turbocharger apparatus comprising a housing , a compressor , a turbine , a first inlet for enabling air to be conducted to the compressor , an outlet for enabling air from the compressor to be conducted to an engine , a second inlet for enabling exhaust gases from the engine to be conducted to the turbine , a chamber , a bearing assembly for permitting the rotation of the turbine , and a control system for controlling the speed of the turbine , the control system having an exhaust gas sealing system which prevents exhaust gas leakage from the turbocharger apparatus , and which allows expansion of parts within the exhaust gas sealing system at high temperatures .