Turbo pcv routing options?
Turbo pcv routing options? Well I hope I’m not pestering you guys. I do a web search before posting but didn’t find the exact answer I was looking for. Also so many conflicting opinions. So....
what i have now is a vacuum line from my intake to my catch can then my catch can to the valley cover. (Ls1). Then I have a line that goes from my valve cover to the throttle body on the intake manifold side of the throttle blade. So I guess that sees vacuum too. I’ll include a visual down below.
My question is, can I cap the line going to the intake from the catch can and reroute that hose over to the intake side of my turbo (non boost of course). Then cap the valve cover tube going to the throttle body and plug the port on the throttle body and then add a breather to the valve cover where my oil cap would go. Would that work, or cause me issues? Should I maybe leave the line from the throttle body to the valve cover but put a check valve in? Still do the breather? I don’t want to smell oil, spit oil out the exhaust or contaminate my turbo with oil. My thought process is the catch can would catch the oil before going into the turbo? I could alternatively hook the catch can pipe to my exhaust down pipe and a 45 degree angle and use that for suction. Just a little in the fence as to what I should do. Thanks in advance fellas!
what i have now is a vacuum line from my intake to my catch can then my catch can to the valley cover. (Ls1). Then I have a line that goes from my valve cover to the throttle body on the intake manifold side of the throttle blade. So I guess that sees vacuum too. I’ll include a visual down below.
My question is, can I cap the line going to the intake from the catch can and reroute that hose over to the intake side of my turbo (non boost of course). Then cap the valve cover tube going to the throttle body and plug the port on the throttle body and then add a breather to the valve cover where my oil cap would go. Would that work, or cause me issues? Should I maybe leave the line from the throttle body to the valve cover but put a check valve in? Still do the breather? I don’t want to smell oil, spit oil out the exhaust or contaminate my turbo with oil. My thought process is the catch can would catch the oil before going into the turbo? I could alternatively hook the catch can pipe to my exhaust down pipe and a 45 degree angle and use that for suction. Just a little in the fence as to what I should do. Thanks in advance fellas!
Launching!
Joined: Jan 2018
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turbo LSx really need to breathe, especially turbo ones.
I would suggest blocking both the valley cover and TB ports. run a -10 minimum hose from each cover to a catch can vented to atmosphere. don't shove it back into the turbo intake.
I would suggest blocking both the valley cover and TB ports. run a -10 minimum hose from each cover to a catch can vented to atmosphere. don't shove it back into the turbo intake.
Nobody has replied because this is a loaded topic since there are so many ways to skin it.
Your can is not vented so the can will need to see vacuum and have a check valve to keep from pressurizing the crank case when under boost, you'll also need to vent the crank case sufficiently (breathers on valve covers, etc.) Also make sure that the breather is on the opposite side of the engine that vacuum draws from.
Intake vacuum to can - can to valve and or valley cover - breather on opposite valve cover or both if needed.
Cans like the Mighty Mouse can actually filter the air on the vacuum side and the exhaust side so you don't get the oil smell and residue like you will with a breather mounted on the valve cover.
Some guys also just put a breather on each valve cover and run no system at all.
I personally run the Mighty Mouse can and it has performed well for me, my car is a driver so no smell or residue was important for me and the MM can does both. After upping the boost on my combination I had to run larger lines to keep from popping my dipstick out and spraying oil everywhere so make sure you do it right or you will have problems down the road.
Hope this info was helpful.
Your can is not vented so the can will need to see vacuum and have a check valve to keep from pressurizing the crank case when under boost, you'll also need to vent the crank case sufficiently (breathers on valve covers, etc.) Also make sure that the breather is on the opposite side of the engine that vacuum draws from.
Intake vacuum to can - can to valve and or valley cover - breather on opposite valve cover or both if needed.
Cans like the Mighty Mouse can actually filter the air on the vacuum side and the exhaust side so you don't get the oil smell and residue like you will with a breather mounted on the valve cover.
Some guys also just put a breather on each valve cover and run no system at all.
I personally run the Mighty Mouse can and it has performed well for me, my car is a driver so no smell or residue was important for me and the MM can does both. After upping the boost on my combination I had to run larger lines to keep from popping my dipstick out and spraying oil everywhere so make sure you do it right or you will have problems down the road.
Hope this info was helpful.
