The BorgWarner Turbocharger K04 is a high-performance turbocharger for Audi S3/TT 1.8 5V engines. It features a high-flow compressor wheel and turbine wheel, a robust bearing system, and an integrated wastegate for improved boost control. The K04 is capable of producing up to 18 psi of boost and is designed to provide increased power and torque throughout the rev range. It is an ideal upgrade for Audi S3/TT 1.8 5V owners looking to gain more power and performance.