Koyorad Aluminum Radiator KH082661 2012-2015 Honda Civic Si

Koyorad Aluminum Racing Radiator KH082661 for 2012-2015 Honda Civic Si

If you're tracking or hard-driving a 9th gen Civic Si, the factory plastic-tank radiator is the weak link in your cooling system. Those OEM end tanks crack with age and heat cycling, and the core just doesn't have the capacity to hold temps during sustained high-load running. This Koyorad all-aluminum radiator (part number KH082661) is the direct upgrade for the 2012-2015 Civic Si: a thicker, higher-capacity core in a fully welded aluminum housing that bolts right into the factory location.

The core is Koyo's 25mm Hyper Core, about a 50% increase in thickness over the stock radiator, which means substantially more coolant volume and more surface area to pull heat out. That extra capacity is what keeps your K24Z7 in its happy temperature range during back-to-back pulls or a full track session instead of slowly climbing toward trouble. It's all-aluminum and TIG-welded by hand, so you also lose the failure-prone plastic end tanks that eventually let go on these cars.

Direct bolt-in fitment for the 2012-2015 Civic Si

Koyorad built this radiator to OEM dimensions, so it's a true direct replacement on the 2012, 2013, 2014, and 2015 Civic Si. It reuses your factory fans, fan shroud, radiator hoses, and AC condenser with no cutting, drilling, or fabrication. Drain the coolant, pull the stock radiator, and drop the Koyo unit into the same mounts. The filler neck and drain plug are CNC-machined aluminum, and the finish is clean enough to look at home in a dressed-up bay.

One important thing before you install: this radiator is not compatible with the factory radiator cap. You need a Koyo SK-C13 cap (or equivalent), sold separately, to seal and pressurize the system correctly. Add one to your order so you're not stuck mid-install. Fitment is 2012-2015 Civic Si coupe and sedan with the manual transmission, so confirm your car before ordering.