Tomioka Racing S55 Twin Turbo Kit for BMW F8X M2 Competition, M3, and M4

Tomioka Racing (TR) S55 Twin Turbo Kit

 

Complete bolt-on twin-turbo upgrade for the BMW F8X S55 platform.

Building More Power From the BMW S55 Platform

 

The BMW S55 engine is one of the most capable modern turbocharged inline-six engines from BMW M. Found in the F80 M3, F82 M4, F83 M4 Convertible, F87 M2 Competition, and F87 M2 CS, the S55 responds extremely well to proper tuning, fuel system upgrades, charge-air cooling, exhaust flow improvements, and turbocharger upgrades.

For owners looking beyond basic bolt-ons and ECU calibration, the factory turbocharger system eventually becomes one of the major limits in the power curve. As airflow demand increases, exhaust backpressure rises, intake temperatures become harder to control, and turbocharger efficiency becomes more important.

The Tomioka Racing (TR) S55 Twin Turbo Kit is designed as a complete turbocharger upgrade for S55-powered F8X BMW applications. With an 800+ HP-capable design, ball bearing turbochargers, matched exhaust manifold, front and rear compressor intake pipes, oil and water lines, gaskets, and installation hardware, this kit provides a serious foundation for high-output S55 builds.

The turbo kit is only one part of the equation. To safely reach higher horsepower levels, the rest of the vehicle must be prepared to support the airflow potential.

 

Vehicle Fitment: S55 Applications Only

 

This kit is specifically designed for BMW S55-powered vehicles.

Fits:

• BMW F80 M3
• BMW F82 M4
• BMW F83 M4 Convertible
• BMW F87 M2 Competition
• BMW F87 M2 CS

Does Not Fit:

• BMW F87 M2 with the N55 engine
• BMW G87 M2 with the S58 engine

The standard F87 M2 uses the N55 engine, while the M2 Competition and M2 CS use the S55. The newer G87 M2 uses the S58 engine, which has a different turbocharger system architecture. Before ordering, confirm both the chassis and engine code.

 

Why Upgrade the S55 Turbo System?

 

Factory turbochargers are engineered for broad drivability, emissions compliance, packaging, noise control, and factory reliability targets. They are not necessarily optimized for sustained high-output builds. As power goals increase, the factory turbo system can become restrictive in several areas.

1. Compressor Flow Limitation. Higher horsepower requires more air mass. If the factory compressor wheel is operating near the edge of its efficient range, intake air temperatures rise and the turbocharger has to work harder to maintain boost.

2. Exhaust Backpressure. At higher boost and airflow levels, exhaust-side restriction becomes a serious limitation. Excessive backpressure can reduce efficiency, increase heat, and limit top-end power.

3. Heat Management. Turbocharged engines generate significant heat under sustained load. A performance turbo kit needs to support airflow while also considering manifold temperature, oil supply, coolant routing, and surrounding component protection.

4. Transient Response. A larger turbocharger can support more peak power, but response still matters. A properly matched turbo system should also deliver usable boost response during street driving, track use, and acceleration transitions.

The TR S55 Twin Turbo Kit is designed to address these areas with higher-flow components and a ball bearing turbocharger design.

 

Ball Bearing Turbocharger Design

 

One of the key features of the TR S55 Twin Turbo Kit is its ball bearing turbocharger design. Compared with traditional journal bearing turbochargers, ball bearing center sections can reduce friction and improve shaft response. In practical terms, this can help the turbocharger respond more quickly to exhaust energy, improving spool behavior and transient response.

For an S55 build, that matters because the goal is not simply to chase a peak horsepower number. A strong turbo upgrade should deliver improved airflow capacity, better high-rpm power potential, stronger response during throttle transitions, reduced lag compared with poorly matched oversized turbo setups, and better efficiency under higher boost targets.

The TR kit uses a dual-ceramic ball bearing design, making it suitable for performance builds where response and durability are both priorities.

 

Compressor and Turbine Wheel Specifications

 

The TR S55 kit uses the following wheel specifications:

 

The compressor wheel sizing is intended to support increased airflow demand over the factory turbochargers, while the turbine side is designed to help move exhaust gas efficiently through the system. The kit also features a high-flow 9-blade turbine wheel, which improves exhaust-side flow — important because the turbine side directly affects how efficiently the engine can evacuate exhaust gas while driving the compressor wheel.

