Tomioka Racing TD05-20G Bolt-On Turbocharger — 2002-2007 Subaru WRX / 2004-2021 STI
The Tomioka Racing TD05-20G is the most popular turbocharger upgrade for the Subaru EJ platform. The 52.5 mm inducer compressor wheel provides meaningfully more airflow capacity than the TD05-18G while retaining the responsive, daily-drivable street character the GD platform is known for. Rated to 450 HP — the definitive street/track bolt-on upgrade for GD WRX and STI builds.
DETAILS
- Platform: 2002-2007 Subaru WRX EJ20/EJ255 and 2004-2021 STI EJ207/EJ257
- Journal bearing construction
- Compressor: 52.5 mm inlet / 68 mm exducer
- Turbine: 56 mm inlet / 49.2 mm exducer
- Turbine housing: 8 cm²
- Actuator: 1.1 bar / 16 psi
- Max. power: 450 HP
- 100% bolt-on — standard Subaru 5-bolt flange
- Complete kit included
| Bearing Type | Journal bearing |
|---|---|
| Flange Type | Standard Subaru 5-bolt |
| Compressor Inlet | 52.5 mm |
| 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 | 450 HP |
Turbocharger Design and Specifications
A journal bearing turbocharger uses a hydrodynamic oil film to support the rotating shaft. The oil film provides lubrication and a degree of compliance, requiring oil pressure to build before full-throttle use and a brief cool-down period after hard use before shutdown. Journal bearings are proven and durable — TR journal bearing turbos use the standard Subaru 5-bolt flange and include all oil and water connections for direct installation at the factory turbocharger location.
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 TD05-20G is the definitive street/track turbo upgrade for GD WRX and STI — the most popular option because it delivers the right balance of peak capability and street usability. At 450 HP with strong mid-range and top-end delivery, it represents the best balance for GD EJ builds targeting serious performance without sacrificing daily drivability.
Fitment
| Year | Make | Model | Notes |
|---|---|---|---|
| 2002-2007 | Subaru | WRX | EJ20/EJ255 MT |
| 2004-2021 | Subaru | WRX STI | EJ207/EJ257 MT |
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