[Spencer]

You have the basic understanding of it

First of all The wastegate its self is located on the inside of the turbo. The part that is usually referenced is "usually" a little can looking thing with a rod coming out of the center. This is known as the wastegate actuator. You can get a wastegate actuator that is separated but it isn't really necessary for what most of us are doing. The wastegate actuator does just that. It activates the wastegate in the turbo. I believe the stock WG for the subbys is 7psi? So what this means is it will take 7psi to open the WG in the turbo thus relieving pressure to slow the turbine and reduce psi.

After the wastegate is activated the turbine begins to lose pressure and slow down. This is where the BCS (boost control solenoid) or MBC (Manual boost controller) comes in. For example my car is tuned at 19psi so my MBC will allow 19 psi to be built up before releasing the excess to hold that pressure.

So now a common problem I see is people wondering why they cant get more then 8psi or so of boost. chances are they are running at wastegate pressure and are either missing there "pill" (a little metal piece that sits in one of the boost lines that controls the psi.) or there is something wrong with the BCS / MBC.

Now back to the turbo. The BPV / BOV is a bleeding system, it blows off excess pressure to avoid surge to the turbo or too much pressure. During a shift when you take away all the RPM's and pressure that is pushing through the turbo the compressed air needs somewhere to go besides back into the turbo. If it was to go back into the turbo it could essentially force the turbine to stop abruptly or even begin to spin backwards which is obviously not good. So to relieve the pressure the compressed air is "blown off" In our case it is recirculated back into the system. On other cars you will see it "blow off" to atmosphere that is what causes that pshhhht noise. Do not put a BOV on a subby the car is not designed for it. All of the air that is calculated through the MAF needs to stay in the system for proper function. I believe it is possible to get tuned for an atmospheric blow off but I wouldn't recommend it. Also on that note there really isn't any need to change the stock BPV on these cars unless you are planning on running over 23-25+psi. The stock one works just fine.