Milltek Sport Large-Bore Downpipes are designed to deliver noticeable gains in both performance and exhaust sound. Featuring a larger diameter compared to factory OEM pipes, they allow exhaust gases to flow more freely, reducing back pressure and improving overall engine efficiency. When paired with the Milltek Catalyst Bypass Pipe, these downpipes unlock even greater power potential by eliminating flow restrictions caused by catalytic converters. The result is a sharper throttle response, enhanced performance, and a more aggressive exhaust tone. Specifications - Pipe diameter (inches): 3.7 - Feature 1: 3.7'' ID Turbo Outlet to 3.15'' Downpipe with Decat/OPF Bypass - Feature 2: Fits with Milltek OPF/GPF Back System Only