COBB Tuning Uppipe – Subaru Models (inc. 2006-2014 WRX / 2004+ STI)

Cobb Uppipe — 2006-2014 Subaru WRX / 2004+ Subaru STI

The Cobb Uppipe for the 2006-2014 Subaru WRX and 2004+ STI replaces the factory uppipe — the section of exhaust between the turbocharger outlet and the catalytic converter — with a free-flowing stainless steel unit. The factory uppipe is a known restriction that limits exhaust gas flow from the turbocharger, creating backpressure that reduces turbocharger efficiency and extends spool time. The Cobb uppipe eliminates this restriction with a larger-diameter, smoother stainless steel unit.

DETAILS

• Platform: 2006-2014 Subaru WRX EJ255 and 2004+ WRX STI EJ207/EJ257
• Replaces factory uppipe between turbocharger outlet and catalytic converter
• Larger diameter and smoother routing than factory — reduces turbo backpressure
• Stainless steel construction — corrosion resistant
• Improved turbocharger efficiency and spool characteristics
• Designed for use with Cobb Accessport Stage 2 and above OTS maps
• All gaskets and hardware included

Uppipe Function: The Critical First Pipe After the Turbocharger

The uppipe sits between the turbocharger’s turbine outlet and the catalytic converter — it is the first exhaust pipe after the turbocharger, and its flow characteristics directly affect the backpressure that the turbocharger’s turbine wheel must work against. The factory Subaru uppipe uses a small diameter and a routing with multiple bends that create turbulence and restriction in this critical location. Replacing it with the Cobb uppipe — larger diameter, smoother routing — reduces the backpressure the turbine sees, allowing it to spool more freely and extract energy from the exhaust stream more efficiently.

Stage 2 System Integration and Broad GD/GR Platform Coverage

The Cobb uppipe is a Stage 2 and above component — its primary benefit is realized when paired with a free-flowing downpipe or cat-back that allows the exhaust gas to move through the system without restriction downstream as well as upstream. On an otherwise stock exhaust system, the uppipe alone provides less benefit than when combined with a reduced-restriction cat-back. At Stage 2 with the FMIC and intake system optimized, the uppipe is the exhaust modification that completes the full-system flow improvement.

What’s in the Box

• Cobb stainless uppipe
• All gaskets, bolts, and hardware

Why Choose Cobb Tuning

Cobb Tuning has been developing performance software and hardware for turbocharged enthusiast vehicles since 1999. Founded in Austin, Texas, Cobb built its reputation on the Accessport and expanded into a full catalog of hardware engineered to complement it. Every OTS map is developed in-house on real vehicles, and every hardware product is validated as part of a complete system — not sourced and sold in isolation. That integrated approach is why Cobb produces consistent, reliable results across the builds we see every day.

The RallySport Take

The Cobb uppipe for the GD and GR WRX and STI is the correct exhaust component to address the factory turbocharger outlet restriction. For builds running the NexGen Stage 2 system or above, the uppipe is a meaningful addition that the Accessport Stage 2 maps account for when paired with a free-flowing cat-back. The broad platform coverage across GD and GR generations makes it the correct uppipe choice for this era of EJ-series Subaru builds.

Fitment

Year	Make	Model	Notes
2006-2014	Subaru	WRX	EJ255 MT
2004-2021	Subaru	WRX STI	EJ207/EJ257 MT