Forge Motorsport Alloy Atmospheric Ram Dump Valve for Impreza V4
The Forge Motorsport Alloy Atmospheric Ram Dump Valve is specifically designed to fit the Impreza V4. Made from high-quality billet aluminium, this atmospheric diverter valve releases the charge-air to the atmosphere, creating the iconic “Whoosh” sound commonly associated with rally cars when the throttle is lifted. Not only does this valve enhance the auditory experience, but it also improves throttle response and provides a higher clamping load to maintain boost pressure more reliably.
This dual-piston atmospheric valve is equipped with a base port measuring 34mm in diameter. It has been meticulously designed and built to vent 100% of the residual charge air in your forced induction system to the atmosphere when the throttle is lifted. While Forge Motorsport has incorporated various elements into the valve’s design to ensure compatibility with mass air-flow sensor equipped vehicles, it is important to note that individual applications may vary. Therefore, Forge Motorsport and its Authorized Distributors cannot assume responsibility for any adverse effects resulting from the installation of this valve on a vehicle whose engine-management-system is not capable of compensating for the loss of metered air through a vent-to-atmosphere valve.
The Forge Motorsport Alloy Atmospheric Ram Dump Valve comes with the following items in the box: 1 x FMDVV4010 Valve, 1 x 34mm Blanking Plug, and 1 x Forge Sticker.
If you wish to tune this product to fit the needs of your engine, we recommend considering the spring tuning kit available separately. Fitting of this valve is also available at our performance workshop at Progressive Parts.

