IAG Performance Triple Pass Street Series 42mm Radiator 2008-2014 WRX / 2008-2021 STI

The IAG Street Series 42mm Triple-Pass Radiator is a high-performance all-aluminum radiator engineered for 2008–2014 Subaru WRX and 2008–2021 STI models (GV/GR/VA chassis). Designed to outperform the factory radiator, this lightweight upgrade is ideal for hard-driven vehicles and modified engines that generate additional heat. Its aluminum construction delivers improved heat dissipation and durability, helping maintain stable engine temperatures under demanding conditions.

This radiator features an advanced triple-pass design that routes coolant through the core three times using internal baffles in the end tanks. By keeping coolant in the radiator longer than a traditional single-pass OEM design, cooling efficiency is increased by approximately 10–20 percent on average. The result is more consistent thermal control during spirited driving, track use, or high-load situations.

Built entirely from aluminum, the IAG Triple-Pass Radiator offers excellent resistance to cracking, warping, and corrosion while maintaining rapid heat transfer. The 42mm core provides increased cooling capacity without excessive weight, and the radiator is manufactured in the USA to meet the demands of high-performance applications.

The radiator is designed to work with OEM cooling fans using factory mounting locations. The lower outlet remains in the stock position and reuses the factory lower hose, while the upper inlet is relocated and requires the included IAG 4-ply silicone upper radiator hose. A welded -6 AN male fitting is included for coolant expansion tank setups, along with a -6 AN cap for applications that do not require it.