Abstract: Methods for manufacturing an impeller wheel assembly (e.g., an impeller wheel attached to one or more additional components) are provided. In one example, a method includes casting an impeller wheel without a hub feature in a mold and holding the cast impeller wheel in a fixed position using a holding plate during subsequent stages of fabrication (e.g., the addition of a shaft via friction welding).

Abstract: Various systems are provided for a turbocharger center housing. In one example, a center housing for a turbocharger includes an internal water jacket including at least two ports, and a selectively pluggable interconnect positioned within the internal water jacket that, when plugged, blocks flow in the internal water jacket between the at least two ports in a first direction and, when unplugged, enables flow in the internal water jacket between the at least two ports in the first direction. In this way, flow may be directed through the center housing via different flow path configurations.

Abstract: A bearing system for a turbocharger includes a bearing housing having a first end and a second end, with the bearing housing defining a central passageway. A first ball bearing and a second ball bearing are received by the bearing housing. The second ball bearing is spaced from the first ball bearing. The first and second ball bearings are each preloaded.