Korsh Unequal Length 3-Bolt Header & Up-Pipe – Subaru WRX 94–14 / STI 02–21 / Liberty GT 05–09 / Forester XT 04–08

The Korsh Unequal Length Header and Up-Pipe system is designed for Subaru enthusiasts who want to increase exhaust flow and performance while retaining the unmistakable boxer rumble. Manufactured from high-quality 304 stainless steel with cast stainless flanges, this setup delivers durability, reliability, and consistent performance under extreme heat cycling.

The unequal length design features a 45 mm primary pipe diameter to maximise exhaust gas velocity and improve flow across the entire RPM range. A free-flowing layout helps unlock noticeable gains in throttle response and mid-to-top end power, while a built-in slip-joint expansion section allows for thermal movement, reducing stress and improving long-term reliability. All welds are fully TIG welded for maximum strength and precision.

The included 60 mm 3-bolt up-pipe uses a cast stainless flange and multi-layer steel gasket to ensure a secure, leak-free connection between the header and turbocharger. The kit also includes all required hardware and premium gaskets, including copper exhaust nuts proven to maintain clamping force even under repeated heat cycles.

Key Features

• Unequal length design to retain the iconic Subaru boxer rumble
• 304 stainless steel construction with cast stainless flanges
• 45 mm primary piping for improved exhaust flow and performance
• Slip-joint expansion section to accommodate heat cycling
• Fully TIG welded for strength and durability
• 60 mm 3-bolt stainless steel up-pipe included
• Includes titanium heat wrap for improved thermal management

What’s Included

• Unequal length stainless steel exhaust header
• 3-bolt stainless steel up-pipe
• 3-bolt up-pipe gasket
• Up-pipe to manifold zinc-plated bolts and nuts (x3)
• Up-pipe to turbo threaded studs (x5)
• EGT plug
• Copper flange nuts – manifold to head (x6)
• Manifold to cylinder head gaskets (x2)
• Up-pipe to turbo gasket

Fitment Notes

• 2002–2005 WRX requires STI 2.5L oil pan
• 2006–2007 WRX requires STI oil cooler and STI oil pan
  
• 2004 Forester XT requires STI oil cooler and STI oil pan
• 2005–2008 Forester XT requires STI oil cooler
• 2005 Liberty GT requires STI oil pan

This system is ideal for street and performance builds looking to improve exhaust efficiency while preserving Subaru’s signature sound.