Abstract: A turbocharger can include a center housing; a bearing disposed in a through bore of the center housing where the through bore of the center housing defines a longitudinal axis; a shaft rotatably supported by the bearing; a compressor wheel operatively coupled to the shaft; a turbine wheel operatively coupled to the shaft; and a turbine housing assembly operatively coupled to the center housing where the turbine housing assembly includes: a turbine housing; and a cartridge that includes a nozzle wall component and a plate component that are spaced axially by spacers, where the nozzle wall component includes spacer bores for the spacers and where the nozzle wall component has a non-circular outer perimeter defined at least in part by arcs where adjacent arcs intersect at intersection points, and where each of the intersection points is radially outwardly from a respective one of the spacer bores.