GSC S1 Billet Camshaft Set – Subaru EJ255 / EJ257 Intake AVCS (GSC7025S1)
Turbo-Responsive Cam Upgrade for EJ Builds
The GSC Power-Division S1 Billet Camshaft Set is designed for USDM Subaru WRX and STI models equipped with intake-only AVCS. These cams maintain low-end drivability while enhancing turbo spool, midrange torque, and overall power delivery. Ideal for stock-location turbo upgrades or builds targeting up to 500 WHP.
Spring & Installation Requirements
- Upgraded valve springs are required for safe high-RPM operation
- Beehive springs are recommended but not mandatory
- Head castings may require minor clearance due to lobe size
- Flat tappet engines must use high-zinc oil and follow proper break-in procedures
- Professional installation is strongly advised
Camshaft Identification
Refer to product images for cam placement:
Long nose = Left Side
Short nose = Right Side
Camshaft Specifications
| Camshaft | ADV Duration | Duration @ 0.040" | Peak Lift | Center Line |
|---|---|---|---|---|
| Intake | 264° | 226° | 10.80mm | 125° |
| Exhaust | 264° | 222° | 10.50mm | 115° |
Fitment Guide
- 2004–2007 Subaru WRX STI 2.5L Turbo DOHC (EJ257 Intake AVCS)
- 2006–2014 Subaru WRX 2.5L Turbo DOHC (EJ255 Intake AVCS)
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