2022+ CSF FE1 Civic Si High-Performance Radiator

2022+ CSF FE1 Civic Si High-Performance Radiator



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The Civic Si has been the darling of the compact tuner market since the 1980s. The formula of a lightweight chassis and high revving powerful engine has influenced countless tuner cars over the decades. While the latest FE1 Civic Si isn’t as small or light the older models, it is still a ton of fun to drive.

Out of the box, the FE1 Civic Si along with its Acura sister car, the DE4 Integra, are both very capable vehicles. Powered by Honda’s 1.5L Turbo making 200hp, these small sedans have ample performance for those looking for a spicier daily driver. While the cars are capable of having some fun on the track and doing very spirited driving, hard track driving can quickly tax the limits of the factory equipment. This is especially true of modified and tuned examples where the engine is generating a lot more heat. That is why CSF is pleased to announce the new High-Performance All-Aluminum Radiator for the 2022+ FE1 Civic Si and DE4 Integra.

Design & Engineering

CSF has a long and successful track record with Honda cooling systems. This history includes making factory radiators for Honda Performance Development (HPD). Honda uses the CSF private label HPD Race Radiator for the FK8 Civic Type R TCR and recently took delivery of a new system CSF developed for the FL5. CSF used the information and experience from building this Race Radiator to design a High-Performance version for the new FL5 CTR and the FE1 Civic Si. Like the racing radiator, this new High-Performance version features CSF’s latest 5mm fin cooling technology. The new fin design increases the heat transfer area of the radiator by 20-25% over other larger fin designs.


The original OE radiator from Honda is a plastic tank with a single row aluminum core design. While this is generally accepted as good quality and durable, it is not the best option for high horsepower builds and hard driving. Turbo cars get hot, and the L15CA is no exception. Anything you can do to help keep temperatures in check will improve longevity of your motor and components.

Just like the HPD Race Radiator, the CSF FE1 Civic Si / DE4 Integra Radiator features the latest 5mm fin technology. The smaller fins significantly increase the heat exchange surface area improving overall cooling efficiency. A 33% larger 2-Row 42mm aluminum core increases the fluid capacity of the radiator, and improves the cores ability to dissipate heat. CSF’s Exclusive B-Tube Technology increases the heat transfer by approximately 15% over regular oval welded tubes. In addition, the super-efficient multi-louvered fins maximize airflow through the core for the best possible performance.

The TIG-Welded 100% All Aluminum construction increases the overall strength of the radiator. This improves durability and longevity so you can be confident it will hold up to hard driving conditions. The CSF radiator mounts in the factory location and requires no modifications or cutting.

Testing CSF vs OEM

Testing vs the OE Civic Si Radiator hasn’t been conducted at this time. However, CSF did test the FL5 Civic Type R Radiator (CSF #7221) which uses the same core as the FE1 Civic Si Radiator (CSF #7222). The factory CTR radiator is more efficient than the factory Civic Si radiator so improvements with the CSF Radiator should be much more significant.

The test compared the FL5 CTR Factory Radiator to the CSF Radiator on an FL5 tuned to 294 whp and equipped with an upgraded/larger Front Mount Intercooler. The larger front mount intercooler has been shown to raise engine coolant temperatures by ~7%. This is due to the airflow restriction over the radiator. Test results showed a decrease of 8°C engine coolant temperature with the CSF Radiator vs OEM. As you can see, a radiator upgrade will be very important to anyone running a larger intercooler. The upgraded radiator will also be beneficial to anyone tracking their car.

Important Notes:

  • 2-Row, 42mm Ultra-High-Performance Core
  • Cooling Tubes with CSF’s Exclusive B-Tube Technology
  • New 5mm Tall Ultra Efficient Fins with a Multi-Louvered Design for Maximum Surface Area Contact
  • CNC Machined Mounting Brackets and OEM Style Inlet/Outlet
  • 100% All Aluminum TIG-Welded Construction
  • 1.4 Bar High Pressure Radiator Cap with CSF logo
  • 1-Hour “Mirror Finish” Hand Polish
  • True Plug-and-Play “Drop-in Fit” Installation Requires Absolutely No Modifications
  • Individually Leak and Pressure Tested
  • 2-Year Limited Warranty
  • 2022+ FE1 Honda Civic Si
  • 2022+ FE1 Honda Civic Sedan 1.5L Turbo
  • 2022+ FL1 Honda Civic Hatchback 1.5L Turbo
  • 2023+ Honda Accord (11th Gen) 1.5L Turbo & 2.0L Hybrid
  • 2023+ DE4 Acura Integra
OEM Part Numbers:
  • Honda/Acura: 19010-64A-A01