PCV Turbo Venting!
I'm bringing this post back from the dead because I have a question about 2002ws-6's PCV system. I understand how it works and it looks like a good setup.
I have one question about it though. On his first pic I can see where he is drawing in fresh air into the PCV, but on the second pic the check valves look like they close any route to incoming fresh air. It seems like the crank case is being vented, but no fresh air is going back in. Maybe there's enough pressure built from blowby and fresh air does not need to enter while under boost, or maybe I'm not seeing something obvious. Can someone please explain?
I'm just trying to better understand PCVs and FI.
I have one question about it though. On his first pic I can see where he is drawing in fresh air into the PCV, but on the second pic the check valves look like they close any route to incoming fresh air. It seems like the crank case is being vented, but no fresh air is going back in. Maybe there's enough pressure built from blowby and fresh air does not need to enter while under boost, or maybe I'm not seeing something obvious. Can someone please explain?
I'm just trying to better understand PCVs and FI.
you got it dead on, under boost any crankcase gases built up are what is being vented. No need for fresh air while boosting. It acts just like a car with a couple of breather filters on it.
Originally Posted by 2002ws-6
you got it dead on, under boost any crankcase gases built up are what is being vented. No need for fresh air while boosting. It acts just like a car with a couple of breather filters on it.
Is your pcv set up the same as EGash's first diagram?
If I have a blower would you set it up differently?
TECH Enthusiast
Joined: Jan 2004
Posts: 608
Likes: 0
From: New Zealand
I like the look of this setup (top pic),
does it still use the factory PCV valve as well as the two check valves ?
Was thinking maybe a second unvented catch can in the line to inlet manifold to ruduce any oil vapour entering manifold .
there are 3 parts to my pcv system
line from intake to valve cover(or crankcase) w/ 1 way valve and oil separator
this is a vacuum source to pull air (and a slight vacuum) through the engine when out of boost, and seal when in boost
line from valley cover (or crank case)to in front of turbo/(sc)
this is a vacuum source to pull air through the engine when in boost (low presssure area btwn air filter and turbo/(sc)) and a fresh air source when out of boost (see above)
large home made 1 way valve on valvecover (or crank case)
this allows any positive pressure that may develop to escape quickly and easily
line from intake to valve cover(or crankcase) w/ 1 way valve and oil separator
this is a vacuum source to pull air (and a slight vacuum) through the engine when out of boost, and seal when in boost
line from valley cover (or crank case)to in front of turbo/(sc)
this is a vacuum source to pull air through the engine when in boost (low presssure area btwn air filter and turbo/(sc)) and a fresh air source when out of boost (see above)
large home made 1 way valve on valvecover (or crank case)
this allows any positive pressure that may develop to escape quickly and easily
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Verdad Gallardo 2002ws-6,
I've read on some posts that the vented catch cans are a vacuum leak and you should use a non-vented can. I see a lot of vented catch cans running without any problems though. Have you had any problems?
I see that you are not venting or pulling in any fresh air anywhere else, so I guess you need it.
I've read on some posts that the vented catch cans are a vacuum leak and you should use a non-vented can. I see a lot of vented catch cans running without any problems though. Have you had any problems?
I see that you are not venting or pulling in any fresh air anywhere else, so I guess you need it.
Originally Posted by MIGHTYMOUSE
there are 3 parts to my pcv system
line from intake to valve cover(or crankcase) w/ 1 way valve and oil separator
this is a vacuum source to pull air (and a slight vacuum) through the engine when out of boost, and seal when in boost
line from valley cover (or crank case)to in front of turbo/(sc)
this is a vacuum source to pull air through the engine when in boost (low presssure area btwn air filter and turbo/(sc)) and a fresh air source when out of boost (see above)
large home made 1 way valve on valvecover (or crank case)
this allows any positive pressure that may develop to escape quickly and easily
line from intake to valve cover(or crankcase) w/ 1 way valve and oil separator
this is a vacuum source to pull air (and a slight vacuum) through the engine when out of boost, and seal when in boost
line from valley cover (or crank case)to in front of turbo/(sc)
this is a vacuum source to pull air through the engine when in boost (low presssure area btwn air filter and turbo/(sc)) and a fresh air source when out of boost (see above)
large home made 1 way valve on valvecover (or crank case)
this allows any positive pressure that may develop to escape quickly and easily
This may make a diff, but my car is runnig an SD 2bar tune. The maf is not providing any numbers for the ECU calc's. I've had no problems at all. The car runs completely normal while not boosting, and it acts like a 1950's car before PCV was even invented while boosting. I can check my old PM's cause I gave the Check Valve part number to somebody. Here is it
Vw/Audi part number 078 905 291 B $18.50 retail
Vw/Audi part number 078 905 291 B $18.50 retail
can someone tell me if this will work?i like $1 a piece vs $16 a piece
http://www.usplastic.com/catalog/pr...duct%5Fid=15641
http://www.usplastic.com/catalog/pr...duct%5Fid=15641
Launching!
Joined: Feb 2007
Posts: 297
Likes: 0
From: Tucson
guys looking for check valves
I fabed a custom gas tank once and needed a check valve
like a one way vented gas cap any way
heres what to do :
get the summit or jegs fuel tank rollover check valve
take the an6 or an8 piece off the will be a steele in there.
go to ace hardware get a spring (pusher style) maybe get a couple on strenghs , based on boost levels, reassemble with spring pushing the ball agianst the seat inside
you have a check valve
I fabed a custom gas tank once and needed a check valve
like a one way vented gas cap any way
heres what to do :
get the summit or jegs fuel tank rollover check valve
take the an6 or an8 piece off the will be a steele in there.
go to ace hardware get a spring (pusher style) maybe get a couple on strenghs , based on boost levels, reassemble with spring pushing the ball agianst the seat inside
you have a check valve 
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Originally Posted by WicketMike
why not just block off the line from the intake and the throttlebody and just run a catch can from the lines from the valve covers without any check valves ?
because that would be far too easy
Originally Posted by ddnspider
can someone tell me if this will work?i like $1 a piece vs $16 a piece
http://www.usplastic.com/catalog/pr...duct%5Fid=15641
http://www.usplastic.com/catalog/pr...duct%5Fid=15641
Originally Posted by WicketMike
why not just block off the line from the intake and the throttlebody and just run a catch can from the lines from the valve covers without any check valves ?
Originally Posted by stevieturbo
because that would be far too easy
thats what i ended up doing about a month ago, seemed alot easier and less to deal with