[BiturboS4] BOV v. DV

[Ian McCloghrie]

On Jul 19, 2002 john sonty wrote:
> Not only that, but it'd seem that with a BOV, the whole system
> would have to start building boost from scratch after a shift,
> no??

Not really.  With a BOV or DV, the compressor is allowed to keep
freewheeling, so that as soon as the valve closes it repressurizes the
intake tract.  Without such a valve, the closed throttle plate causes
a huge build-up of air, which stalls the compressor wheel.  The turbo
essentially stops spinning, meaning that you have to spool it back up
again when the throttle reopens.  This stall can also, in some cases,
damage the compressor.

--Ian