Tomioka Racing TD06-20G Billet Twin Scroll Turbocharger — 2008-2014 Subaru WRX / 2005-2009 Legacy GT
The Tomioka Racing TD06-20G Billet Wheel Twin Scroll for the 2008-2014 Subaru WRX, 2008-2014 Forester, and 2005-2008 Legacy GT combines twin scroll spool speed with billet compressor efficiency — at least 10% better airflow over the standard wheel. Rated to 550 HP at 640 cfm. The largest available bolt-on for these applications in a twin scroll configuration.
DETAILS
- Platform: 2008-2014 Subaru WRX EJ255, 2008-2014 Forester EJ255, 2005-2008 Legacy GT EJ255
- Billet compressor wheel — minimum 10% airflow improvement
- Twin scroll turbine housing
- Journal bearing construction
- Compressor: 52 mm inlet / 68 mm exducer (billet)
- Turbine: 61 mm inlet / 54 mm exducer
- Turbine housing: 8 cm²
- Actuator: 1.1 bar / 16 psi
- Max. power: 550 HP / 640 cfm airflow
- 100% bolt-on — standard Subaru 5-bolt flange
- Complete kit included
| Bearing Type | Journal bearing (billet compressor) |
|---|---|
| Flange Type | Standard Subaru 5-bolt |
| Compressor Inlet | 52 mm |
| Compressor Exducer | 68 mm |
| Turbine Inlet | 61 mm |
| Turbine Exducer | 54 mm |
| Turbine Housing | 8 cm² |
| Actuator / Gate Pressure | 1.1 bar / 16 psi |
| Max. Power | 550 HP / 640 cfm |
Turbocharger Design and Specifications
Billet compressor wheels are machined from a solid forged aluminum billet rather than cast, giving a more consistent grain structure throughout. Tomioka Racing uses point-milling on billet blades, allowing the cutting tool to reach precise geometry between blade profiles — creating surface finish and blade profile accuracy that casting cannot achieve. The improved geometry directly contributes to compressor efficiency and durability. A twin scroll turbocharger divides exhaust pulse inputs into two separate scroll passages. On a four-cylinder engine, pulses from cylinders 1 and 4 enter one scroll while pulses from cylinders 2 and 3 enter the other. Keeping these paired pulses separated ensures each arrives at the turbine wheel with higher energy and less interference. The result is improved exhaust scavenging efficiency, more consistent turbine loading, and faster spool speed compared to an equivalent single-scroll design.
Installation, Kit Contents, and Wastegate Spring Guide
Each Tomioka Racing turbocharger kit includes all hardware needed for 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 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.
Choose 1.1 bar (16 psi) if your boost targets include values below approximately 22 psi, or if you run multiple maps including a low-boost street mode.
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. Better control stability at higher targets and better resistance to premature wastegate opening under high backpressure.
As a general guideline, peak target boost should not exceed approximately 2x the gate pressure for stable boost control authority.
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 TD06-20G Twin Scroll for the GR WRX and EJ255 variants is the maximum-capability bolt-on for these applications — twin scroll spool speed, billet compressor efficiency, and TD06-20G power capacity in one direct-fit unit. At 550 HP and 640 cfm, it extracts the maximum from the GR EJ255 stock turbocharger location.
Fitment
| Year | Make | Model | Notes |
|---|---|---|---|
| 2008-2014 | Subaru | WRX | EJ255 MT |
| 2009-2013 | Subaru | Forester XT | EJ255 |
| 2005-2009 | Subaru | Legacy GT | EJ255 |
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