Ferocity02

iTrader: (60)

I'm looking for a valve that is preferably vacuum operated, that has three ports, A, B, and C for example. When the valve is "open" flow can go between A and B. And when the valve is "closed" flow can go between A and C. The valve would be open in vacuum or anything below ambient pressure, and closed in boost. It could be electrically actuated too and I can use a hobbs switch to control it, but I prefer if it's vacuum operated as that will make it simpler to setup.

If you're wondering why I'm looking for this, I am trying to make a PCV system that works like stock in vacuum when keeping the MAF sensor on a turbo setup. The idea is that ANY air the motor is ingesting must pass through the MAF sensor. At least this is what my tuner says. Otherwise its just a big vacuum leak.

This valve would connect as follows using the example lettering form above...
A = valve cover PCV port
B = throttle body PCV port
C = to atmosphere or to turbo inlet

When the valve is open in vacuum, flow can go from the TB (B) to the valve cover (A) to vent the motor through the PCV system. When the valve is closed in boost, the flow would go from the valve cover (A) to the atmosphere or the turbo inlet (C) to let blowby out of the motor.

Right now I'm running a breather on the passenger side and I have the PCV line going to the turbo inlet through a catch can. But there isn't enough vacuum in the turbo inlet to do any good, so the smoke is just coming out of the breather, and it doesn't smell that great.

This is more for fun and to experiment, so hold off on the flaming and the diagrams of your PCV system, I've seen them all. But if you see an issue with this idea let me know.

So does anyone know where to find said valve? I thinking they had to have come stock on some cars, especially ones turbo'd from the factory that have extravagant PCV systems.

Sarg

iTrader: (6)

Gm boost control solenoid.

Ferocity02

iTrader: (60)

Thanks for the tip! The ports on that look pretty small. I'm thinking I'll need 3/8-1/2". I found these things called diverter valves that might work, but I've never held one to see how it functions. A heater bypass valve might also work, same issue though, I've never played with one.

Sarg

iTrader: (6)

Why not just 2 check valves and a T fitting?

Ferocity02

iTrader: (60)

One reason is the pressures involved (pressure inside the block cause by blowby or vacuum inside the block cause by the PCV) are pretty small, so a check valve might cause issues. The other reason I don't think two check valves will work for what I want to accomplish.