Tomioka Racing Billet TD05-18G Turbo - 2002-2007 Subaru WRX / 2004-2021 STI

Tomioka Racing Billet TD05-18G Turbocharger — 2002-2007 Subaru WRX / 2004-2021 STI The Tomioka Racing Billet TD05-18G for the 2002-2007 Subaru WRX and 2004-2021 STI uses a lighter, stronger billet compressor wheel — rated to 440 HP with a street/track balance. Handles mid to high-end horsepower without significant lag time compared to the stock turbo, with the additional efficiency and durability of billet construction. DETAILS Platform: 2002-2007 Subaru WRX EJ20/EJ255 and 2004-2021 STI EJ207/EJ257 Billet compressor wheel — lighter and stronger than cast wheel Journal bearing construction Compressor: 52.5 mm inlet / 68 mm exducer (billet) Turbine: 56 mm inlet / 49.2 mm exducer Turbine housing: 8 cm² Actuator: 1.1 bar / 16 psi Max. power: 440 HP 100% bolt-on Complete kit included Turbocharger Specifications Bearing Type Journal bearing Flange Type Standard Subaru 5-bolt Compressor Inlet 52.5 mm (billet) Compressor Exducer 68 mm Turbine Inlet 56 mm Turbine Exducer 49.2 mm Turbine Housing 8 cm² Actuator / Gate Pressure 1.1 bar / 16 psi Max. Power 440 HP Turbocharger Design and Specifications Billet compressor wheels are machined from a solid forged aluminum billet rather than cast. Cast wheels have the grain structure of the pouring and solidification process — adequate but limiting stress tolerance and blade geometry precision. Billet wheels machined from forged billet have a more consistent and favorable grain structure throughout. Tomioka Racing uses point-milling on their billet compressor wheel blades, a machining process that allows the cutting tool to reach precise geometry between blade profiles, creating surface finish and blade profile accuracy that casting cannot achieve. The improved surface quality and geometry directly contribute to compressor efficiency and durability. Installation, Kit Contents, and Wastegate Spring Guide Each Tomioka Racing turbocharger kit includes all hardware needed for the installation: the turbocharger unit, wastegate actuator, oil feed and return pipes, water cooling connections, all gaskets, and the hardware kit. All current production TR turbos include a billet wastegate actuator. Professional installation is recommended for turbocharger swaps — the oil feed and return line routing, water cooling connections, and boost line setup all require attention to detail for correct long-term function. For DCBB turbos, a Turbosmart TS-0811-0012 OPR V2 Turbo Oil Pressure Regulator is recommended to ensure correct oil pressure at the bearing unless otherwise noted.Wastegate Spring Selection: 1.1 bar vs 1.3 bar The actuator spring sets the gate pressure — the minimum boost the turbocharger will produce. You cannot run boost lower than the spring rating regardless of ECU or boost controller settings. Choose 1.1 bar (16 psi) if your boost targets include values below approximately 22 psi, or if you run multiple boost maps including a low-boost street mode. The 1.1 bar spring provides good boost controller authority across a wide operating range. Choose 1.3 bar (19 psi) if your minimum target boost is 19 psi or higher and your normal target is in the 22-28 psi range. The 1.3 bar spring provides better control stability at higher boost targets and better resistance to premature wastegate opening under high exhaust backpressure conditions. As a general guideline, peak target boost should not exceed approximately 2x the gate pressure for stable boost control authority from the solenoid. What's in the Box Turbocharger Billet wastegate actuator Oil feed pipe Water pipe Gaskets Hardware kit Why Choose Tomioka Racing (TR) Tomioka Racing has been building direct-fit turbocharger upgrades for Subaru performance vehicles since the early 2000s. Every TR turbocharger is engineered around the factory connection points — oil feed, water cooling, mounting flange, and charge pipe inlet all match OEM positions — so installation is genuine bolt-on without custom fabrication. TR covers the full span of EJ-series and FA-series Subaru platforms, from the GC8 through the current VB WRX, and their turbochargers are proven in both street and motorsport use including rally racing. Each kit ships complete with turbocharger, actuator, oil pipe, water pipe, gaskets, and hardware — everything needed for the swap in one box. RallySport Direct stocks the full TR turbocharger catalog because their engineering quality and fitment accuracy are what our customers expect. The RallySport Take The TR Billet TD05-18G for the GD WRX and STI is the premium street/track turbo for GD owners who want 440 HP capability with daily-driver responsiveness and the durability of billet construction. Fitment Year Make Model Notes 2002-2007 Subaru WRX EJ20/EJ255 MT 2004-2021 Subaru WRX STI EJ207/EJ257 MT