Pushing M Power Further: The Engineering Behind Falcon’s S55 & S63 Hybrid Turbochargers
BMW Motorsport’s twin-turbo powerplants—specifically the S55 3.0-litre straight-six and the S63 4.4-litre V8—are celebrated as modern engineering triumphs. Found in weapons like the F87 M2 Competition, F80 M3, F82/F83 M4, and the F90 M5, these engines deliver ferocious performance straight from the factory floor.
However, when you push these high-revving platforms beyond standard flash software maps, you run straight into the physical limits of the OEM turbochargers. Pushing factory turbos beyond their designed efficiency window creates extreme exhaust backpressure, skyrockets intake air temperatures (IATs), and chokes top-end horsepower.
At Falcon Turbo Developments in Sheffield, we engineer direct drop-in hybrid turbo upgrades that solve these restrictions. Built using precision CNC machinery, upgraded heavy-duty bearing systems, and custom-designed wheel profiles, our hybrid builds deliver dramatic airflow gains without sacrificing the razor-sharp throttle response BMW M cars are famous for.
The S55 Platform: Unlocking 700 BHP on the M2C, M3 & M4
The S55B30 engine uses a twin-turbo layout with two compact, fast-spooling Mitsubishi Heavy Industries (MHI) turbochargers. While this layout provides instantaneous low-end punch, the stock compressor wheels and tight turbine housings quickly become a restrictive bottleneck when aiming for serious Stage 3 power numbers.
To break past this barrier, our Falcon S55 Hybrid Turbo Upgrade retains the original MHI casting footprint while completely re-engineering the internal core:
- Custom Billet Compressor Wheel (47mm Inlet): Carved from aircraft-grade forged aluminium, this wheel features an extended-tip geometry that pulls in a significantly higher mass of air while reducing rotational mass.
- 9-Blade High-Flow Turbine Wheel (46mm Outlet): To eliminate the severe exhaust backpressure that builds up in the S55 manifold at high RPM, the hot side is fitted with a free-flowing 9-blade turbine shaft that allows spent gases to escape cleanly.
- Heavy-Duty Bearing System: Upgraded internal thrust bearings ensure the assembly safely withstands continuous, high-boost operation without axial movement or oil film breakdown.
- Plug-and-Play Precision: Supplied with genuine OEM fully calibrated actuators, our S55 hybrids bolt straight up to factory downpipes, charge pipes, and oil lines with zero custom fabrication required.
Performance Capability: With proper supporting hardware and custom ECU calibration, Falcon S55 hybrids easily deliver 650 BHP on standard 99 RON pump fuel, with the potential to reach up to 700 BHP on ethanol blends or race fuel setups.
The S63 V8 Platform: Escalating the F90 M5 to 900 BHP
The F90 M5’s S63B44 4.4-litre V8 is a monster of an engine, utilising a “Hot V” configuration where twin-scroll Garrett turbochargers sit directly inside the engine valley. This layout yields incredibly short exhaust tracts and instant boost build up, but it subjects the turbochargers to intense, concentrated thermal stress.
The Falcon F90 M5 S63 Hybrid Upgrade expands airflow capacity while enhancing structural durability under heavy heat cycles:
- Enlarged Billet Compressor Wheel (51mm Inlet): CNC-machined into the re-profiled cold-side housing, this oversized wheel delivers the massive volume of pressurised air needed to satisfy a 4.4-litre V8 operating at high boost levels.
- D5 Ultra High-Flow Turbine Shaft (54mm Outlet): Designed specifically to optimise exhaust gas velocity out of the Hot V layout, the D5 wheel sharply lowers exhaust gas temperatures (EGTs) and exhaust manifold pressure.
- Garrett OEM Foundation: Built using genuine original Garrett core castings to guarantee structural integrity, long-term heat resistance, and precise factory actuator integration.
Performance Capability: The Falcon F90 M5 hybrid turbos unlock an incredible 850 to 900 BHP headroom on the S63 engine while preserving smooth daily drivability and immediate transient throttle response.
