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I am running 30psi on the factory PCV system with no issues.
As long as you are venting crank pressure to atmosphere you will have issues, crank pressure must be sucked out through vacuum or it gets to high, especially with forced induction engines. Some big old V8 blocks can get away with venting to atmosphere.
A catch can will not help vent crank pressure, it is a resistance in the path of air flow. Catch cans are designed to catch some of the oil carried in the crank gasses to reduce the amount going back into the engine.

You could by a PCV vacuum pump and two catch cans and vent crank pressure to atmosphere, if you buy quality parts and set it up properly it could perform as good as the factory PCV system did. This will cost over 300$, or you could reinstall the factory PCV system and put the money towards something else like brakes, suspension or swaybar upgrades...
 

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Discussion Starter · #3 ·
I am running 30psi on the factory PCV system with no issues.
As long as you are venting crank pressure to atmosphere you will have issues, crank pressure must be sucked out through vacuum or it gets to high, especially with forced induction engines. Some big old V8 blocks can get away with venting to atmosphere.
A catch can will not help vent crank pressure, it is a resistance in the path of air flow. Catch cans are designed to catch some of the oil carried in the crank gasses to reduce the amount going back into the engine.

You could by a PCV vacuum pump and two catch cans and vent crank pressure to atmosphere, if you buy quality parts and set it up properly it could perform as good as the factory PCV system did. This will cost over 300$, or you could reinstall the factory PCV system and put the money towards something else like brakes, suspension or swaybar upgrades...
Do you have any extra stock pvc system I can buy
 

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It's two pieces of hove and a 4$ valve available at any parts store.
What else are you missing? what are you using for your intake pipe between the air filter and turbo?
 

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Picture 1: Between the timing belt and oil cap, insert PCV valve, run 3/8" hose from the valve to the port on the intake manifold that's blocked with hose and a bolt.
Picture 2: Have a 3/8" barbed fitting installed in the black pipe right after the air flow meter, you can have it welded or threaded into the pipe using 1/4" or 3/8" NPT male thread on a 3/8" barbed fitting, connect the hose leaving the valve cover above the mazda badge to the 3/8" barbed fitting that you had installed on the black inlet pipe.

Automotive exhaust Automotive air manifold Gas Auto part Muffler


Above you can see the NPT/Barbed fitting (with yellow plastic ring) for the PCV system.

Motor vehicle Automotive design Automotive air manifold Car Auto part


This barbed fitting was threaded through very thin aluminum so I used a longer thick coupling and threaded through that also.

Wood Bumper Tints and shades Hardwood Bicycle part


This is the air filter to turbo pipe for the current 626GT, the large port is for the re circulation valve (BPV), the barbed fitting is for boost controller return air and the small black fitting is for the PCV.
 

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You do need to run the vacuum and the PCV for the catch can Just put the catch can between the PCV valve and the intake manifold, when I get home from work I will add a photo of what I did.
 
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