Turbosmart Kompact Dual Port BOV Suit Mercedes AMG C63 M178 Bi-Turbo

Turbosmart™s Kompact valve kit has been developed as a direct plug-and-play solution for the new C63 AMG. Despite its high-performance intentions, the Mercedes™ standard bypass valves are plastic units that bleed boost and struggle to cope with the pressure, particularly in tuned vehicles.
Turbosmart™s Kompact kit for the C63 comes with two billet aluminium valves that are a direct fit replacement for the factory diverter valves. The Kompact holds a boost in better than the factory valves and can never be overcome by a boost. The result is the more efficient performance from the factory turbochargers and the crisp sound of a piston-style BOV. For those who want blow-off valve sound, the Dual Port both vents-to-atmosphere as well as recirculates air, while the Plumb Back is 100% recirculating for quiet, OEM-style operation. 
Unlike the factory valves, the Turbosmart replacement kit is mechanically controlled by manifold pressure, meaning the valves open when you want them to, not when a computer decides they should. This puts control back in the driver™s hands and ensures the valves do not release boost when they shouldn™t.