CSF Audi Classic and Small Chassis 5-Cylinder High-Performance All Aluminum Radiator

CSF uses a specially engineered tube in the shape of a "B" for their radiators, which increases the heat transfer surface area by about 15% over standard tubes. This design allows for a dual liquid laminar flow, making it more efficient than typical oval-shaped radiator tubes. This radiator is built for classic and small chassis Audi 5-cylinder models, including the Quattro, 4000, 80, and 90 series, and is designed to keep your engine running cool whether you're on the street or the track.

This all-aluminum radiator features a 2-row, 42mm dual-pass core with ultra-efficient, multi-louvered fins that are precisely aligned to maximize airflow and heat rejection. The B-tube technology is stronger than standard tubes, allowing CSF to use thinner, lighter aluminum without sacrificing durability. The OE-style mounting brackets are CNC machined for a solid, durable fit, and the inlet and outlet connections are designed to match the factory specifications, so you can reuse your original hoses. It's a true drop-in fit, meaning no modifications are needed for installation.

This radiator also includes multiple fan shroud mounting points, accommodating various fan setups including the high-performance RS2 model. It has multiple overflow pipe locations for different model variations and sensor ports that are M22x1.5 (note: an adapter may be needed for early M20x1.5 OEM sensors). This CSF radiator is individually leak and pressure tested to ensure reliability and comes with a 2-year limited warranty.