An airflow system for an engine includes a first turbine coupled with a first compressor and a second turbine coupled with a second compressor. The first turbine receives exhaust from the engine, and the first compressor supplies compressed air to the engine. The second compressor compresses air from atmosphere. A first conduit fluidly couples the first and second turbines, and a second conduit fluidly couples the first and second compressors. A wastegate valve is fluidly coupled with the exhaust manifold and movable between a first position in which exhaust fluid is allowed to bypass the first turbine and a second position in which fluid is restricted from bypassing. The airflow system includes a third conduit fluidly coupling the second compressor and the wastegate valve. The wastegate valve moves to the first position when compressed air in the third conduit has at least a predetermined pressure.