Air intake and exhaust systems for a snowmobile engine

A snowmobile comprising:

• a frame;
• at least one ski connected to the frame;
• an engine supported by the frame, the engine having an engine air inlet and an exhaust outlet;
• a turbocharger fluidly connected to the exhaust outlet and the engine air inlet, the turbocharger including:
• an exhaust turbine, and
• a compressor;
• an air intake system comprising:
• a first flow path connecting the compressor to the atmosphere;
• a second flow path connecting the compressor to the engine air inlet;
• an intake bypass flow path connecting the atmosphere to the engine air inlet for at least partially bypassing the compressor;
• and
• an intake bypass valve for controlling a flow through the intake bypass flow path;
• and
• an exhaust system comprising:
• a third flow path connecting the exhaust outlet to the exhaust turbine;
• a fourth flow path connecting the exhaust turbine to the atmosphere;
• an exhaust bypass flow path connecting the exhaust outlet to the atmosphere for at least partially bypassing the exhaust turbine;
• and
• an exhaust bypass valve for controlling a flow through the exhaust bypass flow path.

A snowmobile comprising:

• a frame;
• at least one ski connected to the frame;
• an engine supported by the frame, the engine having an engine air inlet and an exhaust outlet;
• a turbocharger fluidly connected to the exhaust outlet and the engine air inlet, the turbocharger including:
• an exhaust turbine, and
• a compressor;
• a first flow path connecting the engine air inlet to the atmosphere, the first flow path passing through the compressor;
• a second flow path connecting the exhaust outlet to the atmosphere, the second flow path passing through the exhaust turbine;
• an intake bypass flow path connecting the atmosphere to the engine air inlet for at least partially bypassing the compressor;
• an intake bypass valve for controlling a flow through the intake bypass flow path such that intake air can simultaneously flow through the first flow path and the intake bypass flow path from the atmosphere to the engine air inlet;
• an exhaust bypass flow path connecting the exhaust outlet to the atmosphere for at least partially bypassing the exhaust turbine;
• and
• an exhaust bypass valve for controlling a flow through the exhaust bypass flow path such that exhaust can simultaneously flow through the second flow path and the exhaust bypass flow path between the exhaust outlet and the atmosphere.