SKU: 70020-AF108 | UPC: 4957266275559
HKS RS VAB VAF Air Intake System Subaru WRX STI EJ257 2008-2021
The HKS RS VAB VAF delivers a complete cold air intake upgrade for Subaru WRX STI models equipped with the EJ257 engine from 2008 to 2021. This system replaces the restrictive factory airbox with a high-flow dry filter and aerodynamic ducting to pull in cooler, denser air for noticeable gains in horsepower and acceleration. Drivers experience sharper throttle response and aggressive intake growl during hard shifts.
Key Features
- Dry Multi-Layer Filter: Progressive density design traps 99% of 5 micron particles while flowing 40% more air than stock for unrestricted engine breathing.
- FRP Resin Airbox: Lightweight fiber-reinforced plastic construction resists deformation under boost and heat for long-term durability.
- Integrated Heat Shield: Aluminum shield blocks engine bay heat to lower intake temperatures by up to 20 degrees F for denser air charge.
- Optimized Filter Angle: Slanted mounting position accelerates airflow velocity into the turbo inlet for improved spool and mid-range torque.
- Factory Bolt-On Design: Matches OEM mounting points with included adapters for seamless integration on STI EJ257 setups.
Product Notes
- Direct OEM replacement, no ECU modifications needed for daily driving.
- Clean filter every 10,000 miles or sooner in dusty conditions for peak performance.
- Packaged in sturdy HKS box to prevent damage during transit.
Installation Notes
- Professional installation recommended.
- Remove stock airbox and MAF sensor housing in 30-45 minutes.
- All clips, brackets, and silicone couplers provided for direct fit.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2008-2014 | Subaru | Impreza WRX STI | All (EJ257) |
| 2015-2021 | Subaru | WRX STI | All (EJ257) |
Why Choose HKS?
- Motorsport-proven designs from Super GT and rally programs.
- JDM manufacturing standards ensure exact tolerances and reliability.
- Dyno-tested power gains of 5-10 whp on stock STI EJ257 tunes.
Frequently Asked Questions
- Q: Will this fit my 2008 STI?
A: Yes, compatible with all 2008.5-2021 USDM WRX STI models powered by EJ257 engine, sedan body styles. - Q: What is the filter material and cleaning method?
A: Synthetic dry media, no oil required. Wash with mild soap, air dry, and reinstall for reuse up to 50,000 miles. - Q: Does installation require custom tuning?
A: No tuning needed for stock or lightly modified EJ257 engines, bolt-on and drive.
Shipping & Handling
- Method: UPS Ground or FedEx
- Availability: In stock – ships same or next business day
- Packaging: Original HKS box measures 15.75 x 11.42 x 8.66 inches
- Weight: 4.41 lbs





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