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Discussion Starter #1
I have a 94 gt with an on3 kit, want to delete pvc and run a catch can due to u metered air entering. If i delete my pcv will i have vacuum issues? Kind of a Noobie to the turbo game
 

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Remove pcv and obviously cap where it connects to the intake manifold. What I did was run a hose from the pcv port to the catch can and another from the oil fill cap to the catch can. This will not cause any vacuum leaks, I don't know what kind of shape the rest of your lines at in though
 

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Why do you want to delete the PCV system??:frown2:

It performs very useful functions if you want your engine and oil to last longer!!:wink2:
 

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Why do you want to delete the PCV system??:frown2:

It performs very useful functions if you want your engine and oil to last longer!!:wink2:
Because when you get up into Race Car status, its pointless to even mess with. Just vent the crankcase to a properly sized breather, and change the oil on time.
 

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A check valve inline will stop the pcv from letting pressure into the crankcase under boost. Some pcv's hold and some don't. The tube that runs from the TB to the oil fill tube will do it also. On my friends 91 we made a check valve and put inline with pcv and removed the line from TB to fill tube, capped it at TB and used a clamp on filter at fill tube. This stopped his issues.
 

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Discussion Starter #6
Im not worried about air into the crankcase, im worried about it sucking unmetered air from the crankcase being overpressurized and going into intake downstrwam from the mass air meter causing a slight lean condition.
 

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Im not worried about air into the crankcase, im worried about it sucking unmetered air from the crankcase being overpressurized and going into intake downstrwam from the mass air meter causing a slight lean condition.
The stock is set up for the pcv, with no vacuum in intake you have no unmetered air causing lean condition. You should worry about pressure in crankcase, it will leak oil under boost. Blowby and boost will make one leak that normally doesn't.
At idle and cruise conditions the O2 will tell the ecm if it needs to add/subtract fuel.
On my Turbo Buick I had to use a check valve cause I couldn't find a pcv that sealed good under boost and also had to restrict the vac signal because it was sucking oil off the valley pan. Blocking it off screwed up idling. My DD 90 GT pcv stopped up and idled like crap and low speed driving sucked too. Change pcv with new Motorcraft and all is good.
 

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A check valve inline will stop the pcv from letting pressure into the crankcase under boost. Some pcv's hold and some don't. The tube that runs from the TB to the oil fill tube will do it also. On my friends 91 we made a check valve and put inline with pcv and removed the line from TB to fill tube, capped it at TB and used a clamp on filter at fill tube. This stopped his issues.
Going this route, you have a vacuum leak of unmetered air entering the intake through that clamp on filter.
 

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Only at idle and light throttle. Might mike a slight difference, nothing noticable. I have had cars done both ways with no issues. At any rate I wouldn't eliminate the pcv on a street car.
 
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