Description
CSF continues its dominance in BMW cooling solutions with the #1 choice for B58 and N55 engines: the High-Performance Auxiliary Radiators. Designed specifically for enthusiasts and tuners, these radiators provide superior cooling for aggressive driving and high-power applications.
Direct Fitment for BMW Vehicles:
- 2016-2018 BMW F87 M2 (N55) – Left Hand Side only, requires 1 radiator
- 2016-2019 BMW F3X 340i (including xDrive) – Check VIN, 1 or 2 radiators depending on M Sport Package & M Sport Brakes
- 2017-2020 BMW F3X 430i/440i (including xDrive) – Check VIN, 1 or 2 radiators depending on M Sport Package
- 2017-2021 BMW F2X M240i (including xDrive) – Check VIN, 1 or 2 radiators
- 2016-2019 BMW F2X M140i (including xDrive) – Check VIN, 1 or 2 radiators
Core Benefits:
- 2-row, 42mm high-performance core with CSF Exclusive B-Tube Technology
- New 5mm tall fins with multi-louvered design for maximum heat exchange
- Increased tank volume and core size for superior cooling capacity
- 100% all-aluminum TIG-welded construction for durability and strength
- OEM-style quick connect inlet/outlet for a true drop-in installation
- Includes detachable rock guard for added protection against debris
- Satin black finish for an OEM+ aesthetic
- Individually leak and pressure tested
- Suitable for professional racing, street performance, or OEM replacement
Engineering Advantages:
CSF auxiliary radiators offer a significant upgrade over OEM units. Compared to the stock coolers, CSF units feature a thicker 42mm 2-row core versus the OEM 27.5mm single-row core, increasing cooling efficiency. The CSF tanks are all-aluminum, TIG-welded, and far stronger than the OEM plastic tanks. The new 5mm fins maximize surface area for heat dissipation while maintaining excellent airflow. The integrated mounting frame is stronger than the OE plastic pods, and the detachable rock guards prevent road debris damage.
Compatibility & Notes:
- F3X 340i/440i and F2X M240i/M140i vehicles may have different factory auxiliary radiator setups. Verify using your VIN.
- CSF #8355 replaces BMW part 17-11-8-625-447 and, with proper mounting brackets, 17-11-7-628-057 or 17-11-7-600-697.
- Minor air duct trimming may be required on some vehicles not equipped with the factory 17-11-8-625-447.
- F87 M2 Competition uses S55 auxiliary radiators; CSF #8355 only fits the N55 version.
Construction & Performance:
CSF High-Performance Auxiliary Radiators are engineered to work with the full BMW F87 M2 and Gen 1 B58 cooling suites. These radiators reduce operating temperatures, prolong heat soak thresholds, and prevent limp mode during high-performance driving. They offer improved durability under extreme conditions, supporting high-horsepower builds above 700 HP while protecting your engine from overheating.
OEM vs CSF Upgrade Summary:
CSF units feature a thicker 42mm core (vs. 27.5mm OEM), 2-row design (vs. 1-row OEM), 5mm tall fins (same height as OEM), and all-aluminum TIG-welded tanks (vs. OEM plastic). This combination results in increased fluid volume, better heat dissipation, enhanced cooling recovery, and longer-lasting durability under aggressive driving or motorsport conditions.
CSF #8355 Auxiliary Radiators are backed by a 2-year limited warranty, making them a reliable upgrade for your BMW’s N55 or Gen 1 B58 engine.
