blow off valve [Archive] - Audi Forums

: blow off valve

10-20-2011, 10:07 PM
ok so i have an 03 audi a4 1.8t quattro and i want a bov. i heard they're bad for audi's and i was wondering if this was true?

10-23-2011, 11:01 AM
The turbo-based intake boost system needs some means of dissipating unnecessary boot pressure (such as when the throttle body is closed, like during shifts or deceleration); the boost needs an escape route. If the boost cannot escape during these times, it can back up and cause air-pressure shocks to the turbo.

The difference between the OEM diverter-valve (DV) and a blow-off valve (BOV) is that a Blow-Off Valve (BOV) performs the same task as a DV, but instead of returning the boosted air back into the intake, it vents it out of the intake system to the atmosphere.

Good luck!