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IAG Performance

IAG - Stage 2 CNC Ported EJ25 11mm Oil Pump for 04-21 STI, 02-14 WRX, 05-12 LGT, 04-13 FXT

IAG - Stage 2 CNC Ported EJ25 11mm Oil Pump for 04-21 STI, 02-14 WRX, 05-12 LGT, 04-13 FXT


Regular price $449.00 USD
Regular price Sale price $449.00 USD
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IAG Stage 2 CNC Ported EJ25 11mm Oil Pump

The 11mm Subaru Oil pump is one of the most popular off-the-shelf pumps to use on EJ25 engines. Originally equipped on the 2008-21 STI Dual AVCS engines, it provides an adequate amount of pressure and flow that fits the needs of many OE and built engines. But, as with almost anything, there is room for improvement.

Increasing oil flow volume and pressure in an EJ25 ensures that the bearings have sufficient oil film under all power levels and driving conditions. Additional oil flow to the engine provides a greater oil reserve to operate the AVCS solenoids and cam gears - giving you more consistent performance results.

The IAG Stage 2 CNC Ported 11mm oil pump was developed over years of servicing street and racing engines. In that time IAG has tested and utilized the majority of the popular Subaru oil pumps available on the market (JDM, Cosworth, ACL, etc.) for the customer, personal and racing vehicles.

Over the last few years if you wanted an upgraded oil pump over the stock 11mm you would either buy a hand ported model from a trusted source or often an OEM JDM (Japanese Market) 12mm pump. We believe that we have developed a better alternative. The IAG Stage 2 CNC Ported 11mm oil pumps have shown through lab testing on a Spintron Machine that it will outperform a JDM 12mm.

Stage 2 flows 11.1% more oil than the OEM 11mm Oil Pump

Stage 2 flows 9% more oil than the OEM 12mm Oil Pump

The Stage 2 Oil pump is a cost-effective solution that outperforms the market standards. This pump has been extensively tested on streetcars, track cars, and on our in-house Spintron to ensure consistent and repeatable performance.

Each IAG Stage 2 oil pump starts life as an OEM spec 11mm oil pump, straight from Subaru. IAG completely disassembles the new oil pump including pulling the rotors, backing plate & pressure relief valve. Next, the main body is fixtured in our in-house 5-Axis Centroid CNC machine where the inlet and outlet passageways are CNC ported. This allows for a larger, more consistent pathway for the oil into and out of the gerotor internals and helps to prevent cavitation. The Oil Pump Outlet where it meets the engine block is also CNC “Port Matched”, for a perfect transition into the engine block. The Inlet and Outlet sides of the gerotor are also opened up on the CNC mill to reduce inlet side cavitation, and to reduce outlet side pressure drops.

The pressure relief valve piston is REM Polished, which provides a non-directional, low Ra, polished finish. This reduces friction, heat, and the possibility of the relief valve piston galling and sticking, a common failure point on the OEM pumps.

The piston is reinstalled and confirmed to operate correctly. The rotors are measured and checked to be within the manufacturer's specification - aka Blueprinted and installed next. The pump is then put together with a light coating of assembly lube to reduce friction and scuffing and aid in priming on the first startup.

Finally, the backing plate is installed. Loctite is added to the hardware, and each piece receives a painted mark after it is correctly torqued. The pump ships are ready to install, with all hardware and seals required for installation.


  • 11mm Oil Pump Rotors
  • Shimmed and REM Polished Pressure Relief Valve
  • Measured, Blueprinted, and Assembled
  • Packed with assembly lube
  • Ships ready to install with all required hardware
  • CNC Ported to maximize flow & pressure and reduce cavitation risks
  • Tested to outperform other commonly available pumps
  • Designed for Single and Dual AVCS engines
  • Great for IAG Stage 2 and up built engines used for street and competition cars
  • Fits all EJ series Subaru Engines


  • (x1) IAG 11mm Stage 2 CNC Ported Oil Pump
  • (x1) Front Crank Shaft Seal
  • (x1) Oil Pump O-ring
  • (x7) Oil Pump Zinc Plated Bolts



  • For use with IAG Stage 2 or higher (similar) engines.


  • SUBARU BAJA 2004-2006
  • SUBARU FORESTER XT 2008-2013
  • SUBARU OUTBACK XT 2005-2009
  • SUBARU WRX 2002-2014
  • SUBARU STI 2004-2021
  • SUBARU LEGACY GT 2005-2009
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