Kinugawa Turbo TD Series Line-up Code Explained

Kinugawa TD series turbocharger part numbers encode the turbine wheel frame size, compressor wheel type, turbine housing area, and optional suffixes for wheel width and rotation direction. This guide decodes every element of the naming convention so you can identify the right turbo for your application.

What Does the Kinugawa TD Series Code Mean?

The TD prefix stands for Turbine Driven. The number following (e.g. 04, 05, 06) designates the turbine wheel frame size class. Additional letters and numbers specify the compressor wheel, turbine housing, and configuration.

1. Turbine Housing Sizes: cm² to A/R Conversion

Kinugawa turbine housings are rated in cm² throat area. The table below converts these to the A/R ratios commonly used with Garrett turbochargers.

TD04-based turbochargers use 5–7 cm² turbine housings. TD05 series turbochargers typically use 6–10 cm² housings.

2. Compressor Wheel Types: G, T, GK, TK, KX Series

Kinugawa compressor wheels are identified by a number (specific wheel) joined with a letter (blade arrangement or trim). The main series are:

• G series: Alternating blade heights and fin curvature — standard performance design.
• KX series: Latest generation, CNC point-milled with 3rd-order free surface geometry for maximum efficiency.

Free Surface (Point Milling) vs Ruled Surface (Flank Milling)

3. Turbine Wheels: TD04 vs TD05 Compatibility

Any TD04 series compressor wheel fits any TD04 series shaft — whether TD04H, TD04HL, or TE04H. TD04 and TD05 compressor wheels are not interchangeable due to the difference in shaft hole diameter. Sleeving a TD05 wheel onto a TD04 shaft is possible but requires precise balancing; an oversized wheel risks shaft failure or uneven bearing wear at high speeds.

3.1 Turbine Wheel Frame Characteristics

3.2 What Is STS (Superior Turbine Strike) Technology?

The STS turbine wheel builds boost 5–8% faster than a standard 11 or 12-blade STD turbine. It achieves this through lower inertia, reduced restriction, and higher flow capacity. Three generations are available:

• STD (11–12 blades): Standard turbine wheel — baseline performance.
• STS (9 blades, Journal Bearing): 5–8% faster boost build, extended choke area, higher top-end speed.
• STS Advanced (9 blades STS or 10 Blades STS 55, which comes with ceramic Dual Ball Bearing): 10–15% faster boost response vs STD, improved shaft dynamics, greater durability under sustained load.

What Is the STS 55 Turbine Wheel?

The STS 55 uses a patent-pending splitter-blade design to reduce exhaust manifold pressure (EMAP) by operating at a lower expansion ratio. Key benefits:

• More horsepower and torque — reduced backpressure allows the engine to breathe freely.
• Higher volumetric efficiency — lower EMAP improves air/fuel ingestion and throttle response.
• Reduced knock sensitivity — lower EMAP permits more aggressive tuning.
• Lower exhaust gas temperatures — reduced thermal stress on engine components.

The STS 55 achieves the high flow of a low blade-count turbine while maintaining the efficiency of a high blade-count design — eliminating the traditional trade-off.

STS Advanced: Ceramic Dual Ball Bearing Explained

The STS Advanced replaces the journal bearing with a ceramic dual ball bearing system. Inner and outer races with ceramic balls replace oil as the primary shaft orientation control — reducing friction, improving response by 10–15%, and extending service life under high-load conditions. Oil lubrication is still required.

4. Compressor Maps: TD02 to TD08

The compressor map below shows the flow range and pressure ratio for each TD series frame — use this to match the right turbo to your target power level.

5. Enhanced Internal Spare Parts

6. Crank Horsepower Range by Frame Size

Use the chart below to identify which TD series frame matches your target crank horsepower. Downloadable in A3 and A4 formats.

7. Actual Case Study: Mazdaspeed 3 / 6 MZR DISI 2.3L Turbo Upgrade

The Mazdaspeed 3 and Mazdaspeed 6 MZR DISI 2.3L platform is one of the most instructive real-world examples of how the TD series frame selection directly determines power ceiling, spool character, and reliability. The factory turbocharger — a BorgWarner K04 variant (K0422-881 / K0422-882) — is rated for approximately 260–280 WHP and fails predictably above 21 PSI due to its 270-degree thrust bearing and undersized turbine exducer. The following case study applies the TD series selection framework to this platform across three power tiers.

For the full engineering analysis of the OEM K04’s limitations and the complete system integration guide, see: Best Turbo Upgrade for Mazdaspeed 3 & 6 MZR DISI 2.3L — Full Engineering Guide →

7.1 Platform Baseline: OEM K04-882

Parameter	OEM K04-882
Compressor Inducer / Exducer	45.0 mm / 56.25 mm
Turbine Inducer / Exducer	50.1 mm / 44.5 mm
Blade Technology	Cast 12-blade
Bearing Type	Journal — 270° thrust pad
Turbine Housing	Small A/R (tight)
Max Reliable Output	~260–280 WHP
Primary Failure Mode	Thrust bearing wear above 21 PSI; turbine seal oil leak

7.2 Tier 1 — Street Build: TD05H-18G (350–400 WHP)

The TD05H-18G is the direct bolt-on replacement for the K04. It retains full compatibility with the stock exhaust manifold and downpipe flanges while delivering a 12% larger compressor inducer area and a 21% larger exducer diameter. The 360° thrust bearing eliminates the K04’s primary failure mode. The STS 9-blade turbine wheel reduces EMAP and builds boost 5–8% faster than the OEM 12-blade unit.

