CSF Audi B5 S4 High-Performance All-Aluminum Radiator

With over five decades of expertise in radiator manufacturing, CSF stands as a leader in delivering advanced cooling solutions. The CSF Audi B5 S4 High-Performance All-Aluminum Radiator is engineered to maintain optimal engine temperatures, ensuring your B5 S4 operates at peak efficiency under all conditions. Whether on the street or the track, this radiator is an essential upgrade for vehicles requiring enhanced cooling capabilities, particularly for high horsepower builds and motorsport applications. At the core of this radiator’s superior performance is CSF’s exclusive B-Tube Technology. Unlike conventional oval-shaped “O” type tubes, the B-Tubes are uniquely shaped and seam-brazed to provide exceptional strength and durability. This innovative design allows the use of thinner, lighter aluminum material without compromising structural integrity, resulting in improved heat dissipation. The B-Tube’s inlet positioned centrally within the tube increases the heat transfer surface area by approximately 15% compared to standard tubes. This effectively delivers the cooling efficiency of two smaller tubes within the same spatial constraints, facilitating dual liquid laminar flow for enhanced thermal management. Complementing the B-Tube design, the radiator incorporates ultra-efficient multi-louvered fins that are meticulously aligned to maximize airflow through the core. Each fin’s dimensions and placement are carefully calculated and rigorously tested in CSF’s wind tunnel laboratory to ensure optimal heat rejection performance. This attention to detail guarantees that the radiator can handle demanding cooling requirements while maintaining reliability and durability. The CSF B5 S4 radiator is designed as a true “Drop-in fit” replacement, requiring no modifications during installation. All mounting brackets are precision CNC machined and welded to meet stringent durability standards. The inlet and outlet connections are engineered to match the original equipment manufacturer (OEM) specifications, allowing seamless integration with existing OEM or aftermarket hoses. This ensures a straightforward installation process and compatibility with all original components, including the AC condenser, mounting brackets, and fan shroud. Features 2-Row 42mm Core (Dual Core) Featuring CSF’s Exclusive B-Tube Technology for Enhanced Cooling Efficiency Core Equipped with Ultra-Efficient Multi-Louvered Fins with 6.5mm Fin Height to Maximize Surface Area Contact and Airflow CNC Machined “Quick-Connect” Inlet and Outlet Connections for Precise Fit and Reliable Sealing CNC Machined Brackets and Fittings Engineered for Superior Durability and Perfect Alignment All-Aluminum Race Style Drain Plug for Convenient Maintenance and Longevity Smooth Satin Finish Providing Corrosion Resistance and Aesthetic Appeal “Drop-in Fit” Design Eliminates the Need for Modifications, Compatible with OEM Components Including Quick Connect Hoses, AC Condenser, Mounting Brackets, and Fan Shroud Applications Year Range Make Chassis Code Model Trim Engine / Trans / Etc Notes 2000-2002 Audi B5 S4 – Turbocharged 2.7L V6 (Manual) – OEM Part Numbers Audi: 8D0 121 251 AP Audi: 8D0-121-251-AP Audi: 8D0121251AP Audi: 8D0 121 251 AP VAG Audi: 8D0-121-251-AP-VAG Audi: 8D0121251APVAG Warranty Cooling Systems and Flexibles, Inc. (CSF) guarantees its High-Performance Cooling Systems under normal use and service to the original purchaser of the vehicle in which the product was installed. This warranty reflects CSF’s commitment to quality and reliability. For comprehensive warranty details, please visit our Warranty Page. SKU# 7071 Warranty Term: 2 years