Vented VS. Sealed Catch Can Test! Which is best? Watch to find out!

Ever wonder which catch can/breather system is better between a vented style system and a sealed style system? If so what to find out!
Using my 9 second (best ET at the time 9.98@147mph) 2003 EVO 8 running 45 PSI on a Forced Performance Zero Turbo I decided to test a Saikou Michi vent to atmosphere dual catch can system, as well as a Saikou Michi sealed dual catch can system to see which was most efficient on my configuration.
Disclaimer: This is not a one-size-fits-all answer. I realize that with different HP levels, variables, components, configurations the results could be different, but wanted to share my results for my particular configuration at this given time. Use the information as you see fit, and enjoy!
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[@Gusando]

Thank you for your service to the Evo community! we salute you.

[@HochmanFabricationAndSpeed]

Our pleasure!

[@MrJRusty15]

Thanks for posting this video. I've been spending some time recently researching vented vs sealed catch cans myself, for my evo 8. I think I recently landed on dual sealed catch cans and your video confirms my decision. Basically, the system is designed the way it is for a reason...it is efficient. There are two problems people run into when going bigger turbo and more boost. 1) oil getting into the intake and 2) the system not being able to relieve enough crankcase pressure in modified cars. The sealed setup maintains the design of efficiency, but upgrading the size of the hoses allows more pressure to escape. With a vented setup, there is nothing to draw out the vapors from the crank case under boost conditions since the PCV is closed. The vent tube just has atmospheric pressure, so I'm not surprised you saw 0psi under boost.

[@HochmanFabricationAndSpeed]

Glad we could help!

[@johngallagher5708]

9:53 9:53 😅❤❤

[@johngallagher5708]

😅0😅

[@johngallagher5708]

0

[@johngallagher5708]

😅

[@topmodstv3682]

I've been researching this for days trying to find out what how to keep stock PCV as well as pull a crankcase vacuum under boost on my foxbody mustang. I finally figured it out. And now I'm glad I didn't vent to atmosphere. I'll do this same test as soon as it's all set up

[@HochmanFabricationAndSpeed]

Glad we could help!

[@topmodstv3682]

@@CRZ_GT It’s almost identical to the sealed setup shown in this video

[@thiagofeltrin9841]

I expected to see how many oil it got on the closed setup, but still you have helped me a lot! I own a VW 1.0 TSI and your words have been a light on the tunnel ♡ And gosh what a beautiful and clean project car you have! It is like looking at a mesmerizing jewelry!

[@vstrom9586]

Everything is so clean & organized - a great video

[@HochmanFabricationAndSpeed]

Thanks for watching

[@Ik13454]

Srt4 here.this was a great comparison and I appreciate your non bias,and test !!!!!

[@tedhollister5814]

Fantastic video. Im currently running the radium dual catch can closed loop system on my Volvo c30 and have always wondered whether or not I should vent to atmosphere. If there are others out there wondering about catch cans this is an excellent video. Thanks again for the time well spent.

[@HochmanFabricationAndSpeed]

Thank you, feel free to share this video with anyone who you think may benefit from it!

[@AndreyFormigari]

Hi Ted. I have Volvo C30 T5... I use two catch can. first (1 in and 1 out) is capturing the vapor from the head and the second (2 in and 1 out) is capturing the vapor from the PCV. However, I've read a lot about problems they can cause when there's no vacuum in the crankcase, where less sealing in the piston rings and more oil contamination is reported. Did you manage to resolve your question?

[@igorbystrika1361]

Thank you for the test and explanation, my turbo is leaking oil and that's the first thing Fp asked if I'm using this set up(non vented)

[@HochmanFabricationAndSpeed]

Glad we could help!

[@StixGarage]

Really helpful test...makes slot of sense. Thanks for taking the time to do this test. I'm sure it was time consuming.

[@HochmanFabricationAndSpeed]

Thank you!

[@hypnotik174]

this was the perfect video i was looking for

[@OpenLogicEFI]

Fantastic video with a result I didn't expect to be so drastic.

[@dominikkozela9763]

Thank you for this video and showing actual data

[@notaloli]

great vid!

[@Chief1063]

Beautiful car and info. Please record wide-screen next time. 🙏

[@minimanadam]

Absolutely amazing car man...omg

[@HochmanFabricationAndSpeed]

Thank you!