Parameter	TD05H-18G
Compressor Inducer / Exducer	50.3 mm / 68.0 mm
Turbine Inducer / Exducer	56.0 mm / 49.2 mm
Turbine Housing	7 cm² / AR.49 (Mitsubishi-derived)
Blade Technology	Billet 6+6 or 11+0 compressor; STS 9-blade turbine
Bearing Type	Journal (360°) or STS Advanced ball bearing
Target Output	350–400 WHP
Inlet Size	OEM (bolt-on, no intake modification required)

TD series code applied: TD05H frame + 18G compressor wheel + 7 cm² turbine housing = TD05H-18G-7cm

7.3 Tier 2 — Built Engine / Aggressive Street: TD05H-20G 3" Anti-Surge (450–500 WHP)

The TD05H-20G steps up the compressor inducer to 52.3mm, extending the efficiency map to support 25–30 PSI without superheating the intake charge. The 3" ported shroud (anti-surge) compressor cover prevents surge at low RPM by recirculating excess air — critical on a 2.3L engine where the larger compressor wheel can outpace engine demand at low speeds. The turbine housing remains 7 cm² / AR.49 for street-friendly spool.

Parameter	TD05H-20G 3" Anti-Surge
Compressor Inducer / Exducer	52.3 mm / 68.0 mm
Turbine Inducer / Exducer	56.0 mm / 49.2 mm
Turbine Housing	7 cm² / AR.49
Compressor Cover	3" ported shroud (anti-surge)
Blade Technology	Billet 6+6 or 11+0 compressor; STS 9-blade turbine
Bearing Type	Journal (360°) or ball bearing
Target Output	450–500 WHP
Intake Modification Required	Yes — 3" intake system to match compressor inlet

TD series code applied: TD05H frame + 20G compressor wheel + 3" anti-surge cover + 7 cm² turbine housing = TD05H-20G-3"-7cm

7.4 Tier 3 — Track / Competition: TF06-18K Ball Bearing 4" (550+ WHP)

The TF06-18K represents the top-tier application of the TD series framework on the Mazdaspeed platform. The TF06 frame uses a larger bearing housing than the TD05H, accommodating a 55.1mm / 75.0mm billet 7+7 point-milled compressor wheel and a 61.5mm / 54.0mm turbine wheel. The 4" anti-surge inlet eliminates surge entirely at high boost. The STS Advanced dual ceramic ball bearing reduces spool time by 10–15% versus the journal bearing variant and is mandatory for sustained high-boost track use.

Parameter	TF06-18K Ball Bearing 4"
Compressor Inducer / Exducer	55.1 mm / 75.0 mm
Turbine Inducer / Exducer	61.5 mm / 54.0 mm
Turbine Housing	Mazda-specific flange
Compressor Cover	4" ported shroud (anti-surge)
Blade Technology	Billet 7+7 point-milled (KX series); 9-blade turbine
Bearing Type	STS Advanced — dual ceramic ball bearing
Target Output	550–600+ WHP
Intake Modification Required	Yes — 4" intake system

TD series code applied: TF06 frame + 18K compressor wheel + 4" anti-surge cover + ball bearing CHRA = TF06-18K BB 4"

7.5 Full Specification Comparison: OEM K04 vs Kinugawa Upgrades

7.6 Mandatory Supporting Modifications

Regardless of which tier is selected, the following supporting modifications are required on the MZR DISI 2.3L platform:

• HPFP Internals (Mandatory for all tiers): Autotech or CorkSport — the stock high-pressure fuel pump cannot maintain rail pressure above stock airflow levels. A lean condition under boost causes immediate detonation and engine failure.
• ECU Tune (Mandatory for all tiers): Cobb Accessport or Versatuner — required to rescale MAF calibrations, adjust load targets, and optimize ignition timing for the new turbo’s efficiency islands.
• Downpipe: 3-inch high-flow or catless — minimizes post-turbine backpressure and allows the STS turbine to extract maximum exhaust energy.
• Intercooler: FMIC or upgraded Top Mount (3.5" core) — the stock TMIC heat-soaks under increased mass flow, raising intake temps and triggering knock retard.
• Intake: 3" (Tier 2) or 4" (Tier 3) intake system to match the compressor inlet diameter.
• Oil Feed: Journal bearing units — -4AN feed line, no restrictor. Ball bearing units — 1.0–1.5mm restrictor orifice mandatory to prevent bearing flooding.
• Oil Drain: Must be vertical within ±15°. Any uphill section causes oil to back up into the CHRA and leak into the exhaust.
• Boost Control: 3-Port Electronic Boost Control Solenoid (EBCS) for precise boost management.

WHP figures are flywheel estimates based on compressor choke flow. Actual results depend on engine health, fueling, tuning, and supporting modifications.