 

How the TR Turbos Compare to Factory

 

The factory S55 runs twin Mitsubishi TF035HL4W turbochargers. Here is how the TR units compare:

 

The TR turbos are larger on every measurable axis — compressor, turbine, and housing — which is what enables the higher airflow ceiling.

 

Larger Turbine Housing and Airflow Efficiency

 

The TR S55 Twin Turbo Kit uses a larger turbine housing to support increased airflow demand. A larger housing can help reduce exhaust restriction at higher power levels, which becomes especially important when targeting aggressive horsepower numbers.

The key is balance. Too small, and the turbo becomes restrictive at high rpm. Too large, and spool and drivability suffer. The TR S55 kit is positioned as a high-output twin-turbo solution for builds targeting serious power while still maintaining responsive performance when paired with the right fuel, tuning, and supporting hardware.

 

What's in the Box

 

• TR twin turbochargers (ball bearing)
• High-temp coated exhaust manifold
• Front turbo compressor intake pipe
• Rear turbo compressor intake pipe
• Oil feed pipe
• Water (coolant) pipe
• Gaskets
• Hardware kits

Note on the actuator: An actuator is not included with the kit. The factory actuator transfers over from your stock turbochargers and is reused on the TR units. Plan for this during installation and inspect the actuators for proper function before tuning.

 

What You'll Still Need (not included)

• ECU calibration / tune — required; not included
• High-flow / reduced-restriction exhaust path
• Upgraded intercooler / charge-air cooling
• Charge pipes & boost control hardware [confirm whether solenoids/BOV are needed]
• Fueling upgrades (injectors, HPFP support, flex fuel hardware as required by target)
• Spark plugs gapped for boost
• Crank hub solution (strongly recommended for aggressive builds)

A complete kit reduces the need to piece together separate turbo-side components and helps create a cleaner upgrade path, but fitment, oil supply, coolant routing, gasket sealing, and compressor inlet flow all still affect installation quality and long-term reliability.

 

Manifold and Thermal Durability

 

The included exhaust manifold is an important part of the system. In a turbocharged engine, the manifold must handle extreme exhaust temperature, pressure pulses, and vibration. The TR kit includes a high-temperature manifold coating designed to improve durability under performance driving conditions — especially relevant for cars used in aggressive street driving, roll racing, track events, or repeated high-load pulls.

Thermal management is not just about protecting the turbocharger. It also helps protect surrounding components, reduce heat soak, and support more consistent performance.

 

Intake Pipes: Front and Rear Compressor Flow

 

The S55 twin-turbo layout requires dedicated compressor intake routing for the front and rear turbochargers, and this kit includes both a front and a rear turbo compressor intake pipe.

The compressor inlet side directly affects turbo efficiency. Restrictive intake routing can make a turbocharger work harder to achieve the same boost pressure, while cleaner inlet flow can improve compressor efficiency and help the system perform more consistently at higher airflow levels.

 

What Does 800+ HP-Capable Really Mean?

 

The TR S55 Twin Turbo Kit is designed to support 800+ HP-capable builds, but the turbo kit alone does not automatically make 800 horsepower. Final power output depends on the complete setup, including ECU calibration, fuel type, fueling system capacity, charge-air cooling, exhaust system, engine condition, boost target, dyno type and correction factor, supporting modifications, and installation quality.

An S55 running pump gas with conservative tuning will not produce the same output as a car running an ethanol blend, upgraded fueling, proper cooling, and a custom calibration. The 800+ HP rating should be understood as airflow potential. The turbochargers can support the airflow needed for that level, but the vehicle must be built properly around them.

 

Dyno / Validation Status

 

Dyno validation in progress. Our 2020 BMW M2 Competition test vehicle is targeting approximately 600 HP on pump gas and approximately 750 HP on E85. Verified dyno results, spool data, and [crank/wheel] figures will be published here as testing completes — [add expected timeframe]. Check back or [join the list] for the release.

