CSF Audi B5 A4 1.8T High-Performance All-Aluminum Radiator

With over five decades of expertise in radiator manufacturing, CSF stands as a leader in delivering superior cooling solutions. The CSF Audi B5 A4 1.8T High-Performance All-Aluminum Radiator exemplifies this commitment, engineered to maintain optimal engine temperatures and enhance the performance of your B5 A4 1.8T. Whether for daily driving or competitive motorsports, this radiator is meticulously designed to meet the rigorous demands of high horsepower applications and race environments requiring exceptional cooling capacity.

This radiator incorporates a 2-Row core featuring CSF's proprietary B-Tube Technology. Unlike conventional oval “O” type tubes, the innovative “B” shaped tubes are precision-formed and seam-brazed to achieve superior strength and durability. This advanced design allows the use of thinner, lighter aluminum material without compromising structural integrity, resulting in improved cooling efficiency. The unique inlet positioned in the middle of the brazed seam increases the heat transfer surface area by approximately 15% compared to standard tubes, effectively delivering the cooling performance of two smaller tubes within the same spatial constraints.

Additionally, the “B-tubes” facilitate dual liquid laminar flow, optimizing coolant movement through the radiator. Complementing this design, CSF employs ultra-efficient multi-louvered fins that are precisely aligned to maximize airflow across the radiator core. Each fin’s dimensions and orientation are carefully calculated and validated through extensive wind-tunnel testing to ensure maximum heat rejection efficiency, providing reliable cooling under demanding conditions.

The CSF B5 A4 1.8T radiator is engineered as a true “Drop-in fit” replacement, requiring no modifications for installation. All mounting brackets are CNC machined and welded to OE specifications, ensuring exceptional durability and precise fitment. The inlet and outlet connections are designed to match OEM configurations, allowing seamless integration with existing hoses—whether OEM or aftermarket—simplifying the upgrade process.

Features

• 2-Row, 42mm Ultra-High-Performance Dual Pass Core for enhanced cooling capacity
• 45 Cooling Tubes utilizing CSF's exclusive B-Tube Technology for superior heat transfer
• 6.5mm Tall Ultra Efficient Fins with Multi-Louvered Design to maximize surface area contact and airflow
• CNC Machined Mounting Brackets and OEM Style Inlet/Outlet connections for precise fit and durability
• Constructed from 100% All Aluminum with TIG-Welded joints ensuring strength and corrosion resistance
• Finished with a Smooth Satin coating for added protection and aesthetic appeal
• True Plug-and-Play “Drop-in Fit” installation requiring absolutely no modifications
• Designed exclusively for Manual Transmission applications
• Each unit is individually Leak and Pressure Tested to guarantee reliability
• Backed by a 2-Year Limited Warranty for peace of mind

Applications

OEM Part Numbers

• Audi: 8D0 121 251 P
• Audi: 8D0-121-251-P
• Audi: 8D0121251P

Warranty

Cooling Systems and Flexibles, Inc. (CSF) guarantees the quality and performance of its High-Performance Cooling Systems under normal use and service to the original purchaser of the vehicle in which the product was originally installed. For comprehensive warranty details, please visit our Warranty Page.

SKU# 7204 Warranty Term: 2 years

In summary, the CSF Audi B5 A4 1.8T High-Performance All-Aluminum Radiator represents a pinnacle of engineering excellence, combining innovative design with precision manufacturing to deliver reliable, efficient cooling. Its robust construction, advanced B-Tube Technology, and meticulous testing ensure that your vehicle maintains optimal operating temperatures under all conditions, safeguarding engine performance and longevity. Trust CSF to provide a high-quality, durable radiator that meets the exacting standards of both enthusiasts and professional racers alike.

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.