2005 WRX STi Build Update

Here at EDO Performance, revealing true performance is something we do best. Being the first year of the facelift to the second generation Impreza, “blob eye” Subaru models gained a highly praised following subsequent to the earlier “bug eye” Imprezas. Welcoming the ‘WRX STi’ name to the family came a “blob eye” Subaru such as this one. In the famed World Rally Blue Pearl paint, with the most powerful motor available at the time, this STi in even its stock form is still an amazing machine on the streets. However for some it will eventually become time for a power upgrade. At this point there are options to choose from, those being either buy a new car or make your current one faster. An amazing factor of the Subaru platforms is that they can be made to take more power for a relatively reasonable price compared to buying an entirely new car! We’re not talking about just an ECU tune either.

“With great power comes great responsibility” said the late Ben Parker. Anyone can get a tune and up their boost or even swap out a turbo. It’s all fun and games until someone blows a motor so with that said, there are safer and wiser steps to adding more power. Beginning with the basics we started by checking and making sure this STi’s motor was ready to take on the modification process. Checking for things like oil leaks, boost leaks, cracked hosing or pipes, ignition components and more, this Subaru was ready for its journey down the path of safe and reliable power. This kind of build was to be prepared as a track capable motor. Keeping this in mind we knew the main issues that had to be addressed when it comes to car problems on the track. Sticking to the engine side of things, we wanted to make sure that this car would be able to stay cool under heavy driving and high heat conditions.

Power was to be primarily attained by this STi from the Tomioka Racing GT35 Turbo. A .82 AR Stainless Steel Turbine Housing with 3” V-Band inlet and outlet utilizes genuine Garrett ball bearing technology and with its compressor wheel improves air flow by at least 10%. All around the GT35 is a great turbo for those looking for top end power. If the V-Band inlets and outlets aren’t suitable however, T3 inlets are also available. Of course connecting this turbo setup to the STi meant also upgrading a few other components that equip directly to the turbo assembly. Tomioka Racing’s unequal length exhaust manifold with 3-bolt up-pipe, Tial MV-R 44mm wastegate and Tial Q 50mm blow-off valve with 11 psi spring, and Mishimoto front mount intercooler, aluminum coolant expansion tank, and ancillary hoses,  all work in unison to make sure that this STi will be creating boost and horsepower effectively, efficiently, and safely.

To give a custom touch and assure functionality, EDO Performance doesn’t step down when there is a need for custom modification and fabrication. Keeping the turbo working properly is essential so that meant for a custom turbo feed return line as well as the turbo flange and gasket themselves. Regardless of fluids and conditions, there is no avoiding that heat will sit underneath the hood so to make sure there isn’t any heat escaping from the turbo application; a custom carbon fiber blanket was created. Proper fitment for functionality and maintenance is always kept in mind during modification and fabrication at this level so keeping that in mind all stainless steel piping and upper and lower radiator hoses are made accessible.

Turbo systems are complicated on their own and require a unique system of parts. After creating the entire custom turbo setup for this STi, we pursued other sources of reliable power. In simple terms, installing racing camshafts in this Subaru allowed for a higher curve, bigger valve opening, more air/fuel, more combustion, and more power. To provide and feed the engine with the amount of fuel it now -needed we installed Injector Dynamics 1700cc fuel injectors, a Walbro in-tank 400 lph e85 fuel pump and Tomioka Racing pro series fuel pressure regulator. Air and fuel need to be under constant monitoring from the cars ECU, but this can get a little tricky for the car as modifications are added. AEM Electronics’ air inlet temperature (AIT) sensor and Omni Power 3 bar map sensor help with this ensuring that the ECU knows the proper amount of air and fuel to supply the engine with based off of the custom tune we applied. Thanks to a K&N Air Filter, the engine and turbo system attains a crisp, cold, and clean source of air.

Adding many more components that consume electricity meant that this STi needed a suitable power source. The highest reserve capacity and cold cranking amperage is provided from the TR-B2100 battery. Tomioka Racing’s battery utilizes Absorbed Glass Mat (AGM) technology which increases specific power and ride quality and environmental safety. The design allows the battery to be mounted in a variety of positions and to accept automotive terminals vertically and horizontally. Included with each Tomioka Racing battery are quality brass SAE terminals, designed to distribute the electrical load battery for high amperage, high stress use of racing and audio applications.

We at EDO Performance are excited for this build to reach its completion so that we can witness yet another satisfied customer and experience one awesome and brutally fast street machine! Stay tuned!

Like what you see? Get it for your car today!

• Tomioka Racing .82 AR Stainless Steel Turbine Housing 3” V-band inlet & outlet (Turbo: GT3582)
• Tomioka Racing Subaru Single Scroll Unequal Length Exhaust Manifold w/ 3 Bolts Up-Pipe for EJ20/EJ57
• Tomioka Racing Universal Fuel Pressure Regulator (Pro Series)
• Tomioka Racing High Performance Light-Weight Battery
• Tomioka Racing 8” J Hooks w/ Bolts
• AEM Electronics Air Inlet Temperature (AIT) Sensor
• Tial MV-R 44mm Wastegate
• Tial Q 50mm Blow-Off Valve 11psi Spring (Blue)
• Injector Dynamics 1700cc Fuel Injectors for Subaru WRX 02-11 / STi 07-11
• Walbro Universal In-Tank 400lph E85 Fuel Pump (w/ Install Kit)
• Omni Power 3 Bar Map Sensor