GSC Power Division 7025S1 Billet S1 Camshafts for 2004-2007 Subaru WRX/STI

Vehicle Fitment

• 2004-2007 Subaru Impreza WRX / WRX STI (EJ25 engine, intake-only AVCS configuration)
• Compatible also with 2006-2014 WRX (EJ25 with intake AVCS) when used with correct AVCS setup

Features

• CNC-machined billet camshafts for higher durability and precision than cast cams
• S1 profile - balanced performance: no loss of low-end, with broader power across RPM range
• Ideal for stock or upgraded turbo setups - supports up to ~500 WHP with proper supporting mods
• Intake & exhaust lobes ground with high-precision for smoother operation and reliable valve timing under load
• Dark-nitride coating for improved wear resistance, corrosion resistance, and reduced friction
• Provides increased valve lift and duration - enhances airflow for improved torque and horsepower gains
• Direct-fit replacement - designed for EJ25 heads with intake AVCS, minimal modification required (check clearance)
• Engineered for reliability under performance conditions - suitable for daily drivers, tuned street builds, or track use

Specifications

• Part Number: 7025S1
• Camshaft Type: 7000-Series Billet "S1" Profile
• Intake: 264° advertised, 226° @ 0.040", Peak Lift ~10.80 mm, Centerline 125° (AVCS compatible)
• Exhaust: 264° advertised, 222° @ 0.040", Peak Lift ~10.50 mm, Centerline 115°
• Use Case: Stock to ~500 WHP turbo builds, mild-to-moderate performance upgrades
• Finish: Dark-nitride coating (wear and corrosion resistant)
• Included: Full set of 4 camshafts (intake + exhaust, left & right bank) for DOHC EJ-series head

Included Components

• 1x Full set of 4 billet camshafts (7025S1 - intake & exhaust) for EJ25 head

Product Description

The GSC 7025S1 billet S1 camshaft set is a popular and proven performance upgrade for 2004-2007 Subaru WRX / WRX STI (EJ25, intake-only AVCS) - and is also used on later WRX models with correct AVCS setups. Designed as a drop-in billet replacement of OEM cams, S1 delivers a smooth, broad powerband without sacrificing low-end response. With its 264° cam profile, ~10.8 mm intake lift and ~10.5 mm exhaust lift, the S1 improves airflow and combustion efficiency - especially useful if you are running a stock turbo or moderate upgrade (up to ~500 WHP) and want more torque and power across the rev range.:contentReference[oaicite:1]{index=1}

Manufactured from billet and ground on precise CNC equipment, these cams are more durable and repeatable than cast camshafts, offering stronger resistance to wear and fatigue under aggressive driving or tuning. The dark-nitride finish enhances longevity and reduces friction, while the profile and duration ensure you retain usable drivability and street manners. Because they are designed specifically for EJ25 heads with AVCS, installation is straightforward - though some minor head casting clearance work may be required depending on head condition. Upgraded valve springs (such as beehive or performance springs) are strongly recommended to handle the increased lift and duration reliably.:contentReference[oaicite:2]{index=2}