The Forced Performance blue XR turbocharger for Subaru WRX and STI applications features an 84mm CH8CM turbine housing with an internal wastegate and includes an oil feed line. The larger 84mm CH8CM turbine housing provides a different flow characteristic while the internal WG keeps boost control inside the housing. This XR 73HTZ 84mm variant suits WRX/STI setups that call for the larger CH8CM turbine and internal-wastegate configuration.
Forced Performance Subaru WRX/STI XR Blue 73HTZ Turbo 84mm CH8CM Turbine Hsg Internal WG w/Oil Line