*** NO LONGER AVAILABLE *** Bailey’s valves have a 60psi boost capability (most diaphragm valves fail around 30psi). All the benefits of the normal piston design, but with less audible ‘whoosh’. The DV30 was designed as a direct replacement for the factory fitted Bosch dump valve found on a wide variety of cars. The Bosch valve is made of plastic, contains a rubber diaphragm and is known to fail when subjected to too much boost pressure or excessive temperatures. The DV30 is the perfect choice for a standard car or fire-breathing 550+BHP tuned vehicle, capable of withstanding huge amounts of boost. As it is designed to direct the dumped boost back into the air filter or airstream, it is generally speaking ‘silent’ in operation.