This baby has been around. From auto shows across the nation and races on both sides of the Pacific, Signal Auto's S15 Silvia has logged more travel miles than an Aerosmith groupie. We caught up with Kousuke "The Mad K" Kida and the Signal Auto crew after the Osaka Auto Messe, a trade show on par with the Tokyo Auto Salon.
Kida started out as a street racer, but soon turned to sanctioned racing. He set up shop more than 10 years ago in Osaka and expanded into the United States with Signal Auto USA. The company made a name for itself with its famous candy orange tuned cars. Its motto is "tuning for everybody without fear or prejudice," and its versatility shows in the range of cars and races it has worked on.
This S15 returned to Japan from the United States in late '03. As an "Option" magazine project, the S15 went a whopping 194.72 mph at the Bonneville Salt Flats in Utah. Unsatisfied with the results, Signal took it to the races in the United States. In the NHRA Street Class, the S15 clocked an 11.2-second quarter mile.
Then Signal entered it in a couple of drifting competitions, with Kazuya "Chunky" Bai behind the wheel, including the first D1 Grand Prix held at Irwindale Speedway in August, 2003.
The S15 is powered by a Nissan SR22DET four cylinder with a monster turbo that puts out 560 hp. A SARD fuel regulator and two Bosch fuel pumps regulate the juice that supplies 850cc injectors. Engine operating parameters are controlled by a Signal-tweaked HKS F-CON V Pro computer unit. The bulk job was done with a Toda 2200 kit that upgraded the original Nissan SR20DET to a SR22DET. The added displacement was achieved by upping the bore to 87mm and the stroke to 92mm.
The S15 is armed with Tomei rocker arm stoppers, Toda camshafts with 68 degrees of duration and 11mm of lift with a Toda valve guide and slide pulley. An A'PEXi 1.8mm head gasket keeps the cylinder pressure inside the engine. Signal made the finishing touches and polished up the port.
A Trust exhaust manifold with 45mm-diameter runners feeds a Trust T88-33D turbo kit. A Trust/GReddy PRofec boost controller keeps the boost in order, while a Trust three-layer intercooler increases the density of the boost charge as it makes its way into the engine.
Lastly, a Trust Type R blow-off valve regulates pressure on the cool side while a Trust Type R wastegate controls boost on the hot side.
Signal's partner, Exedy, provided the carbon-based twin-plate clutch that connects the SR22 to a Trust six-speed sequential transmission outfitted with an ARC cooler to ensure a long and fruitful life. A Trust carbon driveshaft and a Cusco Type RS LSD (final gear rate 4.3) were installed to control the differential motion. Most drifters prefer this type of LSD because it delivers traction and control on the edge.
The suspension consists of a Tanabe R/R damper kit augmented with a 14kg full pillow-ball-height adjustment setup, which helps tailor suspension performance to the car's job of the day, be it drifting, time attack, street cruising or drag racing. An ARC titanium strut bar was mounted to enhance rigidity no matter what angle the g-forces hit from.