This closed-circuit dump valve (silent operation) has been designed for BMW 235 3.0 Turbo petrol engines, as found on F22 chassis with electronically controlled bypass valve. This product is recommended for original vehicles and for vehicles whose turbo pressure has been increased by a modification of the ECU software, as a replacement for the standard bypass valve. Unfortunately, the standard plastic valve deteriorates over time and causes an engine check light. In addition, the valve may only partially function, and it is impossible to identify it as responsible for the loss of power. The valve can also dislocate when the turbo is disassembled, or in more extreme cases, it can be found inside the turbo, causing significant damage. The alternative offered by Forge offers greatly increased reliability. This valve works with a piston, to avoid fragile diaphragms, and is made of aluminum. It is also easy to maintain and the spring strength can be changed to suit higher turbo pressure levels. Most importantly, it retains the valve control via the ECU, with an electrical harness that plugs directly into the BMW's circuitry. It's literally plug and play. Only available in black