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Catch can flow restriction

Posted: Tue Sep 11, 2018 12:31 pm
by rn240sx

So as you look at the black catch can above the fuel filter and to the left of the blue fuel press sensor, you see the left side of the catch can is the exit to a hose that runs under the car... no oil gets out because the catch can is oil separator ... to the right is the catch can inlet which i have a hose then to a 5/8 Y adaptor then the Y adaptor recieves crankcase pressure / blow by from the valve cover breather and the "modified" (straight thru fitting) pcv below, all hoses are 5/8 ... and all fittings are 5/8 ...
My question is do you think that Y adaptor poses any air flow restriction from the motor properly exhausting its crankcase pressure .... or do you think its ok ..??

Re: Catch can flow restriction

Posted: Thu Sep 13, 2018 7:06 am
by tuzzio
Start the car and put your hand over the PCV or VC breather. Ask your self if you really think that thing is restricting.

I don't believe so. A 5/8 line is a pretty good size line.

But geez, what a cluster ***** of awful looking hoses and fittings.

Re: Catch can flow restriction

Posted: Mon Sep 17, 2018 8:39 pm
by flip240
I also don't think there's much restriction, your setup should be fine. But I'm not a fan of vent to atmosphere PCV systems (but everyone does it), I'd rather see the PCV hooked up to the exhaust or intake to provide suction on the crankcase, but these are difficult to plumb imo.

Regardless, I also have my crankcase PCV changed to a striaght through fitting with a 3/8" hose going to a Evo PCV on a canister; the end goes back to an intake manifold vacuum source. My VC PCV goes to a canister then routed back to the intake before the turbo.

my semi-rigged setup