Devices for producing vacuum using the Venturi effect have a housing that defines a suction chamber, a motive passageway converging toward the suction chamber, a discharge passageway diverging away from the suction chamber, and a suction passageway having a first port in fluid communication with the suction chamber. Within the suction chamber, a motive exit of the motive passageway is spaced apart a distance from a discharge entrance of the discharge passageway to define a Venturi gap. A fletch that has a first hollow body section that terminates at or proximate a motive exit and a second hollow body section that terminates with a fletch entrance in fluid communication with the suction passageway upstream of the first port is present in the motive passageway. During operation, fluid flow through the motive passageway draws fluid flow through the first port into the suction chamber and through the fletch.