Nobody has replied because this is a loaded topic since there are so many ways to skin it.
Your can is not vented so the can will need to see vacuum and have a check valve to keep from pressurizing the crank case when under boost, you'll also need to vent the crank case sufficiently (breathers on valve covers, etc.) Also make sure that the breather is on the opposite side of the engine that vacuum draws from.
Intake vacuum to can - can to valve and or valley cover - breather on opposite valve cover or both if needed.
Cans like the Mighty Mouse can actually filter the air on the vacuum side and the exhaust side so you don't get the oil smell and residue like you will with a breather mounted on the valve cover.
Some guys also just put a breather on each valve cover and run no system at all.
I personally run the Mighty Mouse can and it has performed well for me, my car is a driver so no smell or residue was important for me and the MM can does both. After upping the boost on my combination I had to run larger lines to keep from popping my dipstick out and spraying oil everywhere so make sure you do it right or you will have problems down the road.
Hope this info was helpful.
Your can is not vented so the can will need to see vacuum and have a check valve to keep from pressurizing the crank case when under boost, you'll also need to vent the crank case sufficiently (breathers on valve covers, etc.) Also make sure that the breather is on the opposite side of the engine that vacuum draws from.
Intake vacuum to can - can to valve and or valley cover - breather on opposite valve cover or both if needed.
Cans like the Mighty Mouse can actually filter the air on the vacuum side and the exhaust side so you don't get the oil smell and residue like you will with a breather mounted on the valve cover.
Some guys also just put a breather on each valve cover and run no system at all.
I personally run the Mighty Mouse can and it has performed well for me, my car is a driver so no smell or residue was important for me and the MM can does both. After upping the boost on my combination I had to run larger lines to keep from popping my dipstick out and spraying oil everywhere so make sure you do it right or you will have problems down the road.
Hope this info was helpful.
Ok guys I wanted to update what I did and what I’ve figured out.
First off i capped off all my vaccum lines to my manifold that go to my crankcase. I figured out whoever had the car before me hooked up the catch can wrong too. I machined a hole in the top of my catch can for a pop in filet and added another fitting to the can and hooked those cent lines to the passenger side valve cover and the valley cover. Basically just allow the crankcase to breathe in its own. Not the best or most ideal thing to do in my opinion. It will likely work but I think I’m going to do something else. Something I feel would be better. I work at a dealership and I had one of our factory turbo cars in the shop. I looked how the factory did it, they have a 3/8 hose going from the valve cover to engine vaccum, Check valve in the valve cover. Then they have a 3/4” hose hose going from the other side of the valve cover, baffled I’m sure, to the intake filter side of the turbo. My therory is the vacuum takes care of evacuation at idle and low loads and higher loads the larger hose takes over. What do you guys think of that? I may try to duplicate it.
First off i capped off all my vaccum lines to my manifold that go to my crankcase. I figured out whoever had the car before me hooked up the catch can wrong too. I machined a hole in the top of my catch can for a pop in filet and added another fitting to the can and hooked those cent lines to the passenger side valve cover and the valley cover. Basically just allow the crankcase to breathe in its own. Not the best or most ideal thing to do in my opinion. It will likely work but I think I’m going to do something else. Something I feel would be better. I work at a dealership and I had one of our factory turbo cars in the shop. I looked how the factory did it, they have a 3/8 hose going from the valve cover to engine vaccum, Check valve in the valve cover. Then they have a 3/4” hose hose going from the other side of the valve cover, baffled I’m sure, to the intake filter side of the turbo. My therory is the vacuum takes care of evacuation at idle and low loads and higher loads the larger hose takes over. What do you guys think of that? I may try to duplicate it.
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not the best picture but here's how i do it. Car is blown but whatever, same ****. The car is speed density and maf so i have the pcv valve in my driver side valve cover, line comes into the catch can and the outlet goes to its normal location with a check valve placed between the can and the intake. My oil cap is replaced with a cfm breather (built in check valve, only opens with excessive crankcase pressure) and then i have my breather line that normally goes to the to the tb running down to the inlet side of the blower between the inlet and maf. The other rear nipple on the passanger side vc is capped and so is the tb.
when i didnt have the breather nipple running to the inlet side, i used to get pressure push past my valve seals and got some smoke after a hard pull and returning to idle. Now i just consider the cfm breather a fail safe to vent extra pressure if the little breather line gets overwhelmed.
