IAG Unequal Length 3-Bolt Header & Uppipe 02-14 WRX / 04-21 STI / 05-09 Legacy GT / 04-08 Forester XT | 304 Stainless Steel | Performance Exhaust Header Kit
Overview
The IAG Unequal Length 3-Bolt Header & Uppipe is a high-performance exhaust upgrade designed specifically for a wide range of Subaru models including the WRX, WRX STI, Legacy GT, and Forester XT. This header and uppipe combo enhances exhaust flow with its 45mm diameter pipes and unequal length design, delivering improved power and throttle response while preserving the signature Subaru Boxer engine sound. It’s ideal for enthusiasts seeking a reliable, durable upgrade that supports both street and track driving.
Constructed entirely from premium 304 stainless steel, including cast stainless flanges, this header set is built for longevity and resistance to heat and corrosion. The design incorporates a slip-joint expansion section to accommodate thermal expansion and reduce stress on the exhaust system. Fully TIG welded for strength and precision, the IAG header and uppipe package includes all necessary hardware and multi-layer gaskets to ensure a leak-free, secure installation. IAG’s engineering expertise shines through in the attention to detail and quality control, making this a standout option for Subaru owners.
By improving exhaust scavenging and flow dynamics, this header and uppipe combination unlocks power gains across the entire RPM range, enhancing acceleration and overall engine efficiency. The inclusion of specialty copper flange nuts and zinc-plated bolts ensures durability under extreme heat cycling conditions common in turbocharged Subaru engines. This upgrade is a practical and effective way to elevate your Subaru’s performance while maintaining reliability and the iconic Boxer rumble.
Features & Specifications
This IAG Performance header and uppipe kit is engineered for Subaru WRX, WRX STI, Legacy GT, and Forester XT models, featuring 304 stainless steel construction and a 45mm pipe diameter for optimal exhaust flow and durability. Designed to improve power delivery and maintain OEM-level reliability, it is a direct bolt-on solution with included hardware and gaskets for a complete installation.
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Brand: IAG Performance
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Product: Unequal Length 3-Bolt Header & Uppipe
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Part Number: IAG-EXT-1000
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Fitment: 2002-2014 WRX, 2004-2021 WRX STI, 2005-2009 Legacy GT, 2004-2008 Forester XT
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Material: 304 Stainless Steel
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Finish: Natural Stainless Steel
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Construction: Fully TIG Welded, Cast Stainless Flanges
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Origin: Not Specified
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Pipe Diameter: 45mm
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Expansion Joint: Slip-Joint Section for Heat Cycling
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Included Hardware: Copper Flange Nuts, Zinc-Plated Bolts and Studs
Key Benefits
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Performance: Improves exhaust flow for power gains across the entire RPM range
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Durability: 304 stainless steel construction resists corrosion and withstands high temperatures
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Fitment: Designed specifically for multiple Subaru platforms with included hardware for a secure, leak-free installation
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Reliability: Slip-joint expansion accommodates thermal expansion, reducing stress and preventing cracks
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Sound: Maintains the iconic Boxer rumble that Subaru enthusiasts value
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Quality: Fully TIG welded with cast stainless flanges for strength and precision
What's Included
- 1× IAG Unequal Length Stainless Steel Header
- 1× IAG 3-Bolt Stainless Steel Uppipe (60mm)
- 1× 3-Bolt Uppipe Gasket
- 3× Uppipe to Manifold Zinc Plated Bolts and Nuts
- 5× Uppipe to Turbo Threaded Studs
- 1× EGT Plug
- 6× Copper Flange Nuts (Manifold to Head)
- 2× Manifold to Cylinder Head Gaskets
- 1× Uppipe to Turbo Gasket
Installation & Compatibility
Installation of the IAG Unequal Length Header & Uppipe requires moderate mechanical skill and some special considerations. The package includes all necessary hardware and gaskets, but slight modifications to the passenger side U-frame are required on 2002-2007 WRX/STI chassis. Additionally, certain model years require STI oil pans and oil coolers for proper fitment. Professional installation is recommended to ensure proper torque and alignment, especially given the thermal expansion design features and the importance of leak-free sealing.
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Professional Installation: Recommended
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Modifications Required: Slight passenger side U-frame modification on 2002-07 WRX/STI; STI oil pan and oil cooler required on select years
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Verify Compatibility: Confirm fitment for your specific year and trim level before purchase
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