Koyo's aluminum radiators for the 2003-2007 WRX/STI are designed to keep your engine cool even under some of the harshest conditions. Koyo radiators are made from light weight aluminum and are made for street and track use.
Koyo is Japans largest aftermarket radiator manufacturer, utilizing the latest aircraft quality aluminum and Heli-arc welded. Heli-arc soldering is the highest quality standard for enforcement along aluminum connections. The Koyo radiator is roughly 20mm thicker then stock, allowing for larger capacity, better flow, and faster heat loss over the surface of the core.
Koyo uses a fin and tube pitch which significantly increases its surface area while still allowing for excellent air circulation through the radiator. All of their racing radiators are Nocolok brazed and are made as a direct bolt in with no engine modifications necessary. They retain mounts for the stock fan shrouds and fans as well.
Subaru WRX/STI 2003-2007 Manual Transmission