Wagner Tuning Audi TTRS 8J/RS3 8P Racing Catalyst Downpipe Kit

Wagner Tuning Audi TTRS 8J / RS3 8P Racing Catalyst Downpipe Kit

The Wagner Tuning Racing Catalyst Downpipe Kit is a direct-fit exhaust upgrade for the Audi TTRS 8J and Audi RS3 8P. It replaces the restrictive factory downpipe and pre-cat with a freer-flowing design, helping the turbocharger breathe more easily. The result is sharper throttle response, faster turbo spool, and a useful gain in torque across the rev range.

A downpipe is the section of exhaust that bolts directly to the turbocharger outlet. On standard cars, this section is deliberately restrictive to meet emissions targets. Opening it up reduces the back pressure the turbo has to fight against, allowing exhaust gases to exit more efficiently and the engine to perform closer to its potential.

How It’s Built

The kit uses a 90mm main pipe that splits into a twin 2 x 70mm outlet section, keeping flow smooth and consistent through to the rest of the exhaust. All pipework is manufactured from 1.4301 stainless steel (commonly referred to as SS304), a corrosion-resistant grade widely used in performance exhaust systems for its durability and finish.

Two high-flow racing catalytic converters are included, each rated at 100 cells per inch (cpi). A catalytic converter filters harmful gases from the exhaust stream. The factory cats use a much denser cell structure, which restricts flow significantly. At 100cpi, these racing cats offer far less restriction while still providing meaningful filtration. One lambda probe connection is retained so the engine management system continues to monitor exhaust gases correctly.

The factory pre-cat, which sits very close to the turbocharger, is removed in this design. This is one of the most effective ways to reduce heat soak around the turbo and free up exhaust flow where it matters most.

Key Benefits

• Reduced exhaust back pressure for quicker turbo response and improved power
• Noticeable torque gains throughout the rev range
• Lower thermal load on the turbocharger, which can help long-term reliability
• Compatible with the original main catalytic converters if you wish to retain them
• Direct fit replacement – no cutting, welding, or fabrication required

Technical Specification

Fitment

This kit is designed to fit the Audi RS3 8P and Audi TTRS 8J equipped with the 2.5 TFSI engine. This kit is not compatible with vehicles fitted with propshaft part number 8J0521101AB. Please use the vehicle lookup tool on this site or check the Vehicle Fitment tab to confirm compatibility with your specific car before ordering.

Important Notices

This product is intended for motorsport and off-road use only and is not road legal in all regions. It is the buyer’s responsibility to ensure compliance with local regulations before fitting. Removing or modifying emissions equipment may affect your vehicle’s MOT status and insurance.

An ECU remap is strongly recommended after fitment to take full advantage of the improved flow and to ensure the engine management system runs correctly with the modified exhaust setup.