IHI PERFORMANCE VF48 HIGH FLOW TURBO UPGRADE FOR 04-21 STI AND 02-07 WRX The IHI Performance VF48 High Flow Turbo Upgrade for 04-21 STI and 02-07 WRX is the perfect option for someone who wants to bolt on some serious power, with OEM quality, at a very affordable price point. This IHI VF48 high flow turbo upgrade spools early like a stock VF39, VF41, or VF48, and shares the same reliability and fitment of an OEM VF48 turbo, but it has been redesigned by IHI to flow more providing that extra power you crave. Up to 400+whp with E85, supporting mods and proper tuning. (Dyno Graph shown below) VF48 HIGH FLOW TURBO FEATURES This Subaru performance upgrade turbo was engineered to prevent compressor surge which tends to occur at low/mid rpms with the stock WRX / STI turbochargers. At high rpms, even using the same boost level, efficiencies are significantly improved over the stock WRX / STI turbochargers. It spools ultra quick, not at all laggy like some of the bigger bolt on Subaru turbos can be. Torque is smoother on the road and not as binary, making this a perfect option for daily drivers and vehicles that will be used on the track. This turbo has just been submitted for CARB approval as well! Precise machined aluminum forged big compressor wheel for quicker spool The appropriate shaped larger compressor shroud adopts an abrade-able seal structure that further improves turbocharger efficiency. 100% Bolt-on Installation Engine supporting modifications will be needed to gain full performance potential (400+ whp with e85, at 18.5 psi) Installation: BOLT-ON Recommend for track usage: ECU tune plus Inlet & Exhaust Upgrade Applicable model : 2004-2006 2.5L (OEM TURBO UNIT MARKING: VF39) 2007 2.5L (OEM TURBO UNIT MARKING: VF43) 2008-2021 2.5L (OEM TURBO UNIT MARKING: VF48)   Compressor Specifications Compressor Type: Precise machined aluminum forged big compressor wheel for quicker spool Compressor Wheel OD (exducer): 62mm (Stock STI is 60mm) Compressor Wheel Inducer: 48.32mm (Stock STI is 46.5mm)   Compressor Housing Connections: Inlet: OEM 04+ STI Outlet: OEM 04+ STI   Turbine Specifications Turbine Inlet Flange: See reference #3 below Turbine Housing Size: P18 Turbine Inducer: 53mm Turbine Exducer: 48mm Technical Reference Drawing #3 Power numbers: With supporting mods, 400+ whp is easily accomplished while retaining the stock reliability of an IHI turbocharger.   CALIBRATION AND TUNING INFO 1. WASTEGATE ACTUATOR If the turbocharger unit which you select has the adjustable turn-buckle actuator, please use precise boost gauge and be sure to fasten the nuts of the turn-buckle function on actuator rod when adjusting it. 2. BOOST PRESSURE CONTROL To control boost pressure, a boost controller is necessary separately. 3. ENGINE CONTROL PARAMETERS Premium pump gas or e85 required NOTES Installation of the product should be performed by a person with appropriate qualifications and knowledge to follow the method described in the vehicle’s service manual. Subaru highly recommends purchasing a new Banjo Bolt and Screen (SUB 14445AA090) with any purchase of a new OEM turbo.​ This turbo may also bolt onto other model years of WRX / STI, but supporting modifications may be necessary. This product is intended to be used only on racing vehicles on closed courses, and not for use on roads or vehicles otherwise subject to emission control requirements. Please check legality of aftermarket products with your country, local state, county, city authorities before purchasing. In USA, this product should not be used on any vehicles that is registered or licensed for use on public roads.