CSF Racing

The best CSF Racing product here for a WRX or STI owner is its only entry: the CSF 2-Row Subaru Aluminum Radiator, B22415-RS, titled for 2008-2021 WRX/STI. Dealer listings for this part describe an all-aluminum, 2-row core built to replace the factory radiator and improve cooling efficiency. Start here if yours is aging, leaking at its plastic end tanks, or struggling on track days.

A radiator sheds the heat coolant collects from the engine, and capacity matters once a turbo Subaru works hard. An all-aluminum 2-row core gives more surface area than the factory unit, and removes the plastic end tanks that grow brittle with heat cycles. Dealer listings also name CSF B-Tube core technology and a radiator cap included. Browse Cooling and Radiators ranges alongside it, and read cooling solutions for turbocharged WRX for the intercooler side of the heat problem.

Brands to know

CSF Racing is the race-facing shelf of CSF in this store, and this radiator shows the formula: all-aluminum construction, a 2-row core and B-Tube technology, described in dealer listings as a stronger tube shape with more heat-transfer surface. The main CSF collection carries the broader cooling range for owners comparing sizes and finishes. Judge CSF on cooling depth; radiators and intercooler cores are its whole business here.

COBB Tuning is the name attached to this radiator in dealer listings, which sell it as a COBB CSF unit, and its shelf here is the Subaru tuning ecosystem: Accessport engine management plus intakes, exhausts and supporting hardware for WRX and STI. That pairing matters because cooling upgrades usually arrive alongside power upgrades. A radiator bought with a tune in mind should be sized for the finished build, not the stock car.

Mishimoto is the other large cooling range in this store, carried for radiators, intercoolers, hoses and fans across Subaru and other platforms. It is the natural comparison shelf for a CSF buyer weighing core size, finish and price. Read each listing's fitment years carefully, as Subaru radiator fitments split by generation and transmission.

Koyo Cooling covers radiators and radiator caps in this store, including a radiator titled for 2008-2021 WRX and STI in its listings. Koyo is the cross-shop for owners who want a Japanese cooling brand with a long Subaru fitment list. Whichever brand you choose, plan fresh coolant and a careful bleed of the system as part of the job.

FAQ

Which cars does this CSF radiator fit?

The title states 2008-2021 WRX and 2008-2021 STI. That span covers two generations, so check your year, model and transmission fitment against the listing before ordering.

Why replace a factory radiator that still works?

Factory radiators use plastic end tanks that weaken with heat cycles, and a leak can overheat an engine quickly. An all-aluminum unit removes those tanks and adds capacity, suiting tuned, tracked or high-mileage cars.

Is a tune required after fitting it?

No. A radiator changes neither airflow nor fueling, so it does not by itself call for a tune. It supports tuned cars by keeping temperatures steadier under load.

How involved is installation?

Expect a drain, swap and refill: hoses, fans and shrouds move over, the system is refilled and bled, and leaks are checked at full temperature. Allow a half day and fresh coolant rather than rushing it.