The heart of any Turbo system is the Manifold and the Turbocharger. These form the basis where the rest of the turbo system is built around. Turbo manifolds have only one, but the most critical purpose in turbo systems, and that purpose is to expel exhaust gas into the turbine of a turbocharger as efficiently as possible. There is no match for power and performance for tubular stainless steel manifolds. Tubular manifolds are made up of runners coming from each cylinder, meeting up at a collector. Tubular manifolds yield a higher efficiency rate, as each runner is generally the same circumference. This tubular manifold furthers the even exhaust flow using "equal length" runners. Equal length tubular manifolds are the most efficient design, which ensures equivalent air flow rate smoothly from each cylinder. This allows for a much smoother flow of exhaust gas to the turbo. Tubular stainless steel manifolds are chosen over cast manifolds for big power applications. Tubular stainless manifolds feature better and more consistent flow of exhaust gases. Most of the tubular Stainless manifolds also feature the placement of the waste gate flange towards the middle of the collector to allow accurate readings and precise control. Replace for 97-06 Audi / VW 1. 8L Turbo Engines Does not Fit Stock Turbos