[@iamasmurf1122]

Stop recording vertical !!

[@rhysbertrand8903]

Its 2020, most people watch On their phones.

[@HochmanFabricationAndSpeed]

Sorry will do!

[@cmattdabrat]

Very helpful, even for a non Evo owner. With the sealed system, have you noticed any oil residue inside the intake? That's the only thing keeping me from doing a close system again because eventually the entire cold side was coated with a film. Also, what are your through on a venturi tube vs just a AN fitting welded on?

[@Yo-HoLD-mY-WeeD]

It’s ok to put Teflon tape on the npt bungs that connects to the fitting right.

[@Countryboy81]

I do believe the oil seeping from the turbo does not come from the turbo itself. The CCV pushes some oil into the turo intake making it seep oil. The reason for more oil after a turbo upgrade is because the higher the boost the more CCV

[@HeadBassVTEC]

the moisture is a condensation buildup on the catch can itself, not something that would get into your engine without having a catch can ;o]]

[@ka124as]

Yep. People make a problem where there’s no problem lol. “But look at the liquid”. Exactly. They don’t understand how expanded hot air works.

[@3kkk514]

The catch can with vent can you check if your emission is high compare to non vent catch can. Here all cars 10 yrs older will go for national car testing every year including emission test.

[@HochmanFabricationAndSpeed]

Emissions will always be higher with a vented can.

[@anthonyfauceglia5116]

Thanks for doing this!

[@nv_built]

very good video and beautiful setup.

[@HochmanFabricationAndSpeed]

Thank you very much!

[@THeo4131]

Very informative, Thank you very much ! Keep it up !

[@HochmanFabricationAndSpeed]

Thank you! Will do!

[@champspec]

Pretty sweet Evo you got there! I do see a couple issues with your first setup.. the catch can should never be mounted down much below the intake manifold or valve cover. Take gravity into account. Your engine is a giant vacuum pump and you have a line sucking air and oil from an area on your engine that has oil circulating into it. By putting the can down low, where is all the oil going to go? Next issue is the fact that the -10 fitting is not baffled. The pcv fittings or bungs in ANY engine should have baffling to help separate the air and gasses from the oil. Thirdly, you should have a check valve on that line so if it’s connected directly to the manifold. If it’s connected to the charge side of the turbo, then you don’t need one. I think that’s how you ended the video. There’s also a company that has an adjustable flow billet pcv valve. It’s a pretty slick setup. You can tune the valve depending on your setup. They’re based out of the US and it works on all combustion engines.

[@HochmanFabricationAndSpeed]

Thanks for the feedback!

[@dgpgarage9291]

Did you watch the video? It’s plumbed pre turbo, no need for a check valve… also the can is baffled no need to baffle the line…. Third, he’s sucking from the top of the valve cover, he can mount the catch can where ever he wants oil from the engine isn’t going to magically climb to the top of the engine regardless of gravity. He’s pulling oil vapor as he should

[@efjiongco]

Thankyou!!!!! This video was awesome!

[@Zspeed]

Thanks for sharing!!!

[@HochmanFabricationAndSpeed]

My pleasure!!

[@HochmanFabricationAndSpeed]

Yes it should, the PCV is in place during this video

[@Don.Rock0]

What is we are also running a line from the crank?

[@iron-gamerstv]

Great video..one question? How bad is the oil or gas smell from both systems?

[@skippysvr4586]

I mount my catch can higher than the head so gravity doesn't help fill the can. And any oil goes back to head.

[@jimmyounsamone2912]

Should i do a dual catch can closed loop install on a naturally aspirated Nissan 350z?

[@jimmyounsamone2912]

For the second closed loop system did you keep the other sealed catch can on the pcv valve side?

[@SIRICKO]

All catch cans are sealed breather cans only have filters on them.

[@HochmanFabricationAndSpeed]

uh huh.....

[@deathscreton]

Vented VS. Sealed Catch Can Test! Which is best? Probably anything that doesn't cause a vacuum leak on a modern engine. Now Catch Cans vs AOS is a solid question...

[@HochmanFabricationAndSpeed]

Thanks for the input

[@brussell639]

The one worry I can see is it's possible for oil to be reintroduced thru your intake, if the catch can is not 100% effective at filtering the oil out of the air.

