Supercharged ‘88 GT, closed PCV solution

[90sickfox]

That breather that lets air out is just like having a hose disconnected on the intake plenum. You can get rid of it all together. The problem is that system is supposed to stay sealed on the vacuum side.

The factory system has the fill neck hose hooked up to the intake pipe after the MAF. This allows the engine to pull vapors into the throttle body when accelerating. Under those conditions there is no vacuum so the PCV is closed. When cruising or idling the intake produces vacuum opening the PCV and pulling vapors.

In your application that routing is correct. It should go to the inlet pipe for the SC. There is no need for a check valve there because it won't see boost or vacuum.

The Supra check valve is very popular with boosted cars. On my set up the breather tank won't allow boost to build on the crankcase.... just like your breather filter on the hose going to the power pipe before the SC.

My car uses a stand alone ECU that users speed density ( no MAF ). In a car with MAF ghe hose going to the inlet of the SC should go after the MAF in the charge pipe.....just like mine would go in my charge pipe. Putting it before the MAF will cause the car to think theres more fresh air being oulled in than it actually is. ( this can be changed with a tune though ). In that case that hose would have to be sealed and use a check valve to keep boost out of the crank case. I'm not a big fan of running a system that way. If a check valve fails.... bad things can happen.

 

[jjanik191]

Great info, thank you. At this point, simply answered, here’s what I want to know.... in a closed PCV system, does the use of any single breather ANYWHERE, as in my case of using a baffled one-way breather on the passenger side valve cover, cause a loss of boost ?? My breather lets pressure out, and closes off to not let air in... Yes or no?

 

[90sickfox]

No....if it doesn't have a hose to the intake plenum or charge pipe from SC it won't cause boost loss.

 

[Noobz347]

Crappy ring seal is what causes both, "boost loss" and excessive crank case pressure (the stuff you're trying to vent with one-way breathers).

 

[90sickfox]

Crappy ring seal is what causes both, "boost loss" and excessive crank case pressure (the stuff you're trying to vent with one-way breathers).

Agreed...

 

[jjanik191]

Question on the Oil fill neck hose: mine is routed from the neck to the power pipe after MAF, and before the blower. I’ve read contradicting info on its function in a supercharged setup- is it supposed to be bi-directional? I currently have a one-way check valve allowing pressure out of the neck, but stopping it from going in so as to overpressurize the crankcase etc... after the check valve I have a catch can- should I remove the check valve to allow it to be bi-directional? Why or why not?

 

[90sickfox]

If its mounted before the blower the gasses will only flower one way. There's no pressure in the pipe before the blower to push air through the house back into ther engine.

 

[jjanik191]

In my set up, with the hose connected after MAF and before the blower, does it need to operate bi-directionally meaning one way under acceleration/boost, then flow the other way at idle so as to work in conjunction with the whole PCV system etc? Being new to supercharging, I’m just trying to wrap my head around the functionality of all the 3/8 lines running here, there and everywhere

 

[90sickfox]

There are so many ways that people handle this. Some people are just happy running open breathers in the valve covers.

It should run the same way the dealer does it. The only addition would be a check valve in the pcv hose connected to the plenum.....or catch cans if needed.

 

[93SCGT]

Anyone still following this thread? Have a question.

 

[General karthief]

Anyone still following this thread? Have a question.

ask away, the members will get an 'alert' and may be able to help you. You could start a new thread but since you are running a v1

 

[TOOLOW91]

Anyone still following this thread? Have a question.

Maybe I can answer ? I vent to atomosphere though to a catch can

 

[TOOLOW91]

ask away, the members will get an 'alert' and may be able to help you. You could start a new thread but since you are running a v1

V1/2/3/7 all refers to the gear set in a Vortech blower as well as inducer and outlet size that’s all . Still same concept for all

@General karthief this is covered in the supercharged stickie as well

 

[elarm1]

Maybe I can answer ? I vent to atomosphere though to a catch can

Do you have a diagram of your system?

 

[TOOLOW91]

Do you have a diagram of your system?

Two 10 fittings off my valve covers to a Moroso can hidden in my fender . You can see them in th pic and then they into the strut tower

 

[elarm1]

How often do you dump the can? Do you have to valve covers bung welded? Do you run any type of PVC? @TOOLOW91

 

[TOOLOW91]

How often do you dump the can? Do you have to valve covers bung welded? Do you run any type of PVC? @TOOLOW91

No pcv . Whenever I think to do it honestly . It usually never has too much in it and it’s mostly condensation