IAG Performance Adjustable Timing Idler Kit Subaru EJ20/EJ25 | IAG-ENG-5120

Product Fitment: 

2002-2014 Subaru WRX

2004-2021 Subaru STI

2004-2008 Subaru Forester XT

2005-2009 Subaru Legacy GT Outback XT

Developed through years of motorsport testing, the IAG Performance Adjustable Timing Idler Kit is the go-to solution for aligning cam timing on resurfaced Subaru EJ20 and EJ25 engines. Originally engineered by LIC Motorsports and refined by IAG for wider distribution, this proven design corrects timing discrepancies caused by changes in long block length due to head resurfacing, block decking, or the use of thicker head gaskets.

Each idler is precision CNC-machined in-house and features an eccentric center with a 10mm hex for easy adjustment. Whether you're building a high-performance street car or track-ready machine, this kit is an essential tool for achieving accurate camshaft alignment.

Features:

• Vehicle Fitment: Designed for Subaru EJ20 and EJ25 engines

• Corrects Cam Timing: Ideal for engines with resurfaced heads/blocks or thicker head gaskets

• Precision Adjustment:

  • Idler #1 adjusts RIGHT (passenger side) intake/exhaust cams

  • Idler #2 adjusts LEFT (driver side) intake/exhaust cams

• CNC Machined: Precision-made from high-quality materials for perfect fit and reliability

• OEM Quality Bearings: Single roller bearing design for smooth, reliable operation

• Easy Adjustment: 10mm hex machined into each idler for accurate timing alignment

• OEM Tolerances: Manufactured to meet strict OE specs for performance and durability

• IAG Branding: Each unit is laser-engraved with the IAG logo

Kit Includes:

• (2) Adjustable Idlers with CNC-Machined Eccentrics

• (2) M10 Zinc-Plated Mounting Bolts

Installation & Maintenance Notes:

• Professional installation by a Subaru engine specialist is strongly recommended

• Idlers should not be used to compensate for excessive machining or components more than one tooth out of alignment

• Threaded mounting areas must be inspected thoroughly before installation

• Maintenance Schedule:

  • Street Use: Replace every 60,000 miles

  • Race/Track Use: Replace annually or at every engine teardown