 

Real-World Test Vehicle: 2020 BMW M2 Competition

 

To support development and validation of the TR S55 Twin Turbo Kit, we are testing the kit on a 2020 BMW M2 Competition equipped with the S55 engine and manual transmission. This test vehicle is being used to evaluate turbo response, fuel system demand, charge-air cooling performance, drivability, and real-world power potential on both pump fuel and E85.

 

Test Vehicle Hardware Configuration

 

This setup gives us a practical development platform for evaluating the turbo kit on a real street-driven S55 build. The vehicle is not a fully built race car — it still uses a stock S55 engine, stock cylinder head, stock clutch, stock airbox, and no methanol injection. That makes the test vehicle relevant to customers who want serious power without immediately building the entire engine.

 

Bend Calibration BMW F8x Ultimate Flex Fuel Kit

 

The test vehicle is equipped with the Bend Calibration BMW F8x Ultimate Flex Fuel Kit, an important part of the E85 development setup. According to Bend Calibration, the kit includes a flex sensor, CANBUS ethanol content analyzer, plug-and-play fuel lines, hoses, fittings, mounting bracketry, ID F750 fuel filter, fuel filter differential pressure indicator, and PNP harness. Bend also states the kit plugs into the stock BMW fuel lines and allows installation and removal back to stock condition, and that its flex fuel kits work with BM3 and Ecutek tuning programs.

For a high-output S55 running ethanol, this matters for two reasons. First, ethanol content needs to be accurately monitored — E85 is not always exactly 85% ethanol and can vary by station, season, and region, so a flex fuel system lets the calibration account for the actual ethanol content in the tank. Second, ethanol fuel system cleanliness matters: the Bend kit's ID F750 fuel filter and filter pressure indicator give the vehicle additional filtration support for ethanol use. Bend recommends replacing the filter element every 10,000 miles, or sooner if the indicator shows signs of fouling, depending on fuel quality.

Test Vehicle Power Goals

 

• Pump gas: approximately 600 HP
• E85: approximately 750 HP

 

On pump fuel, the goal is a strong but controlled power level that respects the limits of octane, intake air temperature, and engine safety. With E85, the goal increases because ethanol provides improved knock resistance and charge-cooling benefits. Combined with upgraded turbos, upgraded charge cooling, EU5 injectors, flex fuel monitoring, fuel filtration, HPFP support, and an upgraded crank hub, the S55 platform can be pushed significantly harder than on pump gas.

These numbers are test targets, not guaranteed results for every vehicle. Final output depends on fuel quality, tuning strategy, fuel pressure stability, cooling performance, drivetrain condition, and installation quality.

 

What This Test Setup Tells Us

 

The core performance upgrades are focused on the areas that matter most: TR upgraded twin turbos, catless exhaust flow, Armytrix midpipe and valved exhaust, upgraded charge-air cooling, flex fuel capability, Bend CANBUS ethanol content analyzer, Injector Dynamics ID F750 fuel filter, EU5 injectors, HPFP / lift kit support, and an upgraded crank hub. This creates a realistic foundation for a high-output street S55 build.

At the same time, the test vehicle also highlights where customers need to be realistic. A stock clutch, stock spark plugs, stock low-pressure fuel pump, and stock pre-throttle pressure sensor may become limiting factors depending on the final boost target, fuel type, torque output, and tuning strategy.

 

Recommended Supporting Mods for the TR S55 Twin Turbo Kit

 

A turbo upgrade should be planned as a full system, not a single part installation. The higher the horsepower target, the more important supporting modifications become.

 

Baseline Supporting Mods for Upgraded S55 Turbos

 

For any upgraded turbo S55 build, these should be considered the minimum foundation:

• Professional ECU calibration for upgraded turbos
• Reduced-restriction exhaust path
• Upgraded charge cooling system
• Proper spark plugs gapped for higher boost
• Boost leak inspection and pressure testing
• Fresh engine oil and coolant before installation
• Clean air filters and unrestricted intake path
• Verified fuel quality and fuel system health check
• Proper installation by an experienced BMW performance shop

 

Recommended Mods for 600–700 HP Builds

 

For customers targeting the 600–700 HP range, the setup should usually include:

• Custom ECU tune
• High-flow / reduced-restriction exhaust path
• Upgraded heat exchanger or charge cooling solution
• Upgraded intake system or high-flow drop-in filter
• Colder spark plugs properly gapped for boost
• Ethanol blend or higher-octane fuel strategy
• Fuel pressure monitoring
• DCT transmission tune for DCT vehicles
• Upgraded clutch for manual vehicles, depending on torque target
• Quality tires to manage the added power

At this level, fuel and temperature control become very important. The car may make strong dyno numbers, but repeated pulls, hot weather, or track use will expose weak cooling and fueling setups quickly.

