Forge Motorsport adjustable turbocharger actuator for Subaru Impreza II GDB

Adjustable actuator for the Subaru IHI VF35/VF34 turbocharger in the GDB body. Not suitable for the Spec C version.

Forge Motorsport developed and manufactured one of the first two-piece replacement turbocharger actuators made from aluminium. This version is intended for the IHI VF35/VF34 turbocharger and enables precise adjustment of actuator operation according to the vehicle and level of modification.

• Spring rate selection according to the vehicle
• Made from 6026-grade aluminium
• Vehicle-specific design
• Turbocharger-specific design
• Machined and hand-polished in the United Kingdom
• Diaphragm or piston sealing is available for most actuators
• Fluorosilicone diaphragms reinforced with Nomex fibres
• Laser-cut stainless steel brackets where required
• Adjustment and service kits are available
• Made in England

Actuator adjustment

The actuator is supplied as standard with a spring suitable for standard or slightly higher boost pressure. For modified vehicles, a stronger spring can be fitted on request when higher boost pressure is required.

Fitting the Forge actuator enables more precise adjustment of the required boost pressure, which can improve response and boost pressure control. The product is designed to increase the turbocharging system’s output boost pressure, but the adjustment must always be matched to the capabilities of the engine management system, whether it is an original or aftermarket system.

The standard version uses diaphragm sealing for the internal parts. Piston sealing is also available, providing comparable performance and reduced maintenance requirements thanks to the durable design of the piston internals.

The actuator is supplied as standard with the original spring. To use the FMPACTUN spring kit, the Diaphragm Type 2, 049 version must be selected.

All actuator rods are made from 303-grade stainless steel.

The stated spring pressure values according to the colour markings refer only to the mechanical aspect of operation and are directly applicable mainly to older turbo engines that are not controlled by an ECU or solenoid valve.

With modern engines controlled via an ECU or solenoid valve, the target boost pressure does not need to correspond to the spring’s mechanical specification. When selecting the correct spring for a specific model and planned level of modification, consultation with a qualified tuner is recommended.

The kit includes:

• 1 × FMAC2SUB actuator
• 1 × Forge sticker

Suitable for: Subaru Impreza II (GD/GG).