Unitronic Downpipe for 2.5TFSI EVO

As with the original unit, Unitronic utilized the 1-to-2 split downpipe design. Following Audi’s modeling, Unitronic developed a large high-flow cast stainless steel downturn, increasing cross-sectional area, effectively improving flow and decreasing back pressure. Part of the design criteria was to maintain un-biased 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 Engineers thoroughly validated designs to ensure the Downpipe yields the results intended with several functional prototypes created. While working together with GESi, Unitronic tested several iterations of their G-Sport Emissions Systems Catalytic Converters to ensure the product meets or exceeds emissions standards and finally chose the GESi 5” G-Sport Ultra High Output UHO+ 400cpsi Catalytic Converter which is rated at up to 1000HP by GESi.