VF48 Turbocharger for Subaru WRX STI 2.5L EJ257 – OE Replacement & Performance Upgrade
Product Overview
The VF48 turbocharger is designed for the Subaru WRX STI 2.5L EJ257 engine, commonly fitted to North American models from 2008 to 2021. Based on the IHI RHF55 turbocharger platform, it is a popular choice for factory-style replacement and customized performance applications.
At Milewell, we offer the VF48 turbocharger with three compressor wheel configurations, giving turbocharger distributors, professional rebuilders, and performance workshops flexibility to select the appropriate version for their customers.
Whether you need a standard replacement or a customized turbocharger upgrade, we can help you identify a suitable configuration.
Three Compressor Wheel Options
1. OE-Size Compressor Wheel – Standard Replacement
This version uses an original-size compressor wheel configuration for customers looking to maintain factory-style turbocharger specifications.
- Original-size 6+6 compressor wheel design
- Suitable for standard replacement applications
- Designed around the original VF48 configuration
- Ideal for repair workshops and aftermarket distributors
2. GTX-Style 11+0 Billet Compressor Wheel – Performance Option
This upgraded version features an 11+0 blade billet compressor wheel with a GTX-style aerodynamic design.
- 11+0 billet compressor wheel
- Alternative blade geometry for customized performance builds
- Suitable for performance-oriented turbocharger applications
- Wheel dimensions and housing compatibility available upon request
3. Enlarged 11+0 Billet Compressor Wheel – Custom Upgrade
For customers requiring a larger compressor wheel, Milewell offers an upgraded 11+0 blade configuration with a 5-axis machined billet design.
- Enlarged 11+0 billet compressor wheel (diameter – Ø50.3/Ø68)
- 5-axis CNC-machined wheel geometry
- Intended for customized turbocharger upgrades
- Compressor housing matching and engine tuning may be required
The three configurations serve different replacement and performance requirements. Actual airflow capability, boost response, and horsepower depend on the final turbocharger specification, supporting modifications, and engine calibration.
Technical Specifications
| Item | Specification |
|---|---|
| Turbocharger Model | VF48 / RHF55 |
| Reference OE Number | 14411AA700 |
| Reference Part Numbers | VA440057, VB440057, VC440057, VD440057 |
| Engine | Subaru EJ257 2.5L Turbocharged Gasoline |
| Turbocharger Type | Single-Scroll |
| Bearing System | Journal Bearing |
| Cooling | Oil and Water Cooled |
| Wastegate | Internal Wastegate |
| Compressor Wheel Options | OE-Size 6+6 / GTX 11+0 / Enlarged 6+6 5-Axis Billet |
| Product Type | Complete Replacement / Upgraded Turbocharger |
Vehicle Applications
Subaru WRX STI 2.5L EJ257 – 2008–2021 (North American Applications)
- 2008–2014 Subaru Impreza WRX STI
- 2015–2021 Subaru WRX STI
OE Reference: 14411AA700
Please verify the original turbocharger part number, engine configuration, and installation requirements before ordering. Fitment for modified vehicles or other Subaru VF-series applications should be confirmed separately.
B2B Turbocharger Supply from Milewell
Milewell supplies replacement and customized turbocharger products to aftermarket parts distributors, repair workshops, and performance specialists.
For the VF48 series, we support inquiries for standard replacement units, upgraded compressor wheel configurations, and related turbocharger components.
Contact us with your preferred compressor wheel version, required quantity, and technical specifications.
Request a Quote for the VF48 turbocharger or discuss your customized turbocharger requirements with Milewell.







