sideways at 60 mph. The Tsukuba Special runs a Kazama pillow tension rod that replaces the stock rubber bushing with a solid spherical ball end that enhances rigidity. Custom control arms add strength and lightness to the suspension while a Kazama toe control arm allows complete adjustment of the Nissan's toe setting, which enhances its turn-in response. Tanabe Sustec Pro Seven coilovers are the centerpiece of the set-up and are used with the Tanabe Electronic Active Suspension (TEAS) that allows programmed adjustments of damping characteristics based on entry and exit speeds and other parameters.
Response is only part of the picture. You need superior mechanical grip, braking power and straightaway speed to put together a sub-minute lap at the famed Tsukuba circuit. Mechanical grip comes from Goodyear rubber, with compound selection being dictated by track conditions. The car runs a staggered set up with 17s in front and 18s in back, all wrapped around Gram Light wheels. Stopping power has been addressed with six-piston Endless calipers and mondo-sized rotors up front and a Brembo upgrade out back.
To close the deal, a time attacker needs bodacious boost screaming though a bulletproof powerplant. The Silvia is blessed with one of the all-time great turbo four engines: the SR20DET. Internally, the stout SR was readied for boost abuse with only 86mm HKS pistons, the rods were deemed up to the challenge. The goal in mind was around the 500 horsepower range. With that number in mind and the high engine speeds that the engine will endure the crank was dynamic balanced.
The pressure player is an HKS GT-series 3037S turbo. As with all GT series offerings, the 3037S features a full ball bearing center cartridge that allows the selection of a turbo that provides a bit more top without hurting response. The compressor housing checks in with a .60 A/R, which is the norm in the GT line.