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

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

Unless explicitly stated otherwise, all products sold by R44 Performance Limited are designated RACE ONLY and are solely for competition or off-road use limited to racing formally sanctioned by a recognized racing organization. Any other use, including recreational off-road use, may violate local, state, and Federal laws. R44 Performance Limited does not implicitly or explicitly confirm the legality of using any products it sells on public roads; that is entirely the responsibility of the consumer.

It is the responsibility of the customer to check with all federal, state local and environmental laws before ordering and installing a product. R44 Performance Limited is not responsible for any fees, fines or costs that a customer may incur as a result of failing to check with federal, state, local or environmental laws before ordering and installing a product.

We get a large number of custom orders and requests everyday, so as a result it is not always possible for us to keep every item in stock at all times in our warehouse. If you require the item urgently please contact our sales team here to check the stock before you make your purchase.

We totally understand if you're not certain a part will be compatible with your car, so we highly recommend contacting us here with your query. Our friendly sales team will then be in touch to confirm if this part is the correct part you are looking for.

All in stock products ship the same day if ordered before 2pm GMT

For out of stock items we will contact you with an estimated wait time if not otherwise specified above.

We offer worldwide shipping on all products. If upon receiving your product you wish to return; we offer a 30-day returns policy. For our in-depth returns information please follow the link. "R44 Returns Policy

All of our products come with a standard warranty of 1-3 years. This is dependant on the type of product however. For more details please see our warranty page here.