 

Recommended Mods for 700–800+ HP Builds

 

For customers targeting 700–800+ HP, the build becomes much more serious:

• Full custom tuning
• Upgraded low-pressure fuel pump system, if fuel pressure demand requires it
• Supplemental fueling or port injection, depending on tuner strategy
• Ethanol content monitoring if using ethanol blend or E85
• Fuel filtration for ethanol use
• Upgraded charge cooling system
• High-flow intake and exhaust path
• Upgraded crank hub solution
• DCT tuning or upgraded clutch system
• Drivetrain inspection
• Upgraded tires
• Brake and suspension upgrades for safety
• Regular data logging and post-install inspection

At this level, the car should be treated as a complete performance system. The engine, fuel system, cooling system, transmission, tires, and brakes all need to match the power goal.

 

Crank Hub Consideration

 

The S55 crank hub is one of the most discussed weak points on the platform, especially on modified cars. For conservative setups, some owners choose to leave it alone. For aggressive boost, ethanol, track use, or 700+ HP goals, addressing the crank hub is a smart conversation to have before pushing the car hard.

Our test vehicle is equipped with an upgraded crank hub solution. For customers targeting aggressive boost, ethanol, repeated high-load driving, or 700+ HP, we strongly recommend addressing the S55 crank hub before pushing the vehicle hard. This is especially important on high-torque builds where engine timing security is critical.

 

Fueling Strategy: Pump Gas, Ethanol, or Race Fuel

 

Fuel choice has a major impact on final power.

Pump Gas. Suitable for conservative setups, but it limits boost, timing, and overall power potential. It is not the ideal fuel for chasing 800+ HP.

Ethanol Blend / E85. Ethanol blends can support more aggressive tuning because of their cooling effect and knock resistance. However, ethanol requires enough fuel system capacity and accurate ethanol content monitoring — the higher the ethanol content and power target, the more important the fuel system becomes. Even with flex fuel hardware, fuel filtration, EU5 injectors, and HPFP support, the LPFP may become a limiting factor depending on boost target, ethanol content, and final power level, so fuel pressure should be monitored carefully during tuning.

Race Fuel. Race fuel can support high-output tuning, but it should be used with a proper calibration designed for that fuel. Simply adding race fuel without tuning is not a complete strategy.

For customers serious about 700–800+ HP, the fuel system should be planned with the tuner before installation.

 

Cooling and Heat Management

 

High-output S55 builds generate more heat. More boost means more compressed air temperature, more exhaust heat, and more stress on the cooling system. Recommended cooling upgrades may include an upgraded heat exchanger, improved charge-air cooling, high-quality coolant, proper bleeding of the cooling system, oil cooling inspection, heat shielding where needed, and regular monitoring of intake air temperatures.

A car that makes one strong dyno pull but overheats after repeated driving is not a properly sorted build. Cooling should be part of the plan from the beginning.

 

Transmission and Drivetrain Considerations

 

More power also means more torque load on the drivetrain. For DCT cars, transmission software should be considered so the gearbox can manage higher torque output properly. For manual cars, clutch capacity becomes a major concern — a stock clutch may not hold the torque of a larger turbo setup, especially with ethanol or aggressive boost.

Depending on the power target and use case, supporting drivetrain upgrades may include a DCT transmission tune, an upgraded clutch for manual cars, differential and axle inspection, engine and transmission mounts, and tires matched to the power level. Power is useless if the drivetrain cannot apply it reliably.

