Abstract: A passive engine exhaust flow restriction arrangement includes a fixed geometry flow restriction mechanism disposed in line with an exhaust conduit. In one embodiment, the flow restriction mechanism is disposed upstream of a turbocharger turbine, and in an alternate embodiment it is disposed downstream of the turbine. In either case, the flow restriction mechanism defines a fixed cross sectional flow area therethrough that is less than the cross sectional flow area of the exhaust conduit. Preferably, the cross sectional flow area of the flow restriction mechanism is sized to optimize one, or both, of turbine efficiency and engine fuel economy.