A modular exhaust gas assembly includes a turbocharger housing having an exhaust flange and a bearing flange receptacle, and a plurality of turbine scrolls of different sizes for selective installation into the turbocharger housing in dependence on a power of an engine. Each turbine scroll has an inlet zone and is connected to the bearing flange receptacle via a selected one of a plurality of different bearing flanges and to the exhaust flange via a selected one of a plurality of different exhaust links. The inlet zone of each turbine scroll is configured to complement a contour of an outlet zone of a standard manifold so that the turbine scrolls are selectively connectable via their inlet zone to the manifold to suit the engine power at hand.