Turbine assembly

A turbocharger comprising:

• a center housing that comprises a through bore;
• a compressor housing coupled to the center housing;
• a turbine housing coupled to the center housing;
• a bearing disposed in the bore of the center housing;
• a shaft and turbine wheel assembly rotatably supported by the bearing in the bore of the center housing;
• a compressor wheel coupled to the shaft and turbine wheel assembly;
• and
• a pinched nozzle cartridge that comprises a base component, an insert component and vanes disposed at least in part between the base component and the insert component,
• wherein the insert component comprises a shroud surface and an upper pinch profile,
• wherein the base component comprises an annular surface that defines a turbine wheel opening and a lower profile and
• wherein the upper pinch profile and the lower profile form a pinched nozzle.