The IHI VF52 turbocharger is a direct bolt-on stock turbo for the 2008 – 2014 Subaru WRX. It also is an upgrade for the 2005 – 2009 Legacy GT/SpecB as well. The VF52 is an RHF55 turbo with the same compressor and turbine as the venerable VF48. So it is, in essence, an STI turbo. The difference is the two-bolt housing to fit WRX and LGT top mount intercoolers.
The VF48 uses the standard RHF55 divided journal and thrust bearing CHRA, F55-81H turbine and the model 479 Compressor wheel.
When upgrading an LGT or Forester proper tuning is necessary to ensure reliability and performance.