A turbocharged engine air system is disclosed. The engine air system includes at least two devices requiring vacuum, a turbocharger having a compressor fluidly connected to an intake manifold of an engine, a first evacuator and a second evacuator. The first evacuator defines a first motive section, a first discharge section, and at least two first suction ports. The first motive section of the first evacuator is fluidly connected to the compressor, and each of the at least two first suction ports are fluidly connected to one of the at least two devices requiring vacuum. The second evacuator defines a second motive section, a second discharge section, and at least two second suction ports. The second motive section of the second evacuator is fluidly connected to at least one of the at least two devices requiring vacuum.

The present invention relates to a vehicle braking arrangement for a vehicle with wheels contacting the ground during normal running. The vehicle braking arrangement includes an emergency brake control unit, a first emergency braking system including non-reversible braking means arranged to operate independently of the vehicle wheels, at least one acceleration detector, and a wheel brake anti-locking system. The emergency brake control unit is arranged to input acceleration data (a) when the wheel brake anti-locking system is active, and to calculate the coefficient of friction () between the wheels and the ground. The emergency brake control unit is arranged to determine if the first emergency braking system should be activated in dependence of a first plurality of parameters, where one of these parameters is the coefficient of friction ().

Devices for producing vacuum using the Venturi effect are disclosed that have a motive passageway converging toward a suction chamber, a discharge passageway diverging away from the suction chamber, and a suction passageway, all of which are in fluid communication with the suction chamber. The motive passageway has a single entrance, and subdivides downstream thereof into a plurality of subpassageways, one each leading to one of the plurality of motive exits, which are spaced apart from a discharge entrance of the discharge passageway to define a Venturi gap. The fletch having a plurality of ribs extending between an exterior surface of the generally conically-shaped main body thereof and an interior surface of the motive passageway is disposed in the motive passageway. The ribs divide the motive passageway into the plurality of sub-passageways, each converging fluid flow over the exterior surface thereof toward one of the plurality of motive exits.

A vehicle having a valve stop mode control unit configured such that an intake valve and an exhaust valve are stopped in a closed state during rotation of an output shaft, supply of fuel to an engine is stopped, a clutch is made to be in an engaged state, and pistons are driven by rotational forces from driving wheels through the output shaft. When there is a request for valve stop inertial running, a negative pressure is supplied to an intake passage by a vacuum pump.