A disc turbocharger includes a multi-disc engine in which each disc engine includes a turbine blade, a compressor blade, and a bearing without requiring a shaft between the turbine blade and the compressor blade. The power produced by each turbine blade is consumed by its own joined compressor. The disc turbocharger has a multi-disc engine that works as a multi-stage turbocharger with a smaller size and no piping between the turbochargers. The disc turbocharger uses a waste spool valve for control of the.