The VF22 is the largest VF turbo with a 48mm compressor housing and a 5 blade compressor wheel. The exhaust housing is a P20. This is the standard turbo on STi Version 2 (1996) and first 100 of the 22B (1998). This is a RHF5HB Ball Bearing type turbo. The VF22 has the largest potential for peak horsepower and highest boost levels in the IHI model range. It is capable of running up to 25 psi. Turbo lag is minimal, spool up is around 3300 rpm. Expect to max out the VF22 somewhere in the 400-450 hp range. Turbo is a direct bolt-in replacement for your WRX's factory unit, requiring no additional parts. This turbo breathes easier in the top and mid ranges, and has been known to give gains of about 20% in the horsepower department, and 30% in torque.