Technical Breakdown: S55 vs. S63 Falcon Hybrids
| Feature / Specification | BMW S55 Hybrid Upgrade | BMW S63 F90 M5 Hybrid Upgrade |
|---|---|---|
| Engine Application | S55B30 3.0L Twin-Turbo Straight-6 | S63B44 4.4L Twin-Turbo V8 |
| Compatible Models | F87 M2 Comp, F80 M3, F82/F83 M4 | F90 M5 & M5 Competition |
| Base Core Casting | Genuine MHI OEM Housings | Genuine Garrett OEM Housings |
| Inducer / Compressor Inlet | 47mm Forged Billet Wheel | 51mm Forged Billet Wheel |
| Exhaust Turbine Spec | 46mm 9-Blade High-Flow Shaft | 54mm D5 High-Flow Shaft |
| Actuator System | Genuine OEM Fully Calibrated | Genuine OEM Fully Calibrated |
| Max Power Potential | 700 BHP (650 BHP Pump Fuel) | 850 – 900 BHP |
| Fitment | 100% Direct Plug-and-Play | 100% Direct Plug-and-Play |
Why Choose a Hybrid Turbo Over a Full Frame Setup?
When chasing high power numbers, some builders consider retrofitting large, custom standalone “full frame” turbos. While full-frame kits can achieve high peak figures on a dyno, they introduce massive compromises on modern BMW M platforms:
- Zero Fabrication Nightmare: Hybrid turbos utilise the factory housing footprints. They retain the stock oil feeds, coolant lines, intake pipework, and downpipe flanges, keeping installation straightforward and reducing labour hours significantly.
- OEM+ Engine Bay Aesthetics: Under the bonnet, everything looks entirely stock. This clean, factory appearance keeps your build looking professional and uncluttered.
- Flawless ECU Calibration: Factory electronic wastegates (EWGs) are seamlessly retained. This avoids the need for external wastegate controllers, keeping the factory Bosch ECU software in complete control over boost target strategies.
- Superior Transient Response: Because hybrid turbos optimise wheel weight using billet aerodynamics, they spool rapidly. You avoid the severe lag associated with large standalone turbos, preserving the instant mid-range punch required for fast-road driving or exiting tight corners on track.
Read more about the pros and cons when choosing between a Falcon Turbos hybrid turbo or a Full Frame turbo
The Falcon Standard: High-Speed VSR Dynamic Balancing
A hybrid turbo is only as good as its balance. At speeds exceeding 200,000 RPM, even a microscopic weight variance across the rotating assembly creates destructive centrifugal forces that destroy journal bearings and oil seals.
At our dedicated workshop in Sheffield, every single Falcon hybrid unit undergoes rigorous multi-stage testing on our in-house VSR Vibration Sorting Rig.
We simulate live engine conditions by running pressurised hot oil through the centre housing while spinning the core up to full operational RPM. Microscopic amounts of material are fine-tuned off the assembly until vibration harmonics drop to zero—significantly tighter than OEM factory tolerances. This guarantees whisper-quiet operation, rapid spooling, and long-term durability under high boost.
Essential Supporting Mods for Stage 3 M Builds
To extract maximum performance safely from your Falcon Hybrid upgrade, ensure your build includes these key supporting components:
- High-Flow Downpipes: Replacing restrictive factory catalytic converters with high-flow sports cats or decat downpipes lowers backpressure further, allowing the enlarged turbine wheels to spool up even faster.
- Upgraded Charge Cooling: High boost pressure increases charge air heat. Upgrading the charge-air cooler radiators on both the S55 and S63 keeps intake temperatures cool and ignition timing stable.
- Fuelling System Upgrades: Hitting 700+ BHP on the S55 or 850+ BHP on the S63 requires adequate fuel delivery. Upgraded high-pressure fuel pumps (HPFP) or port injection kits are required to support high-flow fuels or ethanol blends.
- S55 Crank Hub Protection: On high-output S55 builds, securing the engine’s crank hub with a keyed or capture solution is highly recommended to prevent timing slip under heavy torque loads.
- TCU Transmission Remapping: Whether running the M-DCT or the ZF 8-speed automatic, custom transmission software (raising torque limits and increasing clutch clamping pressure) is necessary to transmit the surge of power to the rear wheels cleanly.
Whether you are seeking 700 BHP for your M2 Competition, M3, or M4, or aiming to push your F90 M5 toward the 900 BHP mark, Falcon Turbo Developments provides engineered hybrid upgrades crafted right here in South Yorkshire. Contact our technical team today to discuss turbo specs, core exchange options, or custom tuning paths for your M car build.
