Turbosmart - Kompact Plumb Back Valve (Diverter Valce) Suit Mercedes AMG C63 M178 Bi-TurboKompact Plumb Back Valve (Diverter Valce) Suit Mercedes AMG C63 M178 Bi Turbo Turbosmart's Kompact valve kit offers a direct plug and play solution for the new C63 AMG. The Mercedes standard bypass valves, although intended for high performance, are plastic units prone to boost bleeding and pressure struggles, especially in tuned vehicles. Turbosmart's Kompact kit for the C63 features two billet aluminium valves, seamlessly replacing the factory