Ten years ago, tuning a Japanese import was a very challenging task. For one, there were few mechanics in the States that knew anything about improving the performance of a Honda, Mitsubishi, Toyota or Nissan. If you had the money and the contacts, your best investment was to purchase tuning parts from a full-line Japanese performance-parts manufacturer. Back in 1996, HKS and GReddy were the only two Japanese performance parts manufacturers that catered to the U.S. market.

Today, much has changed. Subaru now offers one of the most popular tuning platforms in the form of the Subaru Impreza WRX. There is now a plethora of readily-available performance parts for today's popular platforms. The U.S., Australia and Japan lead the way in manufacturing high-performance products for Japanese imports. Over the past ten years, more Japanese companies have come to the U.S. market including A'PEX Integration, TOMEI, TEIN, DEFI, BRIDE and Tanabe. Now, the latest influx of specialized performance parts is coming from the brand-specific manufacturers of Japan. ZERO/SPORTS is one of these application-specific manufactures from Japan that focuses on Subaru performance parts. Recently, ZERO/SPORTS became available in the U.S. through EDO Performance of Houston, Texas (with a satellite office in Huntington Beach). This recently-built demo car showcases the ZERO/SPORTS GD-chassis lineup.

Rolling Display

Instead of building a dedicated time-attack car, the crew at EDO Performance decided that a dual-purpose street/track vehicle would be more beneficial. In this way, the Subaru could act as a rolling display on daily commutes while still being able to run some respectable times at track events. This configuration allows EDO Performance's Sales Executive Louie Shiu to enjoy her drive to work in her STi. With 93-octane pump gas in the tank and the low-boost maps selected on the Turbo XS UTEC engine-management system, the STi has perfect street manners. When the STi visits the track, tuner Miguel Alcrudo Jr. also takes on the driving duties. With VP Racing Fuels C16 race gas in the tank and the boost set to 27psi, 450 horsepower at the wheels allows the ZERO/SPORTS-equipped demo car to stretch its legs.

Performance Recipe

Have you ever eaten at an expensive restaurant only to leave hungry? The crew at EDO Performance wanted this buildup to satisfy the performance appetite of most enthusiasts without putting a major strain on the wallet. While more performance could have been obtained with a stroker engine and bigger turbo combination, EDO Performance realized that most enthusiasts have a fixed budget. With that in mind, attention turned to strengthening the EJ257's weakest links while improving the performance with a variety of bolt-on performance parts.

The engine that now resides under the hood of this STi features nothing more than Cosworth 8.5-to-1 forged-aluminum pistons and ARP head studs. Since the weakest link (the factory pistons) is now replaced, the engine is strong enough to handle the 450 wheel horsepower generated as a result of the performance bolt-ons.

In looking over the bolt-ons, the combination is quite simple. This EJ257 engine features a turbo upgrade, fuel system upgrade and an engine tuning solution. A ZERO/SPORTS exhaust manifold directs the high-enthalpy exhaust gases into a ZERO/SPORTS Venturi up-pipe. The up-pipe directs the exhaust flow into the 8cm2 turbine section of the Forced Performance TD06H turbocharger (FP-Red). As the turbocharger's rotating assembly is put into motion by the energy contained in the exhaust gases, the compressor pushes air into the top-mount TurboXS intercooler. Once the desired boost level is realized in the intake manifold, the spent exhaust gases are expelled through a TiAL Sport 44mm wastegate and TurboXS bellmouth downpipe. While the upgraded turbocharger is supplying the necessary airflow to produce 450whp, the upgraded fuel system provides the fuel necessary to reach this power level. A Walbro 255lph in-tank fuel pump sends the fuel forward to the SARD adjustable fuel-pressure regulator and Perrin Performance fuel rails. A quartet of 850cc/min Power Enterprise injectors take cues from the TurboXS UTEC engine-management system that's been tuned by Miguel.

Fancy Footwork

While 450whp allows this boxer to sting like a bee, it definitely makes it more of a challenge to float like a butterfly. To carve canyons and road courses alike, this STi relies on a full complement of ZERO/SPORTS suspension enhancements. ZERO/SPORTS 23mm sway bars at the front and rear help to keep body roll to a minimum. A set of ZERO/SPORTS WinningR coilovers ensure that the contact patch provided by the Hankook Ventus C70 tires is maximized. The lightweight 18x9-inch 5Zigen FN01-RC wheels reduce unsprung weight and rotating mass to deliver improved handling over the bumps.

Lasting Impression

To provide an upgraded look on par with the performance improvements, this Subaru features a ZERO/SPORTS complete body kit. ZERO/SPORTS bumpers and side skirts tie in perfectly with the SEIBON carbon-fiber hood. A ZERO/SPORTS rear-roof vane is also on call to improve aerodynamics while adding to the vehicle's unique look. Inside the cockpit, a Cusco six-point cage and Takata four-point harness add some safety while the Sparco Pro2000 seat keeps the driver in place. DEFI BF Gauges (boost, EGT, fuel pressure) mount in an ATI center meter pod while a DEFI VSD displays vehicle speed on the windshield. Just above the steering wheel, a PLX Devices R-300 wideband A/F monitor relays real-time air-fuel ratios. With this hardware in place, the driver always has his or her finger on the pulse of this Subaru's engine.

For more on this article and more grab a copy of DSport Magazine on newsstands and tuning shops nationwide!