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Valsti05
Our cars are designed to use a recirculating BPV because of the position of the BPV vs. MAF. The MAF is at the beginning of the intake track and the BPV is sandwiched in the middle. The MAF measures the air incoming into the system. The factory BPV recirculates the metered air back through the system when the throttle is lifted and the engine pulls vacuum.
The reason for not using a vent to atmosphere valve is that your releasing the metered air, as measured by the MAF, to the atmosphere and not back through the system. The system thinks there is that air there and has adjusted fueling for that. The engine can run momentarily rich, sputter and even in extreme cases idle erratically or even die, especially at sudden throttle lift.
What in essence you create by adding a VTA BOV is vacuum/boost leak.
The factory BPV is quite capable of holding boost and can be audible if you do a silencer delete. Of course a CAI will make it more loud, with a tune, of course.