The factory valves are prone to leaking pressure under increased boost when the car has an upgraded ECU flash. As well, the factory Bosch valves will taper boost off with the diaphragm design even at stock boost levels. To help keep the boost pressure constant all the way to redline, upgrading the stock diverter valves to the Agency Power Racing Diverter Valve Kit will improve your cars overall performance. The Agency Power Diverter Valves are sold as individual units for all the Volkswagen and Audi turbocharged vehicles. These will fit the 1.8T and even the 2.7T motors. These valves are CNC machined 6061 aluminum which have been precision engineered to fit with the stock or aftermarket F-Hose and intake return hoses. The internal construction of the valve uses a machined piston with proper o-rings to ensure a smooth motion that is air tight to prevent any boost leaks. The spring has been engineered to hold moderate to aggressive boost increases on your turbo car. The valves feature a 90 degree removable swivel connection for easy fitting with the factory vacuum hose. If needed, the top of the valve unscrews allowing you to re-greased and service the valve. Valves are available in a polished finish and feature the Agency Power text and logo laser engraved on the top. As tested, these valves are a great upgrade for stock turbos or even cars with larger turbo kits. Valves are sold individually and are available in Black