A CHRA (Center Housing Rotating Assembly) otherwise known as turbo cartridge is a fast and easy way to repair your turbo with minimal downtime and tools needed. A CHRA consists of a new bearing housing, turbine shaft, compressor wheel, and all the other internal parts. A Cartridge Assembly is a fully assembled and balanced replacement component for your damaged or worn BorgWarner turbo. Simply bolt your existing compressor and turbine housing on this new assembly and you're back in business.
A complete turbocharger is essentially a Centre Housing Rotating Assembly (CHRA or core assembly) with housings fitted to each side. The turbine housing directs exhaust gas to power the turbine wheel, the compressor housing directs air into the engine. The turbine housing will have a wastegate to control the turbine speed, or as is more common on diesel engines, there is a variable vane mechanism giving much better control of the turbo, reducing lag and improving performance. The wastegate or vane mechanism is controlled by an actuator – which could be controlled either electronically or by a vacuum system.
The CHRA is a rotor (turbine wheel one side, compressor wheel on the other) which is held in a bearing system allowing it to rotate at high speed on a pressurised oil film similar to the engine. Turbo remanufacturer’s traditionally strip the complete turbocharger and CHRA, examine all the individual components, replacing these where necessary, and install brand new bearings and seals.
