Venturi catch can setup

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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I was doing some googling on doing a catch can setup for my L5P and realized these things stock have something like the LB7 catch setup but uses a Venturi effect on pulling out positive pressure.

Anyone know if it’s decent, stock? Would rather either re-route it to atmosphere now or put something on that works well now before the egr and it start making the sticky mess in the intake tract.
 

juddski88

Freedom Diesel
Jul 1, 2008
4,657
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Chesterfield, Mass.
I was doing some googling on doing a catch can setup for my L5P and realized these things stock have something like the LB7 catch setup but uses a Venturi effect on pulling out positive pressure.

Anyone know if it’s decent, stock? Would rather either re-route it to atmosphere now or put something on that works well now before the egr and it start making the sticky mess in the intake tract.

I haven't looked at the l5p PCV system lately, but lly - lml used the Venturi effect also. The purpose of the diaphragms in the valve covers is to regulate crankcase vapors under high-suction. Meaning that when the turbo is creating enough vacuum in the pcv hose, it pulls the diaphragms shut. The flow path is normally held open by the spring under the diaphragm unless under high load. I've found that the diaphragms warp and distort, just like any regulator soft parts do, and fail to seal over time.
 

techperry

GM Diesel Tech
Jun 1, 2014
47
0
6
From the gm training video it should work amazing to keep oil out of the turbo and intercooler. There seems to be alot of thought put into it. I havent seen L5Ps oil the intercooler boots like older models.
 

Ne-max

I like turtles
Nov 15, 2011
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Lincoln, Ne
From the gm training video it should work amazing to keep oil out of the turbo and intercooler. There seems to be alot of thought put into it. I havent seen L5Ps oil the intercooler boots like older models.

They are just as bad. We just replaced a turbo on a 18 with 220k on it. Was nasty.
 

M.A.M.

Member
Jan 9, 2016
429
7
18
Ohio
This is what the inside of the compressor outlet and boot looked like at 150k. FWIW, I didn’t have any residue on the outside of the boot. It seems to be a gummier/thicker residue, probably because of the venturi pulling anything thinner out of it.

b0ff9386b4fd5abe2c5d36827a2c3c26.jpg
074993eea78421225143e5d4b1b124df.jpg

baeb16868b3c1954600a0f886e73688d.jpg



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Chevy1925

don't know sh!t about IFS
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Well that answers that!

Being that I’ve looked 0 under the hood for the catch can setup. Is it worth leaving the can and just dumping the hose to atmosphere or just do it the old school way and delete it all with hoses to atmosphere?
 

Chevy1925

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No idea. Like I said, I’ve not gotten under the hood much looking at parts. Wherli only lists for 17-19 and actually doesn’t show the kit on their site (found it elsewhere on google). They want to sell you a bigger intake horn like the lb7’s did as well and I don’t care for that. Reading their instructions, if it’s all the same, it will be real easy to vent to atmosphere. Hose barb, hose and a plug for the open hole on the horn
 

Chevy1925

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c599839c89b50ac9df2209e762f043f9.jpg


Looks the exact same. Going to do some stuff with the kids this morning, then I’ll see about pulling the intake horn as well and rerouting the pcv. Might be able to do my own bigger horn mod like my lb7 one I did.
 

ikeG

Oughta Know Better
Apr 19, 2011
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There are a few visible differences between the 17-19 & the new style. I only saw under hood of 1 2020 just for 30 seconds or so. Biggest thing I noticed was the oil fill.

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Chevy1925

don't know sh!t about IFS
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Banks covers the major stuff, it’s the little shit like a slightly different bolt pattern, slightly different sizes or change in how things are ran that he won’t see until they try to fit a part. That’s the shit that always bites ya in the butt when you try older model parts on a new model.

I won’t be the test pig unless the part is free or cheap or I know you
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Just down right...... over there..... under that..... by the hose...... next to the wires...... by the pipe
 

Dozerboy

Well-known member
Jun 23, 2009
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Geezus, where's the turbo in that mess?



LOL I’m glad I’m not the only one that was thinking that. I can see where the air goes into the turbo and where it comes out of the turbo. I’ll be damned to hell if I see a turbo in the middle.....


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