Stage II Turbo Upgrade Package

The RENNtech Stage II Turbo Upgrade Package is a comprehensive performance enhancement specifically designed for the Mercedes X290 GT 63 (S) AMG 4-Door Coupe equipped with the 4.0L V8 BiTurbo M177 engine, model years 2019 and newer. This package includes upgraded turbos, an ECU upgrade, an upgraded CPC Unit, and a Fuel System Upgrade to unlock substantial power gains. The core of this upgrade lies in RENNtech's lightweight forged billet turbo wheels, which feature a larger impeller on the inlet side and an increased turbine trim on the exhaust side. The supporting cartridge shaft is both larger and stronger, and the entire assembly is precisely balanced for safe operation at higher power levels. The impeller and turbine housings are CNC machined and flow tested in-house to accommodate the larger internal cartridge. With this Stage II Turbo Upgrade, the vehicle can achieve up to 1,017 horsepower and 873 lb-ft of torque at the crank when using 100 Octane Fuel. This represents peak gains of up to +336 HP and +137 LB-FT over stock. The package also offers quicker spooling, a more responsive throttle, and immediate power delivery due to reduced exhaust back pressure, lower rolling resistance, and lighter rotating mass. To reach the full power output level, RENNtech Downpipes, an Air Filter, and BOV Adapters are required. The product notes that baseline M177 engine performance numbers can vary, and RENNtech's gains are calculated based on their own dyno measurements. Power calculations for 4MATIC+ vehicles assume a 16% drivetrain loss. It is mandatory to use 93+ Octane gasoline with this performance upgrade; states with poor fuel quality may require a lower power setup.