EJ DOHC Cylinder 4 Chamber Cooling System

The GDT Cylinder 4 Chamber Cooling System is the industry's first kit specifically designed to enhance coolant flow within the left-hand cylinder head of Subaru DOHC EJ engines. By increasing coolant circulation, this system effectively mitigates detonation-causing hot spots, leading to improved engine reliability and performance. The kit features a custom-formed NBR hose and a precisely machined, anodized 6061 fitting, ensuring durability and optimal performance. Complementing these components are an aluminum "T" fitting and four 304SS embossed worm clamps for secure installation. The system is engineered to directly address the known issue of uneven cooling in the cylinder 4 area on EJ20 and EJ25 engines. This cooling system is compatible with a range of Subaru models, including the 2002-2014 WRX, 2004-2021 STI, 2004-2008 Forester XT, and 2005-2009 Legacy GT. Installation is designed to be straightforward, with included instructions to guide the process, which typically takes approximately 2 hours and may require lifting the vehicle and draining coolant.