An impeller system with split impeller configuration between adjacent turbine wheels for synchronizing their thermal response is provided. Exemplary embodiments include a turbomachine having a turbine, a compressor and a rotor disposed between the turbine and the compressor, and an impeller system. An impeller system includes a turbomachine wheel, and another turbomachine wheel disposed adjacent to the first turbomachine wheel, a rabbet joint defined between the first and second turbomachine wheels and a split impeller disposed on the first and second turbomachine wheels.