Mercedes-AMG GT Stage 3 Race Turbo Upgrade — C190 M178 4.0L Twin-Turbo V8
The YPG Motorsport Stage 3 Race Turbo upgrade for the Mercedes-AMG GT family (C190) replaces the factory turbocharger internals on the M178 engine with higher-flowing billet compressor wheels, upgraded Inconel turbine wheels, and uprated bearing assemblies — delivering 900+ WHP depending on supporting modifications and ECU calibration.
The M178 is the high-performance variant of Mercedes-AMG's 4.0L twin-turbo V8 — featuring a flat-plane crankshaft, dry-sump oiling, and a higher 8,000 RPM redline compared to the M177's cross-plane design. The factory turbochargers are conservatively sized, running out of airflow by 700–750 HP. The Stage 3 Race Turbo upgrade extends the turbo's breathing capacity while maintaining the factory housing dimensions, mounting points, oil and coolant line routing, and wastegate actuators. Bolt-on installation, no fabrication, no cutting, no permanent modifications.
What's Included
- 2x Stage 3 Race Turbochargers — complete drop-in units matched to the M178 dry-sump architecture
- Billet compressor wheels — CNC-machined from forged 2618 aluminium, optimised blade geometry for maximum airflow. The M178's higher redline demands a compressor wheel that flows efficiently across a wider RPM band than the M177 — these are spec'd accordingly
- Upgraded turbine wheels — high-temperature Inconel alloy, revised blade profile for improved exhaust gas flow at elevated boost pressures
- Ceramic-coated housings — thermal barrier coating on the turbine housings to reduce underhood heat soak. The AMG GT's mid-front engine placement and enclosed engine bay make thermal management critical — especially in GCC ambient temperatures exceeding 45°C
- Upgraded bearings and shaft assembly — uprated for sustained high-RPM, high-boost operation. VSR high-speed balanced as complete rotating assemblies
- New gaskets and hardware — everything needed for installation
Power Targets by Configuration
| Configuration | Estimated Output | Supporting Mods Required |
|---|---|---|
| Stage 3 Race Turbos + ECU Tune (pump fuel) | 850–900 WHP | Downpipes, tune, plugs |
| Stage 3 Race Turbos + Full Supporting Mods | 900–1,000+ WHP | Downpipes, intakes, intercooler, tune, fuel upgrades |
| Stage 3 Race Turbos + Forged Internals + E85 | 1,000–1,200 WHP | Full build — forged bottom end, E85, upgraded fuel system |
The M178's flat-plane crankshaft and dry-sump oiling give it inherent advantages over the M177 at high RPM — exhaust pulse separation is cleaner, oil starvation under sustained lateral G is eliminated, and the engine breathes more efficiently above 6,500 RPM. This translates to higher peak power from the same Stage 3 turbo hardware compared to M177-equipped vehicles.
Vehicle Fitment
| Model | Chassis | Years | Engine | Factory HP |
|---|---|---|---|---|
| Mercedes-AMG GT | C190 | 2015–2021 | M178 4.0T V8 | 462 HP |
| Mercedes-AMG GT S | C190 | 2015–2021 | M178 4.0T V8 | 510 HP |
| Mercedes-AMG GT C | C190 | 2017–2021 | M178 4.0T V8 | 550 HP |
| Mercedes-AMG GT R | C190 | 2017–2021 | M178 4.0T V8 | 577 HP |
| Mercedes-AMG GT R Pro | C190 | 2019–2021 | M178 4.0T V8 | 577 HP |
| Mercedes-AMG GT Black Series | C190 | 2020–2022 | M178 4.0T V8 | 720 HP |
Required Supporting Modifications
- Catless downpipes — mandatory for full power extraction. The factory catalytic converters create excessive backpressure that limits turbine efficiency. YPG catless race downpipes for the AMG GT are available separately
- Stage 3 ECU calibration — remaps boost targets, fuelling, ignition timing, torque limiters, and wastegate duty cycles specifically for this turbo hardware. The M178 ECU requires platform-specific calibration — M177 tunes do not apply
- Upgraded spark plugs — colder heat range plugs to prevent pre-ignition under higher cylinder pressures
- Upgraded intercooler — strongly recommended above 900 WHP. The AMG GT's engine bay runs hotter than sedan platforms due to the mid-front layout
- High-flow air filters or upgraded intakes — the compressor inlet is the next restriction after turbos and downpipes
- Forged internals — recommended above 950 WHP for sustained use. YPG Motorsport offers complete M178 crate engine builds rated to 1,500 HP
M178 vs M177 — Why the M178 Makes More Power
The M178 is not just an M177 in a different car. The flat-plane crankshaft fires cylinders in an alternating left-right sequence that produces cleaner exhaust pulses for the turbochargers — each turbine receives evenly-spaced exhaust events rather than the uneven firing order of the M177's cross-plane crank. Combined with the dry-sump oiling system (no oil pan to interfere with airflow or ground clearance), the M178 is inherently better suited to sustained high-RPM, high-boost operation. The same Stage 3 turbo hardware produces approximately 100 WHP more on the M178 than on the M177.
Installation
Bolt-on replacement using factory mounting points. The AMG GT's hot-V layout provides good turbo access once the intake manifold and charge pipes are removed. No fabrication, cutting, or permanent modifications required. Factory oil feed/drain lines, coolant lines, and wastegate actuators are retained.
Estimated installation time: 10–14 hours at a competent independent shop familiar with the AMG GT platform.
No core exchange required. You keep your factory turbochargers.
Warranty & Shipping
1-year warranty on all turbocharger components against manufacturing defects. Free worldwide shipping. GCC delivery via FedEx International Priority in 1–3 business days. International shipping typically 5–10 business days. Ships from Kuwait.
Contact YPG Motorsport for lead times and availability: sales@ypgmotorsport.com or WhatsApp us directly.