[@HochmanFabricationAndSpeed]

Good point

[@oby-1607]

This is KZbin, not Instagram. You can turn your phone sideways for a better video.

[@derargentinier8879]

Great video 👏🏻 resolvió una duda que tenía 👏🏻 Gracias

[@matteo0196]

Very informative video, thank you. When running the sealed setup, is there any concern for the the intake pulling hot air back into the engine? I recently installed the Radium CC on the crankcase side and rerouted it to my intake but it felt like the intake was much hotter than before. I can see why people would vent it instead so now I'm trying to decide on what to do

[@maximumeffort8829]

This was such a great informative video!!! The only question i have is does having a vented catch can affect your boost pressure and the power you make in any way?

[@leasegrandcayman8747]

Interesting results... What if the catch can was vented, but with an added check valve, which would only open if the can was pressurized, in order to vent the pressure out of the system and when vacuum takes over again, the check valve would close and the vacuum would flow again? Wouldn't that be a closed loop with the benefit of venting the pressure to the atmosphere? I have a 3000GT VR4 with larger than stock turbos and I am seeing smoke on deceleration, after going into boost. Only after going into boost... On a couple of occasions, I have seen the dip stick popped out a bit, so I know the crank case gets pressurized at boost. I also know that a bad turbo seal could be causing smoke on deceleration, but the turbos were recently rebuilt, so I am not leaning toward that possibility. What do you think?

[@HochmanFabricationAndSpeed]

Glad I could help!

[@anthonymaldonado8018]

I am seeing the same thing in my Evo X. I have a EFR7163 which utilize double seals on both compressor and exhaust side of the turbo. On deceleration when coming to a stop i get a bluish haze come out of my exhaust and the same thing even if i am sitting still, then rev the engine a little. As the rpms drop to idle, the bluish haze comes out of the car. Happens more on warmer days and less often on colder days as well. I have a sealed system and considering VTA and see what happens.

[@xt5life549]

Forged internals im guessing. Get a lot of blowby? Have to add oil constantly?

[@panasonicchrome7915]

Good Video and Nice Evo :-)

[@HochmanFabricationAndSpeed]

Thanks! 👍

[@sharifmowad627]

This was an awesome test, just wondering how this would play out on engines that are notorious for overheating. Any chance if you recall whether the vented setup was a one-way w/ a check ball valve? I’m guessing it didn’t since you lost negative vacuum during acceleration.

[@villantiofficial]

I have a one way valve that connects my crack case hose into my into tube prior to turbo air in side. Would i use close can system there and incorporate vented can on valve cover with no Out on that? Thank you!

[@isackhernandez3691]

Where can we dump this fuel oil mixture

[@HochmanFabricationAndSpeed]

Bring it to your local auto parts store or oil change station. They will recycle it for you.

[@markm0000]

@@HochmanFabricationAndSpeed You can also just dump it in your lawn mower. It should run fine.

[@farmer3242]

Tip it on your lawn

[@markm0000]

@@farmer3242 Tip it in your windshield washer fluid for extra bug cleaning.

[@farmer3242]

@@markm0000 tip it under your tires and do a burnout on it.

[@ThrowyaXup]

How often do you have to change/clean the breather filter on the open catch can?

[@wurstcrewchief2798]

do you have a list of all the parts you used? AND do you still run this setup?

[@bccapone837]

Ive got the same vent to atmosphere off the head but mine chucks a lot of gunk out and fills up in a few days. The catch can is lower than the head and has small factory tube on it. Do you think it would be ok if I raise the can with a wider tube could that solve the amount I'm throwing out

[@HochmanFabricationAndSpeed]

You can try it, but the cause is likely engine related.

[@bccapone837]

@@HochmanFabricationAndSpeed ah ok cool thanks for the feedback

[@HochmanFabricationAndSpeed]

Anytime!

[@samsonyunited]

So if you do mainly city driving nd short distances you can expect more blowby to accumulate?

[@markm0000]

Ow yeah it’s going to fill up fast. That oil would have been coating the entire intake, turbo, and valves.

[@samsonyunited]

@@markm0000 turned out my engine from esslinger engineering in California installed all pistons backwards. valves didn't clear the cutouts.... dead engine now

[@markm0000]

@@samsonyunited rip 🪦 hopefully they warrantied that mistake.

