GFB WGA Internal Wastegate Actuator African american adult female Generated.photos. The WGA is a high performance bolt on internal wastegate actuator designed to bring boost on sooner and hold it longer! The WGA is all about increasing the area under the boost curve. With a larger diaphragm than the OEM actuator, the WGA has more control authority over the wastegate flap. This makes it harder for exhaust backpressure to blow the wastegate open during spool up and at high RPM, two areas of the boost curve where the factory actuator can be overwhelmed. This benefit is particularly useful with Subarus factory 2 port boost control system, which cannot effectively shut off pressure to the wastegate during spool up. Supplied with 3 springs and a unique turnbuckle pre load adjustment, the base boost pressure can be configured and adjusted from 5psi to 24psi for the best possible boost control. Read on for more technical information on wastegate springs, and how the correct spring selection can improve performance. The WGA features a longer stroke, shorter height, and more adjustment than its rivals. WGA part # 7305 is designed to bolt on to Subaru WRX STI models from MY99 21 and will also fit most single scroll IHI VF turbos. The 5psi and 10psi springs are installed for a base pressure of 15psi, and the 7psi spring is included in the packaging for further tuning options. MORE ADJUSTABLE, MORE EASILY. Setting the base spring pressure correctly for your application can have significant performance benefits, so we made sure the WGA offers the best adjustability on the market! We supply 3 stainless steel springs that can be used in any combination ranging from 5psi to 22psi, but thats only the beginning. Whilst other brands may offer more spring options (sold separately), changing springs to fine tune boost pressure is time consuming and quite frankly, a pain in the butt. Thats why we added another industry first: turnbuckle adjustment. Because the WGA was designed with a long stroke, it is possible to use some of that extra stroke length to fine tune the base boost pressure in a matter of minutes without swapping springs or removing the actuator. As an added benefit, the turnbuckle makes swapping springs so easy that it can often be done without removing the actuator from the car! Note: that whilst this is a physical bolt on product, it should be considered a tuning tool as it WILL increase boost pressure and therefore TUNING IS REQUIRED.