Fits: 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 Impreza WRX STI

Out of stock


The IAG Stage 1 Short Block is perfect for lightly modified EJ25 Subaru’s that need a basic and reliable performance short block. Subaru turbo engines are commonly known for piston ring land failures and if gone unchecked lead to rod knock and total engine failure due to oil starvation from blow by. IAG’s Stage 1 Short Block includes upgraded forged pistons along with performance main and rod bearings that replace the OEM components that are prone to common failure on Stage 2 and up vehicles. Each IAG Stage 1 Short Block starts with a new Subaru 2.5L 99.5mm bore EJ25 engine case halves as standard. The short block is measured and assembled using a new 2017+ Nitride Treated Subaru 2.5L STI crankshaft that is matched to ACL or King main bearings. Early style OEM STI rods are utilized along with ACL or King rod bearings. The case halves are sealed with new OEM case bolts and sealant. Finally, 99.5mm IAG-Spec JE Forged Pistons are spec’d and installed finishing off the short block.

Power: The IAG Stage 1 Long Block has a power output rating of 475BHP.

Stage 1 Short Block Includes:
Case Halves – Brand new Subaru OEM case halves 99.5mm Stock Bore
Pistons – IAG-Spec JE 99.5mm Forged Pistons, Ring Set, .180″ Chromoly Steel Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pin)
Connecting Rods – Early OEM (Stronger Style) STI rods
Rod / Main Bearings – ACL or King Bearings
Crankshaft – Standard New Subaru Nitride Treated 2017+ STI Crankshaft
Case / Main Bolts – Standard FHI Subaru case bolts

Cylinder Heads:
OEM W25 Dual AVCS Cylinder Heads
OEM Camshafts
OEM Valve Train

Compression Test:
Cylinder #1 – 130 PSI
Cylinder #2 – 130 PSI
Cylinder #3 – 130 PSI
Cylinder #4 – 130 PSI

Leak down Test:
Cylinder #1 – 7%
Cylinder #2 – 7%
Cylinder #3 – 3%
Cylinder #4 – 7%

The engine is in excellent condition and will not disappoint! It also comes with a 30 day warranty for peace of mind. Price listed is shipped to a business address with a forklift or loading dock. If you do not have either, we can ship it to your residential address, for $100 to 300 extra depending on where you are located. If you have any questions regarding this engine, feel free to send us a message.