Does anyone know if these things come with a stock blowoff valve? At times it sounds like there is one but not for sure and i havent been able to find much about it......

 

no the engine is internaly wastegated.

 

BOV or blow off valve is for the inlet side pressure relief when you let off the throttle while under boost, to help protect the turbo from undue loads. I believe the SS has a vent or blow off that goes back to the intake before the turbo but after the mass air sensor, so as to not disrupt the calibration of air to fuel, if you dumped it externally, the mass air would still be reading high air flow, and would be adding fuel for air that actually was venting out the BOV, and the engine would go rich. There is some noise associated with it, but not like an external venting BOV.

The wastegate is the turbo pressure control, and is the limiting device for boost.

 

I'm subject to road rage so a BOV is very helpful for me.

 

They have a diverter valve. That does not release the pressure, but recirculates it. I don't see why a BOV couldn't be applied in this situation, just give it a little while for someone to develop one specifically, or you can get a universal BOV.

 

The diverter does release the pressure that is after the turbo, to the inlet side. That takes the load off the turbo and keeps it from surging, which happens when the air "stalls" in the turbo. That is hard on turbo bearings. It is the same principal used in large turbine air compressors.
The reason GM did it that ways is explained in my post above. The Mass air sensor cannot know how much air you release to the outside, so it adds fuel to match ALL the air that went thru the Mass Air sensor. If you vent a good bit of that air to the outside, then the engine still gets the fuel that would have been used for that air, and the engine is then rich, bad for emissions, bad for catalytic converters that have to burn the excess fuel.

Not saying you can't use an external BOV, but the factory setup is a pretty clean way of doing it, don't you think?

 

Yes, and who really needs the loose ass fart sound between gears anyways?

 

not if you get a decent one

 

Sounds like you have a surge valve and not a real bov. You guys really start upping the boost and eventually you'll want a real bov. On my car you start spiking 20+ the stock surge valve can start leaking. I don't know about your cars, though. Nobody as yet has played with a lot more power.

 

I don't have one yet, but my buddy has one on his STi and it sounds good... not like a loose fart...