High-Flow Performance Downpipe for 8V.2 RS 3 and 8S TT RS 2.5TFSI EVO (DAZA) – Now Available

Unitronic is pleased to announce its High-Flow Performance Downpipe for the 2017-2020 8V.2 Audi RS 3 and 2018-2020 8S TT RS equipped with the 2.5TFSI EVO (DAZA) engine. This downpipe is a direct bolt-on upgrade, designed to optimally eliminate unwanted restrictions in the factory downpipe, reduce turbo lag, and enhance the exhaust note, while utilizing a 5” 400cpsi ultra high output catalytic converter, designed in partnership with Unitronic, from our emissions partners at Global Emissions Systems Inc (GESi). GESi’s GEN2 ultra-high-output UHO+ catalytic converter was designed in conjunction with Unitronic for 2017+ Audi and Volkswagen applications, rated at up to 1000HP by GESi, and engineered to meet or exceed local emissions standards. Unitronic’s High-Flow Performance Downpipe comes bundled with the popular Unitronic Midpipes and when combined with its Stage 2 Performance Software, yields output of up to 621HP/564LB-FT with E85 and other supporting hardware modifications.

With Unitronic Midpipes: $1999.99 USD / $2599.99 CAD
Without Unitronic Midpipes: $1799.99 USD / $2339.99 CAD

Consistent with all of its performance products, Unitronic utilizes industry-leading tools, equipment, and computer-aided design software, packed with the latest technology from our partners at Creaform and Stratasys®. Combined, these tools and technologies are an immense resource, helping Unitronic achieve a design that not only optimizes airflow but eliminates restrictions while fitting perfectly in the constraints.

At Unitronic, development begins with setting the objectives; performance, efficiency, aesthetics, and quality. Operations start with 3D scanning the engine bays, exhaust tunnels, and OEM components with its in-house Creaform 3D scanner. Once 3D scan data has been collected and processed, Unitronic Hardware Engineers then interact with the 3D models to identify fitment constraints, mounting locations, other component locations, etc. to ensure the final product fits perfectly within the “envelope”, while achieving the objectives and intent of the product.

One key area of development for Unitronic Engineers was the Catalytic Converter on this High-Flow Performance Downpipe. While working closely with GESi through several iterations of their G-Sport Emissions Systems Catalytic Converters, our goal was to ensure this product would meet or exceed local emissions standards, while also satisfying the performance-related requirements, something that isn’t often achieved in the industry. Initial functional prototype testing began with GESi’s GEN1 UHO converters. Unitronic Engineers quickly identified a necessity to further improve the product on 2017+ Audi and Volkswagen models, through a multitude of data collection and testing, to once again ensure the product met or exceeded local emissions standards. Unitronic Engineers shared critical data with GESi while working through iterations. Fast-forwarding to the present, the Unitronic and GESi partnership has aided in the introduction of their GEN2 4.5″ UHO, 5″ UHO+, and 6″ UHOX catalytic converters, with the 5″ UHO+ variant being rated at up to 1000hp, while the 6″ UHOX variant rated at up to 1200hp.

Back to the initial design stage; evolution begins with rapid prototyping, utilizing Unitronic’s in-house Stratasys 3D printer. Within hours, Unitronic Engineers are able to have a printed prototype, allowing for test fitments to be performed on the vehicle, and other data to be collected to further validate the designs. Unitronic engineers studied what the Engineers at Audi had intended for the stock unit. The first aspect considered, was how to make it more efficient, yet effective. The design is in context with the OEM system to be consistent with the calibration models developed by Audi.

As with the original design, Unitronic also utilized the 1-to-2 split design. Following Audi’s modeling, Unitronic developed a large high-flow cast stainless steel downturn, increasing cross-sectional area, effectively improving flow and decreasing backpressure. Part of the design criteria was to maintain unbiased flow between the runners. Flow-through the large catalytic converter aids with flow distribution; and as a result, pressure and exhaust velocity are balanced to maintain efficiency and the distinct sound of the turbocharged 5-cylinder engine. The post-cat cast stainless steel transition continues, allowing for a smooth transition and flow distribution into dual 70mm T304 stainless steel tubing with OEM-style corrugated mesh flex bellows.

Unitronic’s pursuit for perfection is applied even in the most minute areas of product design and in this case, Unitronic identified that allowing for ample tolerance for engine movement on an item that is both affixed to a dynamic engine and a rigid chassis. Rather than using traditional flex bellow, Unitronic opted for an OE-style mesh flex, to ensure optimal range of motion is allowed. This offers a superior amount of flexibility over a traditional aftermarket-style flex section, while still offering the rigidity and strength to be highly reliable on the 2.5TFSI EVO engines.


• Cast Stainless Steel pre-cat downturn and post-cat transition

• Dual 70mm T304 Stainless Steel tubing

• TIG-welded construction

• GESi 5” G-Sport Ultra High Output UHO+ 400cpsi Catalytic Converter

• Factory catalyst placement for maximum efficiency

• OEM-style corrugated mesh flex bellows

• Proper factory Oxygen Sensor placement maintained

• OE exhaust hanger mounting provisions

• OE Prop-shaft heat shield bracket

• Direct bolt-on fitment

• Compatible with factory cat-back exhaust system


2017-2020 Audi RS 3 2.5TFSI EVO (DAZA)

2018-2020 Audi TT RS 2.5TFSI EVO (DAZA)

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