CSF is the #1 cooling choice for BMW and particularly F8X M3/M4/M2 Competition owners. With an industry-leading reputation and overwhelming success as the cooling experts, CSF has added the final piece to the already popular F8X Cooling Suite.

Like the other cooling systems on the F8X, the factory auxiliary radiators 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 have pushed the limits of their S55, CSF saw the need and demand. The F8X platform is also almost a decade old with the newest examples being at least 5 years old. Over time the original coolers end up with damaged or clogged fins that greatly reduce their cooling capacity.

Please Note:  Sold individually. Will fit both left and right sides.

Design & Engineering

CSF designed the coolers to be a true “Drop-in Fit” for easy installation. 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.

Each CSF F8X Auxiliary Radiator can fit the left or right side. The fitting and plugs are swappable and can be easily setup for either side.

OEM vs CSF

Compared to the OEM F8X coolers, the CSF units are a significant upgrade. CSF eliminated the OE plastic mounting pod by incorporating it into the modular design that fits both sides. This design improvement increases the size of both the core and tanks. The extra space taken from the mounting pod allowed for a ~7% increase in Core Size and an ~10% increase in Tank Volume. With a larger 2-row 42mm core, cooling efficiency and capacity are drastically increased. The high efficiency core using CSF’s Exclusive B-Tube Technology maximizes airflow and heat dissipation. 100% All-Aluminum construction ensures the best performance and durability. The mounting pins and brackets are much stronger and more durable than the OE plastic pod mounting system. In addition, the black finish provides extra protection and offers a stealthy look behind the grilles of your F8X.

In addition, the CSF auxiliary radiators also feature 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.

Modular Design

CSF used a modular design so the auxiliary radiator can fit either side. There are several benefits to this type of design and offers several benefits. One of those benefits is for serious track applications. Having spare parts is always a great idea. Having one auxiliary radiator that fits both sides where you’d normally need one of each is a big cost and space saver. Getting an extra as backup is more cost/space efficient with the CSF units.

F8X S55 Cooling System

The F8X S55 cooling system is decently complex. Diagrams have been included for anyone who doesn’t understand how the whole system flows.

The cooling system consists of 6 to 7 heat exchangers depending on your transmission. Numbers below refer to the graphic above.

1. Auxiliary Radiator (Right Side) – Charge Air Cooling System
• CSF #8528 – High Performance Auxiliary Radiator
2. Radiator – Engine Cooling System
3. Front Mount Heat Exchanger – Charge Air Cooling System
• CSF #8075/8075V – High-Performance Front Mount Heat Exchanger
4. Charge Air Cooler – Charge Air Cooling System
• CSF #8082 – Dual-Pass Top Mount Charge-Air-Cooler
8. Auxiliary Radiator (Left Side) – Engine Cooling System
• CSF #8528 – High Performance Auxiliary Radiator
9. Oil Cooler
• CSF #8220 – High-Performance Engine Oil Cooler
10. DCT Transmission Cooler
• CSF #8081 – Dual-Pass Race-Spec DCT Transmission Cooler

Because each auxiliary radiator is used for a different system you can elect to replace one at a time. For those looking to further improve the Charge Air Cooling system replace the right side auxiliary radiator. Those looking to improve the engine cooling system should replace the left side.

Charge Air System (5 – right side auxiliary Radiator)

Engine Cooling System (1 – Left side auxiliary Radiator)

Installed Images

Perfect drop-in fit in the factory location. Note the mounting pins and bracket on the CSF #8258 are aluminum vs the OE plastic. This offers more stable mounting and durability.

To ensure the part(s) you have ordered fits your vehicle, we run a compatibility check prior to dispatch. We can do this either using your registration number(UK) or the last 7 digits of your VIN. Simply enter your car details prior to checkout. 

CSF-8258

Manufactured by

CSF Radiators

Warranty

CSF Lifetime warranty