The hose from the VC to filter supplies filtered air to the crankcase, which is sucked thru the engine by the
hose from the other VC to the TB. I just run a hose from the DS VC, to a ck valve, to a small oil sep, then to
the VC. Diff ways to get to the same place, lol.
hose from the other VC to the TB. I just run a hose from the DS VC, to a ck valve, to a small oil sep, then to
the VC. Diff ways to get to the same place, lol.
Ok guys I wanted to update what I did and what I’ve figured out.
First off i capped off all my vaccum lines to my manifold that go to my crankcase. I figured out whoever had the car before me hooked up the catch can wrong too. I machined a hole in the top of my catch can for a pop in filet and added another fitting to the can and hooked those cent lines to the passenger side valve cover and the valley cover. Basically just allow the crankcase to breathe in its own. Not the best or most ideal thing to do in my opinion. It will likely work but I think I’m going to do something else. Something I feel would be better. I work at a dealership and I had one of our factory turbo cars in the shop. I looked how the factory did it, they have a 3/8 hose going from the valve cover to engine vaccum, Check valve in the valve cover. Then they have a 3/4” hose hose going from the other side of the valve cover, baffled I’m sure, to the intake filter side of the turbo. My therory is the vacuum takes care of evacuation at idle and low loads and higher loads the larger hose takes over. What do you guys think of that? I may try to duplicate it.
First off i capped off all my vaccum lines to my manifold that go to my crankcase. I figured out whoever had the car before me hooked up the catch can wrong too. I machined a hole in the top of my catch can for a pop in filet and added another fitting to the can and hooked those cent lines to the passenger side valve cover and the valley cover. Basically just allow the crankcase to breathe in its own. Not the best or most ideal thing to do in my opinion. It will likely work but I think I’m going to do something else. Something I feel would be better. I work at a dealership and I had one of our factory turbo cars in the shop. I looked how the factory did it, they have a 3/8 hose going from the valve cover to engine vaccum, Check valve in the valve cover. Then they have a 3/4” hose hose going from the other side of the valve cover, baffled I’m sure, to the intake filter side of the turbo. My therory is the vacuum takes care of evacuation at idle and low loads and higher loads the larger hose takes over. What do you guys think of that? I may try to duplicate it.
3/8" hose for the vacuum side with a check valve in between the intake and can, -12AN hose from the drivers side valve cover to the can with a small remote mounted filter on the passenger fender well coming off the passenger valve cover.
This way when the engine sees boost the -12 provides plenty of unrestricted flow for the crank case keeping things like your oil dipstick from shooting out and spraying oil everywhere....been there, done that lol.
Now your can has no filter so the 3/4" or -12AN line coming off the engine will need to go somewhere, either to the turbo inlet or have it's own filter, to the turbo inlet is going to push oil laden air into your intake system.
Again with the MM Can keeps the intake tract squeaky clean.
Ejecto dipsticko cuz lol!!
this is why i like the cfm breather. The check valve keeps it closed during normal driving to keep the maf happy etc etc. It pops open and vents during boost. The check valve pops with little effort and i imagine in my setup its opening all the time when i get into boost. I am at 5.3 psi with the maf installed, around 6 psi without the maf though i have seen 7psi.
No room at the front of the 4th gen unfortunately, not sure if its true or not but I've heard of vacuum pumps pulling oil off vital parts of the rotating assembly when used in a street car application too.
I tried one once. The pulley spacing for proper belt routing was sort of a nightmare. The plumbing was inconvenient, and the brackets had alignment issues. At that point I started thinking about how much it would really have to benefit in order to overcome the parasitic drag, rotational inertia, and added mass of hardware in order to be a benefit. I decided vacuum pumps suck.
I found the suction from the blower inlet through a tiny *** 3/8 line was better then just venting to atmosphere via the huge oil cap hole...whatever size that is. If i had a bigger boost setup id do it the same way but i would modify the valve covers to accept a bigger line and run one off each valve cover.
I found the suction from the blower inlet through a tiny *** 3/8 line was better then just venting to atmosphere via the huge oil cap hole...whatever size that is. If i had a bigger boost setup id do it the same way but i would modify the valve covers to accept a bigger line and run one off each valve cover.
That when I moved to a remote mounted filter on the fender well.
Keeps the intake tract squeaky clean.