IAG Stage 2 TUFF 2.5L Subaru Short Block For WRX, STI, Legacy GT & Forester xT
IAG Stage 2 Tuff Short Block
The IAG Stage 2 Tuff short block starts with new Subaru 2.5L EJ25 engine case halves that are bored and honed to 99.75 on our in-house Sunnen SV-30 the most advanced automotive cylinder hone available. IAG's in-house honing process is able to set piston to wall clearances tighter for a quieter running engine. The short block is measured and assembled using a new 2017+ Subaru 2.5L nitride treated STI crankshaft that is matched to ACL or King race main bearings. Next, IAG-Spec Tuff H-Beam rods with ARP Rod Bolts are utilized to increase the power rating slightly at the expense of being slightly heavier. The connecting rods are matched to ACL or King race rod bearings. The case halves are sealed with new OEM main case bolts and sealant. Finally, IAG-Spec JE 99.75mm Forged Pistons are added to finish off the short block.
Stage 2 Tuff Short Block Includes:
- Case Halves - Brand new Subaru OEM case halves, bored and honed to 99.75mm.
- Pistons - IAG-Spec JE 99.75mm Forged Pistons, Ring Set, .210" 9310 Steel Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pin)
- Connecting Rods - IAG-Spec Tuff H-Beam / ARP2000 Rod Bolts.
- Rod / Main Bearings - ACL or King Race bearings.
- Crankshaft - Standard New Subaru Nitride Treated 2017+ STI Crankshaft.
- Case / Main Bolts – Standard FHI Subaru case bolts.
Additional Options Available:
- Oil Pump - Subaru JDM 12mm High Volume Oil Pump - $219 or 11mm Subaru Oil Pump - $199.95
- IAG Oil Pickup - Upgraded oil pickup featuring heavy gauge steel tubing, 2 point bracket & mesh filter - $129.99
- IAG Oil Baffle - Upgraded oil control baffle and windage tray - $199.99
- IAG Oil Pickup & Baffle Set - Upgraded oil pickup, oil control baffle, and windage tray - $299.99
- Hardware / Seals - OEM cover and seal kit - $105.99
- 8.5:1 on D Cylinder Heads (EJ255)
- 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
Power: The IAG Stage 2 Tuff Short Block has a power output rating of 600BHP.
*All IAG short blocks are balanced and blueprinted.
Oil Pickup / Oil Control Baffle / Windage Tray Options:
The IAG Performance Subaru WRX / STI oil pickup was designed by Tigwerks to replace the OEM EJ25 oil pickup, which is prone to failure. It’s a well-known fact that the OEM oil pickups often crack and fail which, in most cases, destroys your engine from lack of oil pressure. To avoid the cracking failures seen in the OEM oil pickup tubes, the Tigwerks oil pickup is manufactured from heavy-gauge steel tubing that is 3x thicker than OEM. Additionally, it features a flange machined from 3/8” 1018 CR steel to mate with the block, sealed with a Viton O-ring. The integrated heavy-duty mounting bracket uses two mounting points rather than the OEM single mounting point. Furthermore, the oil pickup features a formed bottom with an OEM style mesh screen for proper filtration. The TIG-welded oil pickup's increased material thickness, matched with the two-point heavy-duty mounting bracket, helps ensure that it does not fatigue and fail over time like an OEM unit.
The IAG Oil Control Baffle and Windage Tray System is designed to limit potential blow-by and prevent oil starvation in your Subaru’s WRX / STI EJ engine during high rpm and high g-force driving. Through the use of Viton one-way flapper valves on our baffle and louvers in our windage tray, oil is prevented from reentering the upper crankcase area and is directed down into the oil pan to ensure plentiful supply to the oil pickup. IAG’s integrated two-piece Oil Control Baffle and Windage Tray System is designed to work with our own oil pickup, as well as other oil pickups*. The baffle fits neatly in the engine crankcase area, allowing normal installation of the OEM oil pan and popular aftermarket pans*.
Oil Pickup & Baffle Install Notes
- EJ20 Subaru WRX engines require EJ25 oil pans for fitment
- IAG oil pickup spacer (Part# IAG-ENG-2081SP) is required when using IAG oil pickup with Killer B Oil Pan.
- *Does not work with Moroso oil pans or pickups
Hardware / Seal Option:
Not planning on reusing your original short block service plugs and covers? IAG offers a simple comprehensive OEM cover and seal kit that includes (1) Rear main seal, (3) wrist pin plugs, (3) wrist pin plug washers, (1) separator cover, (6) separator cover bolts, (1) wrist pin service cover, (1) wrist pin service cover O-ring and (2) wrist pin service cover screws. *If you are reusing your original wrist pin service plugs and covers always replace the (3) wrist pin plug washers and (1) wrist pin service cover O-ring before installing a short block to avoid potential leaks. *Never reuse a rear main seal on a new short block.
Please review the PDF document below regarding installation, break-in procedures and warranty information.