Description
Description
CSF High Performance Radiator for MK3 Ford Focus ST
The MK3 Focus ST earned a strong following thanks to its sharp styling, responsive chassis, and capable 2.0 L EcoBoost engine. As these cars continue to be enjoyed on the street and pushed hard on track, cooling demand has increased. The CSF High Performance Radiator offers a major improvement in coolant temperature control, making it a valuable upgrade for both daily driven and modified Focus ST models.
Design and Engineering
CSF collaborated with EcoBoost specialists to develop a radiator capable of addressing the high coolant temperatures seen in tuned and track focused builds. The result is a premium cooling solution engineered for maximum efficiency, durability, and perfect fitment. Even lightly modified cars or those driven in hot climates can benefit from the improved thermal stability this radiator provides.
CSF vs OEM
The factory radiator uses plastic end tanks and a single row aluminum core, suitable for normal use but not ideal for heat intensive applications. The CSF unit replaces this with a full aluminum construction featuring a 31 mm high performance core. Increased thickness and fluid capacity allow the system to absorb and shed heat far more effectively.
CSF’s exclusive B Tube technology increases heat transfer by around 15 percent when compared with standard oval tubes. Multi louvered fins further enhance efficiency by maximizing airflow through the core. Combined with TIG welded aluminum tanks, the radiator offers increased strength, reliability, and long term durability.
Triple Pass Flow Advantage
The CSF radiator incorporates a triple pass flow design that routes coolant through the core three times before exiting. This configuration reduces outlet temperatures, minimizes hot spots, and ensures stable cooling under sustained load. The result is more consistent performance during spirited driving and track sessions.
Features and Benefits
Features and Benefits
- 31 mm ultra high performance single row core
- Triple pass flow design for improved heat dissipation
- Cooling tubes with CSF B Tube technology
- 6.5 mm tall multi louvered fins for maximum surface area
- CNC machined mounting pins and brackets
- OEM style inlet and outlet for factory fitment
- 100 percent TIG welded aluminum construction
- True plug and play installation with no modifications required
- Individually pressure and leak tested
- Two year limited warranty
Technical Specifications
Technical Specifications
CSF vs OEM Radiator Comparison
| Feature | CSF | OEM |
|---|---|---|
| Cooling tubes | 52 | 56 |
| Cooling fin rows | 53 | 57 |
| Core thickness | 31 mm | 27 mm |
| Fin height | 6.5 mm | 6.0 mm approx |
| Core material | Aluminum | Aluminum |
| Tank material | Aluminum | Plastic |
| Construction | 100 percent TIG welded | Crimp on gasket |





