Abstract: An adapter for a turbocharger allows an engine to operate naturally aspirated when the turbine-compressor cartridge is removed, as for repair, by procedures employing the method of the invention. A plate or a pair of plates or a plate plus conduit means for connecting the carburetor directly to the intake manifold are used to replace the turbine and compressor thereby completely closing off the turbine or the turbine and the compressor portions of the turbo housing. When, after the turbine-compressor cartridge has been removed, the compressor and turbine portions of the turbo housing are sealed in this manner, or the turbine portion has been sealed and the compressor portion bypassed, the engine will operate as a conventional, naturally aspirated, engine.