[BiturboS4] BOV v. DV

Todd Sager todd at awe-tuning.com
Fri Jul 19 11:05:41 EDT 2002

A BOV vents boost between shifts and at part throttle to the atmosphere,
hence the "whoosh" noise you hear from a car equipped with one.

A DV vents the boost back to the intake side of the turbo.

A DV is required on a Mass Air Flow (MAF) equipped car to prevent the
ECU from incorrectly adapting the fueling.  With a BOV, the ECU sees air
being pulled through the MAF, and assumes this air is being used by the
engine, when in fact it is being vented to atmosphere.  This leads the
ECU to add fuel unneccessarily, which begins to degrade drivability.

California Fields wrote:
> [ Converted text/html to text/plain ]
> Can someone explain to me the difference between a blow-off valve (BOV) and a
> diverter valve (DV)? Also, are these things that you all recommend replacing
> with aftermarket parts on the S4?  Forgive me if these answers were already
> present in any FAQ...I didn't know where it was located.
> Thanks much, Carter.


As of July 8, 2002, AWE Tuning has moved to a new, state-of-the-art

2385-C Maryland Rd
Willow Grove, PA  19090

Please direct all shipments and correspondence to this new address.

If you have any questions, please do not hesitate to contact us.

A.W.E. Tuning
Orderline 888-565-2257

More information about the Biturbos4 mailing list