WGA Internal Wastegate Actuator

The GFB 7305 WGA is a high-performance, bolt-on internal wastegate actuator engineered to enhance boost control for turbocharged Subaru WRX STI models from MY99-21. This actuator aims to increase the "area under the boost curve" by bringing boost on sooner and holding it longer. Its larger diaphragm provides greater control authority over the wastegate flap, preventing exhaust backpressure from forcing it open during critical spool-up and high RPM phases, a common issue with factory actuators, especially in Subaru's 2-port boost control system. Constructed with an industry-first Nomex-reinforced silicone diaphragm for optimal area within a compact diameter, the WGA also boasts a short height and a 18mm long stroke for extensive adjustment without necessarily changing springs. The actuator's body is CNC machined from billet 6061 aluminum, and it features a unique pivoting rod guide made from PEEK for low friction and superior wear resistance. The unit is supplied with three stainless steel springs (5psi, 10psi, 7psi) that can be combined to achieve boost pressures ranging from 5psi to 22psi. A key innovation is the turnbuckle pre-load adjustment, allowing for fine-tuning of base boost pressure in minutes without removing the actuator. While the WGA is a bolt-on product, it is considered a tuning tool as it WILL increase boost pressure. Therefore, TUNING IS REQUIRED after installation. This wastegate actuator is designed for Subaru WRX STi models from MY99-21 and also fits most single-scroll IHI VF turbos.