 

Spark Plug Recommendation

 

The test vehicle currently uses stock spark plugs during development, but for customer builds running higher boost, colder spark plugs with the correct gap are recommended. Spark plug choice and gap should be matched to the tune, boost target, fuel type, and ignition system condition. Misfires under boost are common when plugs are worn, incorrectly gapped, or not matched to the power level.

 

LPFP and Fuel Pressure Monitoring

 

The test vehicle currently uses HPFP / lift kit support without an upgraded LPFP. Depending on the final E85 target and tuning strategy, the low-pressure fuel system may become a limiting factor. If fuel pressure drops at higher boost, higher rpm, or higher ethanol content, an LPFP upgrade may become necessary. For serious E85 builds, fuel pressure should be monitored during tuning and data logging.

 

Fuel Filter Maintenance for Ethanol Use

 

Ethanol builds should not ignore fuel filter maintenance. As noted above, the Bend F8x Ultimate Flex Fuel Kit includes an ID F750 fuel filter and differential pressure indicator, with Bend recommending replacement every 10,000 miles (or sooner if the indicator shows fouling). This is especially important on high-output S55 builds using upgraded injectors and ethanol fuel — a strong turbo setup is only as reliable as the fuel system supporting it.

 

Pre-Throttle Pressure Sensor Consideration

 

The test vehicle currently uses the stock pre-throttle pressure sensor. Depending on boost target and tuning strategy, a higher-range pressure sensor may be recommended. This should be determined by the tuner based on the final calibration and boost control requirements.

 

Installation and Tuning Recommendations

 

Turbocharger installation on the S55 platform should be handled by an experienced BMW performance shop. Proper installation matters because the turbo system depends on correct oil feed, coolant routing, gasket sealing, actuator setup (remember the actuator transfers from your stock turbos), and calibration.

Before installation, confirm: the engine code is S55 (not N55 or S58); supporting modifications match the target power level; the tuner is familiar with upgraded S55 turbo systems; oil and coolant lines are installed correctly; all gaskets and hardware are properly seated; the transferred actuators are functioning; and the car is inspected after initial heat cycles.

After installation, the vehicle should be professionally tuned and checked for boost leaks, fuel pressure stability, ignition timing behavior, knock activity, intake air temperature, wastegate and actuator function, oil and coolant leaks, air/fuel ratio, and transmission behavior.

Do not install upgraded turbos and drive aggressively without a proper calibration. That is how expensive engines fail.

 

Emissions and Legal Notice

 

Some supporting modifications, such as catless exhaust sections or OPF removal, may not be legal for street use in certain regions. Customers are responsible for ensuring their vehicle complies with all local, state, and federal emissions regulations. The TR S55 Twin Turbo Kit should be installed and used in accordance with applicable laws. Bend Calibration also lists the F8x Ultimate Flex Fuel Kit as for racing and off-road use only.

 

Who Is This Kit For?

 

The TR S55 Twin Turbo Kit is best suited for BMW owners who want more than a basic Stage 1 or Stage 2 setup. It is ideal for F80 M3 owners targeting serious street power, F82/F83 M4 owners building a high-output S55, F87 M2 Competition and M2 CS owners looking for a full turbo upgrade, enthusiasts seeking 700–800+ HP potential, builds using upgraded fueling and professional tuning, and drivers who want stronger top-end power without ignoring response.

This is not the right upgrade for someone who only wants a mild tune or simple bolt-on setup. It is designed for owners with a clear performance goal and the willingness to build the car properly around that goal.

 

Final Thoughts

 

The TR S55 Twin Turbo Kit is a serious upgrade for BMW F8X owners who want to push the S55 platform beyond factory turbo limitations. With ball bearing turbochargers, high-flow turbine design, matched manifold, intake pipes, oil and water lines, gaskets, and hardware, it provides a complete foundation for high-output builds.

Its 800+ HP capability makes it suitable for aggressive S55 projects, but the final result depends heavily on fuel, tuning, cooling, drivetrain preparation, and supporting modifications. Our 2020 BMW M2 Competition test vehicle shows how we are approaching the platform properly: upgraded turbos, upgraded crank hub, catless exhaust flow, upgraded charge cooling, EU5 injectors, HPFP support, Bend flex fuel hardware, ethanol content monitoring, fuel filtration, and professional calibration.

