View Full Version : Blow Off Valves
06-02-2004, 09:33 PM
i know that a BOV lets off compressed air when the throtles are snaped shut but, how do they know when to open up. and they have a cord kind of thing coming out of the end, whats this for?
06-03-2004, 07:57 AM
Blow-off valves are vacuum-actuated. It is designed to release pressure from the intake tract of a turbo when the throttle closes. It releases the pressured air into the atmospherere whils making a loud 'hhhssss' sound. Another device would be a compressor bypass valves which does the same thing but they circulate the air back into the intake before the turbo inlet.
06-03-2004, 01:22 PM
also pop off valves do the same thing but at a predeturmined pressure, same effect different method, also not all bov's create that sound, most of them are engineered in to anounce the presence of a turbo, but this sound also decreases their effectivness becouse the sound indicates there is a restriction so the bov isnt venting as fast as it could be.