[@samsonyunited]

@@markm0000 No, and would not recomend them ever again. Even had different cams installed than what I asked to have installed. They must have built it while drunk

[@markm0000]

@@samsonyunited Oh boy. Lesson learned go to a performance shop near your house so you can take them to small claims if they don’t own up to their mistakes. Now I know not to make that mistake.

[@michaelvanna8982]

1.0 vacuum/boost at full throttle? vs 40-45 psi spec?

[@metatronmen2431]

I dont meant to be rude but the video is more about show your car, the result and test can be condensed to few minutes.

[@HochmanFabricationAndSpeed]

Thanks, this is an old video and one of the first I did, I assure you the production value and efficiency has far improved since!

[@bengleckl1877]

So what is the best overall system you came up with??? I have a 22 frontier. I'm not trying to be high performance I just want to prevent carbon build up ....would there be any negatives if I hooked up just one catch can and cented to atmosphere??? No return to the intake ??? Is the return pressure needes for any operation of the engine? Saying creating vaccum or anything??? Im afraid i will mess the engine up

[@Eurolanta6]

Do not vent any modern pcv system. They out side will not pull air from the vent it needs to be pressurized!!! Do not run bigger lines then factory because you will get a lot of gunk and oil thrown to the engine to the out line… If you are using a vented system from pcv to manifold I guarantee you that you’re not even venting your crankcase how as much as it was with the oem setup. Do not vent your system..

[@MasterShake1242]

Are the -10's on free VC drilled to that size or stepped up from stock?

[@BenHochman]

Master Shake they are drilled and tapped for that size

[@MasterShake1242]

@@BenHochman thanks bud

[@HochmanFabricationAndSpeed]

Anytime

[@Airman..]

Genuis

[@bobwhitaker1524]

Awesome video. What do you think the results would be if you combined the two? Running a VTA catch can with a vacuum source? Would it be possible? Counter productive? I ask because I purchased a valve cover with -8an fittings, and I found a vented catch can with the -8an mating fittings so I went that route for simplicity but now I am wondering if it was a mistake.. I make 500hp, 30psi. Eagle Talon

[@BenHochman]

Hey Bob, a common question but a good question, which we get often regarding this topic. On the car in this video its important to understand there are 2 separate catch cans hooked up to the car. One is closed loop (no VTA) that is on the passenger side fire wall and runs from the PCV off the valve cover - to the can -to the intake manifold. This first can remains constant (closed loop) for all tests because it is only used to pull fumes and oil out of the system during idle conditions when the PCV is open. The other (2nd) can is located on the driver side (the one that we use test VTA versus closed loop.) During the first test this was run from the valve cover - to the can which had a filter on it and was VTA (this is the only configuration where you would effectively run both a closed and VTA setup, because you have separate cans on separate systems of the engine.) For the second test this driver side can was converted to a closed loop so it runs from the valve cover - to the can - to the intake with no VTA. So with this in mind to answer your question, if you are running the configruation I described in the first test then yes you are able to run both with a vac source and VTA on the car, however the moment you open the system to a VTA (regardless of having a vacuum connected to it) it is essentially going to perform like a VTA system (just like pulling a hole in a straw and it loses suction power.) As far as which configuration is best for your car, that can be determined only by doing tests similar to this. Each car and its setup/variables require different configurations to accommodate their needs. I ran my driver side can closed loop until this year and once I hit over 700HP my car needed more breathing efficiency up top so I converted all connections from the valve cover to VTA and removed the PCV, at the sacrifice of a little low end efficiency.

[@bobwhitaker1524]

Awesome. Thanks a bunch for the super quick response. I don't have an AEM gauge like yours but I am going to do something similar this weekend with a standard boost gauge. I will start VTA, then seal out the little filters on it and add a vac nipple to the intake and compare. I appreciate it!

[@HochmanFabricationAndSpeed]

Glad to help!

[@RellyOhBoy]

Vertically recorded cell phone vids should be illegal.

[@zerozero1944]

Skip to 13:00

[@MrSnookerballs]

I thought vented was illegal as still allowing fumes in to the atmophere. sealed is legal as no fumes released.

[@HochmanFabricationAndSpeed]

This is true. For a race car or off road use car though some people do choose to go with a vented can.