F87 M2 (N55) / F3X 340i/440i / F2X M240i High-Performance Auxiliary Radiator

An industry-leading reputation and overwhelming success with BMW cooling has made CSF the #1 cooling choice for the F87 M2 (N55), F3X 340i/440i, and F2X M240i/M140i.

The new CSF Auxiliary Radiators are a great addition to the popular F87 (N55) & F3X/F2X Cooling Suites. Like the other cooling systems on these BMWs, the aux rads do a pretty good job in stock form. However, once you start adding a lot of power and pushing the car in aggressive driving conditions, the factory systems start to show its limitations. As more and more owners keep pushing the limits of their M2s and Gen 1 B58s, CSF is here to keep them cool.

Details:

Design & Engineering

CSF designed the coolers to be a true "Drop-in Fit" for easy installation fitting both left and right sides. Each cooler mounts in the factory location and uses the OEM quick connections. The High-Performance Auxiliary Radiators work in conjunction with the rest of the cooling system to reduce temperatures. They not only help keep temperatures in optimal ranges, but prolong the heat soak threshold. There's nothing worse than having your track session cut short because you need to do a cooldown lap.

OEM vs CSF

Compared to the OEM coolers, the CSF units are a significant upgrade. The TIG welded aluminum tanks are much larger than the OE plastic tanks offering superior strength and fluid volume. A larger 2-row 42mm core increases cooling efficiency and capacity. This high efficiency core uses CSF's Exclusive B-Tube Technology and latest 5mm fin technology, maximizing airflow and heat dissipation. These 5mm fins significantly increase the heat exchange surface area improving overall cooling efficiency and recovery while still maintaining good airflow.

With many motorsports teams and race enthusiasts now pushing over 700 horsepower, the B58 is seeing coolant temperatures well above normal. Once temperatures pass a safe limit the B58 will go into limp mode. Needless to say this can ruin a race, track session, or your overall driving fun in general. CSF is here to keep your B58 running at peak performance.

Construction

100% All-Aluminum construction ensures the best performance and durability. The integrated mounting frame is much stronger and more durable than the OE plastic pod mounting system. In addition, the black finish provides extra protection and corrosion resistance.

CSF auxiliary radiators offer even more durability with the integrated bolt on rock guards to keep the coolers safe. You've no doubt heard horror stories about OEM coolers getting punctured and spilling fluids all over the road or track. Now you can feel more confident that your cooling system is safer from road debris.

F87 M2 N55 Cooling System

The F87 M2 Competition uses the same cooling system as the F8X M3 and M4, the N55 version has a completely different setup. The diagram below shows how the system is laid out.

The Auxiliary Radiator completes the F87 M2 Cooling Suite offered by CSF.

Gen 1 B58 Cooling System

The Gen 1 B58 cooling system is decently complex. Diagrams have been included to show the details of how the whole system flows.

The Auxiliary Radiator completes the Gen 1 B58 Cooling Suite offered by CSF.

⚠ Fitment Notes

F3X 340i/440i and F2X M240i

Some F3X 340i/440i and F2X M240i/M140i trim levels did not come equipped with any Auxiliary Radiators. Be sure to check your VIN to see how many coolers your BMW came with before ordering.

There were three different Auxiliary Radiators available for the F3X 340i/440i and M240i/M140i. The CSF #8355 is made to be a drop-in fit replacement for the BMW 17-11-8-625-447. It can also replace the BMW 17-11-7-628-057 & 17-11-7-600-697 with the correct mounting bracket(s). Vehicles that did not come equipped with the BMW 17-11-8-625-447 from the factory may require minor trimming to the air ducting to fit correctly. Models equipped with the M Sport Package & M Sport Brakes should use the 17-11-8-625-447, however you should verify using your VIN with a dealership.

The Upper Brackets are the same for all 3 versions of the Auxiliary Radiators. The lower bracket part numbers are listed below. Please note, the frames (cradles) are not required as the CSF #8355 incorporates the frame (BMW 17-21-8-625-445) into the cooler design.

Lower Brackets for the 17-11-8-625-447

F87 M2 (N55)

Does NOT fit the F87 M2 Competition which uses the S55 Auxiliary Radiators (CSF #8258). The F87 M2 with the N55 uses a Single CSF #8355 Auxiliary radiator mounted on the Left Hand Side. The Right Hand Side uses the CSF #8104 Race-Spec Engine Oil Cooler.

Installed Images

Features:

• Sold Individually - most applications use 2 auxiliary radiators
• Multi-Fit - Fits Both Left & Right Side
• 2-Row - 42mm High-Performance Core Featuring CSF's Exclusive B-tube Technology
• New 5mm Tall Ultra Efficient Fins with a Multi-Louvered Design for Maximum Surface Area Contact
• Tank Volume and Core Size Increased
• 100% All-Aluminum TIG-Welded Construction
• OEM Style "Quick Connect" Inlet/Outlet
• True "Drop-in Fit" Requires No Modifications to Install
• Includes Detachable Rock Guard
• Individually Leak and Pressure Tested
• High-Performance Upgrade Suitable for Professional Racing, Street Performance, or OEM Replacement
• Satin Black Finish for OEM+ Look