Honda D Series Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
234 Posts
Discussion Starter #1 (Edited)
Just trying to make this function better with what Ive got.
This is on my turbo civic.
Previous owner has the 'vent' (shown below) connected to the black box (see second picture)





The PCV valve is also still hooked up normally. This seems completely pointless to me. The valve cover vent has the usual filter on it.

I cant seem to think straight and figure out someway this will do something or how to set it up where it will.

Gonna try to scour more PCV threads for ideas. Itd be great if anyone can shed some light on this for me.

Also, where the vent is connected on the black box, is that a normal outlet, or was that 'custom'?
 

·
Registered
Joined
·
234 Posts
Discussion Starter #3
Stock NA car the black box should go to a pcv and then to the intake manifold.
The valve cover vent should be hook to the intake tube. On oem there is a cut tube so that air goes into the valve cover.
I shouldve mentioned this is on my boosted civic, sorry.
 

·
Registered
Joined
·
234 Posts
Discussion Starter #4
Im thinking PCV valve gets ditched and I run a simple check valve from the intake to the breather box and leave the valve cover vent without a filter.
This way under vacuum the crankcase is under somewhat of a vacuum, but when check valve closes it still has the valve cover vent and the breather line from the black box to vent.
 

·
Registered
ej8
Joined
·
6,365 Posts
I shouldve mentioned this is on my boosted civic, sorry.
Then vent both lines.
The black box should be vented to a hose without the pcv,
And the valve cover vented also.

You can get a catch can and make all this look nice and also hook up a port on the can to the intake of the turbo to help suck out the blowby but that can get messy and send oil into the turbo and intercooler looking.

But look up turbo catch can civic.
 

·
Registered
Joined
·
234 Posts
Discussion Starter #6
Well, removed the pcv valve and it changed a few things.

Turbine whistle seems to be louder, spool is much more linear and its smoking more under deceleration.

Also it's pulling less vacuum under the same amount of throttle as before.
 

·
Registered
ej8
Joined
·
6,365 Posts
Well, removed the pcv valve and it changed a few things.

Turbine whistle seems to be louder, spool is much more linear and its smoking more under deceleration.

Also it's pulling less vacuum under the same amount of throttle as before.
idle vac should not have change unless you undid a vacuum hose.
Now throttle vac should go to 0ingh faster because the turbo is spooling mor.
About it smoking more im not 100% sure on that. Venting the crank should let out all the pressure build up.
 

·
the artist formerly known as drexelstudent11
Joined
·
3,983 Posts
the way you have it now, open VC breather and open black box breather, while not environmentally friendly, is optimal. that's two places the crankcase pressure can escape from under boost.

as for the smoking under deceleration, how are your valve guides/seals looking?
 

·
Registered
Joined
·
17 Posts
Typically you want to hook a catch can, mounted in as low and cool of place as you can find, to the VC then a hose going to the pre-turbo intake. With everything just vented to atmosphere the crankcase does not pull vacuum which makes it more difficult for the valve seals to seal, which can cause some smoke on deceleration . The idea of mounting the catch can in a lower and cooler place with baffling is so that the blow-by will cool down and settle in the can, you still suck some vapor through the turbo, but it shouldn't get messy.
 

·
Meat Popsicle
91 CRX Si
Joined
·
2,931 Posts
Vent the valve cover and black box to a vented catch can. No PCV valve.

That is the right way to do it for a turbo setup unless you're bound by strict emissions/inspection laws

The additonal blowby from increased cylinder pressures makes the absense of vacuum in the crankcase less necessary. Emissions will suffer since you're venting hydrocarbons to the atmosphere and your oil may be more saturated with hydrocarbons but the absense of them in the intake charge usually outweighs these points
 

·
Registered
Joined
·
234 Posts
Discussion Starter #12
Im going to vent the line coming from the black box to atmosphere, run the valve cover breather tube to pre turbo, the filter I have happens to have a hose barb fit onto it and run a check valve from intake to breather box.
 

·
the artist formerly known as drexelstudent11
Joined
·
3,983 Posts
Im going to vent the line coming from the black box to atmosphere, run the valve cover breather tube to pre turbo, the filter I have happens to have a hose barb fit onto it and run a check valve from intake to breather box.
that'll work too but it will spray that shit all over your turbo/IC pipes
 

·
Meat Popsicle
91 CRX Si
Joined
·
2,931 Posts
I guess you're not at all worried about sucking dust particles getting in through the black box.

Also, if you plan on doing any kind of sanctioned racing that requires a tech inspection, you cannot vent to atmosphere in that manner
 
1 - 15 of 15 Posts
Top