the top of my greddy type S bov says "soft" "hard" with arrows and an allen head screw. what does this do?


2nd Q-
Most of the turbo motors I have seen use a small filter on the front crankcase breather hole instead of running a tube to the intake. Is this just a function of not having a good place to run a hose to or is there some other advantage I am not aware of?

3rd.
The oil catch can that attaches to the pcv valve is run back to the manifold becuase vacuum is what opens the valve right? Is there going to be an adverse affect of have a positive load run back into the pcv when I am under boost?


thanks,
alex

 

1. Don't know.

2. In case oil vapours come out that breather, you don't feed it back into the intake.

3. The PCV valve is a one way valve. Manifold pressure keeps it closed. Manifold vacuum opens it.

 

thanks Xviper.

now just one question.

 

1. It's the tension of the spring. If you set it to HARD it takes more pressure/vacuum to open it. As we want the BOV open all the time except WOT you should set it more on the SOFT side.

2. It's an emissions thing. Oily vapour is fed back into the intake tract and hopefully burnt. Considering your other thread about the oil in you BOV I suspect if you use a filter it will clog up with oil in no time.

3. ALthought he PCV wasn't designed for positive pressure I suspect with the low boost we are using it wouldn't be a problem so long as your PCV is working correctly.

 

thanks guys