Direct Fit Piston Recirculation Valve


Code: FMDVK04S

  • CNC machine body and internals
  • Tuneable, for different boost pressures
  • Serviceable, for lifetime use
  • Easy Fit, full step by step installation instructions provided
  • Utilising world leading springs for more precise operation and consistency
  • Assembled with heat stabilised Viton O rings
  • Lubricated with Mobil 1 high temp grease
  • Covered by the unique Forge Lifetime Warranty *

This recirculating valve is a direct replacement for the OEM valve but offering a level of reliability that is second to none!  The vacuum nipple is position is angled making the upgrade/replacement seamless. We take pride in producing valves that have significant advantages over to original equipment: the body and internals are machined in our workshop in Gloucester, UK. They are then hand polished or anodised black for the stealthy appearance.

If stealthy isn’t your style and you want the infamous dump valve noise, take a look at our atmospheric version: FMDVK04SA

Please note for Porsche 997 Generation 1, x2 FMDVK04S's are required.

*Product demonstrated in the photo above fitted to the turbo features FMDVK04D, the same valve with a top exit vacuum nipple

The OEM valve uses a rubber diaphragm and a plastic housing. Both of these materials, but especially the rubber is prone to failure. The rubber can stiffen and go brittle due to the heat from the engine, resulting in the diaphragm splitting and boost leak.

Our valve uses full billet alloy construction with a piston based internal design, meaning the issues with the OEM can never happen with ours! To give you even more peace of mind, we made the internals of our valve serviceable. We recommend doing these every 3 years or 20,000 miles, whichever comes first. However, if you don’t want to service your valve yourself you can order the kit and ship your valve back to us and we will carry out the service free of charge! Simply contact us to arrange the service!

The OEM valve internals can also fail if you have your vehicle mapped as the rubber diaphragm is not always strong enough to cope with the increased boost pressure. We build our valves with a spring matched to the original pressure of the car but include in the kit a spring strong enough to cope with a stage one remap. If you decide to increase the power even more, you can guarantee the reliability of our valve by using this spring tuning kit!


In the Box
1 x FMDVK04S Valve
1 x Uprated Yellow Spring
1 x Forge Sticker



  • Buick
    • Regal Turbo 2.0
  • Chevy
    • Cobalt SS
  • Ford
    • Focus > RS MK2
    • Focus > ST225
    • Fusion > 2.0
    • S-Max > 2.5 Petrol (Gen 1 2006-2014)
  • Opel
    • GT Roadster
  • Pontiac
    • Solstice GXP
  • Porsche
    • 997.1/911 Turbo
  • Range Rover
    • Evoque > Petrol
  • Saturn
    • Sky Redline
  • Volvo
    • C30 T5 FWD 2007-2013
    • C70 T5 FWD 2006-2013
    • V40/S40 T5 > AWD 2005-2010
    • V40/S40 T5 > FWD 2004-2011
    • V50 T5 > AWD 2006-2010
    • V50 T5 > FWD 2005-2011
    • V60/S60
    • V70R