The honest truth is simple: the turbo kit provides the airflow potential, but the build quality determines the result.

 

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Ready to Build Your S55?

 

The TR S55 Twin Turbo Kit gives you the airflow foundation for a 700–800+ HP build. Pair it with proper fueling, cooling, and professional tuning, and the S55 platform delivers.

• Price: $4,995
• Availability: In stock
• Warranty: 12-month limited warranty
• Questions about fitment or your build plan? Send us a message.

Not sure if your car is S55? It must be an F80 M3, F82/F83 M4, F87 M2 Competition, or F87 M2 CS. The standard F87 M2 (N55) and G87 M2 (S58) are NOT compatible.

 

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FAQ

 

Does the TR S55 Twin Turbo Kit fit the standard F87 M2? No. The standard F87 M2 uses the N55 engine. This kit is designed only for S55-powered models.

Does it fit the F87 M2 Competition? Yes. The F87 M2 Competition uses the S55 engine, so it is included in the fitment list.

Does it fit the G87 M2? No. The G87 M2 uses the newer S58 engine and requires a different turbocharger system.

How much power can this kit support? The kit is designed for builds targeting 800+ HP, depending on fuel, tuning, cooling, engine condition, drivetrain setup, and supporting modifications.

What comes with the kit? Turbochargers, exhaust manifold, gaskets, oil pipe, water pipe, hardware kits, and front/rear turbo compressor intake pipes. An actuator is not included — the stock actuator transfers over from your factory turbochargers.

Is an actuator included? No. You reuse the factory actuator from your stock turbos. Inspect it for proper function during installation.

Is professional tuning required? Yes. Any upgraded turbocharger setup on the S55 requires professional ECU calibration. The turbo kit should not be installed and driven aggressively without proper tuning.

Do I need supporting mods to make 800+ HP? Yes. To reach the 800+ HP range, the vehicle will need proper fueling, tuning, cooling, exhaust flow, drivetrain preparation, and engine health. The turbo kit supports the airflow potential, but the rest of the build determines the final result.

Is a crank hub upgrade required? For mild builds, some owners may choose not to address it. For aggressive boost, ethanol, track use, or 700–800+ HP goals, a crank hub solution is strongly recommended. Our test vehicle is equipped with an upgraded crank hub solution.

Can this kit be installed on a stock car? Physically, upgraded turbos may be installed on a mostly stock vehicle, but that is not the right way to use this kit. For best results and reliability, the car should have proper supporting modifications and professional tuning.

What power is the TR test vehicle targeting? Our 2020 BMW M2 Competition test vehicle is targeting approximately 600 HP on pump gas and approximately 750 HP on E85, depending on final tuning, fuel quality, and validation results.

What flex fuel system is installed on the test vehicle? The Bend Calibration BMW F8x Ultimate Flex Fuel Kit, which includes a flex sensor, CANBUS ethanol content analyzer, plug-and-play fuel plumbing, ID F750 fuel filter, filter pressure indicator, and PNP harness.

Is the stock clutch enough? For lower power levels, the stock clutch may work depending on torque delivery and driving style. For aggressive ethanol tuning or 700+ HP goals, an upgraded clutch should be strongly considered on manual transmission cars.

Does the test vehicle have methanol injection? No. The current setup focuses on upgraded turbos, exhaust flow, charge cooling, EU5 injectors, HPFP support, Bend flex fuel hardware, fuel filtration, and E85 calibration.

 

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Build/Dev Notes (remove before publishing)

 

• Bracketed items still needing your input: crank vs. wheel HP rating; mounting confirmation (factory location, no cutting); supported tuning platforms for the turbo kit; whether boost control solenoids/BOV are needed; dyno timeframe; contact details.
• SEO to-dos: add FAQ schema + Product schema (price $4,995, availability in stock, brand Tomioka Racing, SKU TR-TW2008).
• Media: queue product photos, install shots, dyno/build video.
• Naming consistency: factory turbos are precisely the Mitsubishi TF035HL4W (some vendors call them TD03) — keep one term across the site.
• Internal links: anchor supporting-mods sections to your intercooler, charge pipe, and crank hub product pages.