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SKU: 46997-4 | UPC: 807298041155
Manley 2004+ Subaru WRX/STI (EJ257) 99.75mm Bore 1.2mm x 1.2mm x 2.0mm +.25mm Oversized Ring Set
This Manley piston ring set fits 2004-2021 Subaru WRX/STI models equipped with EJ257 turbo engines after boring cylinders to 99.75mm. The 1.2mm x 1.2mm x 2.0mm configuration ensures precise cylinder sealing and effective oil control in engines handling elevated boost levels and RPM. Engine builders rely on these rings for rebuilt turbo setups that withstand intense performance demands.
Key Features
- Top Ring: High tensile strength steel with hard chrome face resists scuffing and holds seal integrity under high cylinder pressures
- Second Ring: Reverse bevel nitrided ductile iron promotes heat transfer and cuts friction for smoother operation
- Oil Ring: Three-piece design with steel top rail expander and flex-vent side rails meters oil consistently across all conditions
- Oversize Bore: 99.75mm (+.25mm) dimension matches overbored EJ257 blocks and coordinates with Manley pistons for exact fit
- Engine Specific: Designed exclusively for Subaru EJ257 turbo engines with optimized tension and gap settings for reliability
Product Notes
- Rings require end gap verification and filing to engine builder specifications for best results
- Best paired with forged pistons in high compression or boosted configurations
- Packaged to arrive undamaged and ready for inspection
Installation Notes
- Professional installation recommended.
- Set ring end gaps to 0.004-0.005 inch per inch of bore for top ring and follow specs for others
- Works with OEM heads gaskets and aftermarket pistons at 99.75mm bore diameter
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2004-2012 | Subaru | Impreza | WRX STI |
| 2004-2007 | Subaru | Impreza | WRX STI hatchback/sedan |
| 2007 | Subaru | Impreza | WRX STI Limited |
| 2008-2014 | Subaru | Impreza | WRX STI hatchback |
| 2010 | Subaru | Impreza | WRX STI Special Edition |
| 2011-2012 | Subaru | Impreza | WRX STI Limited |
| 2013-2014 | Subaru | Impreza | WRX STI |
| 2015-2021 | Subaru | WRX | STI |
Why Choose Manley?
- Over 30 years crafting engine parts for motorsports
- Built in USA facilities with tight tolerances for reliability
- Used in championship winning Subaru race engines
Frequently Asked Questions
-
Q: Does this fit all EJ257 engines in 2004+ STI models?
A: Yes for 2004-2021 Impreza WRX STI variants with EJ257 when cylinders are bored to 99.75mm -
Q: What ring materials are used?
A: Top ring is chrome faced steel second is nitrided ductile iron oil ring uses steel and flex vent components -
Q: What warranty applies and install tips?
A: Limited manufacturer defect warranty always gap rings precisely and torque to spec during assembly
Shipping & Handling
- Method: UPS Ground
- Availability: In stock - ships same or next business day
- Packaging: Secure box 5 x 5 x 1 inches
- Weight: 0.65 lbs
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