Some car tuners consider the sound of a blow off valves to be desirable, and may wish to swap their DV/PBV with BOV.

First a brief explanation on what these valves are, and what they do.

Blow-Off ValveBlow Off Valve (BOV)

Releases excess exhaust pressure from turbo charging system to atmosphere. Creates a 'whoosh' noise.

Diverter ValveDiverter Valve (DV) or By-Pass Valve (BPV)

Re-circulates excess exhaust pressure into turbo charging system. Relatively silent when working.

If your turbo system is engineered to utilize a DV/BPV, you may be able to safely switch to BOVs. This depends on the location of the DV/BPV in relation to the Mass Air Flow sensor (MAF) in the boost charging/intake system.

If the DV/BPV is located after the MAF, don't do it.

This means that the amount of air which passes the DV/BPV has been metered and communicated to the ECU. The ECU then determines the amount of fuel to supply based on the air reading.

In this scenario, the metered air is subject to being dumped by the blow off valve, thus altering the air-fuel ratio with excess fuel. This term is referred to as 'running rich'. This excess fuel in your cylinders can eventually eat away at piston rings and cause 'blow by' (lowered compression).

If the DV/BPV is located before the MAF, go for it.