This is the APR Ultracharger System. The APR Ultracharger System dramatically increases horsepower and torque, and maximizes the power potential of the 3.0 TFSI. It removes a massive pre-supercharger restriction, allowing uninterrupted airflow into the supercharger for up to an astonishing 542 HP with APR's Supercharger and Crank Pulleys. Stunning carbon fiber and smooth cast-aluminum adorn the system, creating a clean and simple install that looks just as powerful as it is. Finally, APR's innovative Ultracharger ECU Upgrade delivers a smooth and exciting driving experience, and it is included as a free upgrade to all who own an APR Stage II ECU Upgrade. The Restriction The factory throttle body is a massive power-robbing restriction. Its cross-sectional area is ~25% smaller than the supercharger's inlet, causing airflow to plummet at high supercharger speeds. It's responsible for losses as high as 33 HP! The Solution The APR Ultracharger Throttle Body is huge. Its cross-sectional area is ~28% larger than stock, and an additional 5% larger than the supercharger's inlet. It completely eliminates the throttle body as a point of restriction and allows for maximum airflow into the supercharger. The APR Ultracharger ECU Upgrade APR's incredible Ultracharger ECU Upgrade is why it all just works. It delivers an outstanding driving experience, packed with a smooth daily driving, thrilling wide open throttle acceleration, and unmatched performance. It's our most advanced 3.0 TFSI software to-date, and it's included as a free upgrade to all who own an APR Stage II ECU Upgrade.