as direct injection fuel injector 66 delivers liquid fuel in proportion to the pulse width from controller 12 fuel is delivered to fuel injector 66 by a fuel system not shown including a fuel tank fuel pump and fuel rail not shown in one example a high pressure dual stage fuel system may be used to generate higher fuel pressures in addition intake manifold 44 is shown communicating with turbocharger compressor 162 and engine air intake 42 in other examples compressor 162 may be a supercharger compressor shaft 161 mechanically couples turbocharger turbine 164 to turbocharger compressor 162 optional electronic throttle 62 e g central or engine intake manifold throttle adjusts a position of throttle plate 64 to control air flow from compressor 162 to intake manifold 44 pressure in boost chamber 45 may be referred to as throttle inlet pressure since the inlet of throttle 62 is within boost chamber 45 the throttle outlet is in intake manifold 44 in some examples throttle 62 and throttle plate 64 may be positioned between intake valve 52 and intake manifold 44 such that throttle 62 is a port throttle compressor recirculation valve 47 may be selectively adjusted to a plurality of positions between fully open and fully closed waste gate.