Catch Can Debate

[yomny]

Yeah. I'll need to educate myself on the subject because that whole thing above made me dizzy. Not trying to be sunical but i don't understand the next thing about the subject. I've just read that is good to remove the oil from the crankcase ventilation as to avoid clogging the intake and valves and what not. Now that boost is being added the gases and oil will increase with more reason to add a catch can. So again if I had to choose I'll just add a can to the pcv to manifold that's boost compatible?

[Calum]

Originally Posted by yomny

Yeah. I'll need to educate myself on the subject because that whole thing above made me dizzy. Not trying to be sunical but i don't understand the next thing about the subject. I've just read that is good to remove the oil from the crankcase ventilation as to avoid clogging the intake and valves and what not. Now that boost is being added the gases and oil will increase with more reason to add a catch can. So again if I had to choose I'll just add a can to the pcv to manifold that's boost compatible?

Yes, add a can. The debate is sealed versus vented, not can versus stock. The stock system is one small step above horrible as it sits, on that I'm pretty sure all parties will agree.

[Rosticles]

I'm a bit confused by your post. Is it a debate, a question, or an argument? I agree with absolutely every fact that you stated in your post. I just don't know if you are wanting a response, and if so what kind.

Originally Posted by Calum

I've had this debate too many times on here so I try to avoid it now. But I'm bored so I'll jump in.

Why use a setup to redirect?

To try and get the best of both worlds. I agree there can be flow restrictions that I will try to minimize with quality valves that engage as close to atm as possible.

I have zero desire to reopen the old arguments.

Can vs. No can? Breather vs. Closed? Single vs Dual can?

I've tried to be as unbiased as possible here but if my bias does show through it's only this one mans opinion.

It sounds like you think an open breather is the best. Is that the case? Do you think my arrangement is overly complicated or bad for a reason other than the, aforementioned, flow issue?

[Calum]

Originally Posted by Rosticles

I'm a bit confused by your post. Is it a debate, a question, or an argument? I agree with absolutely every fact that you stated in your post. I just don't know if you are wanting a response, and if so what kind.

It's a question that turned into a debate and then quickly rolled into an argument.

Originally Posted by Rosticles

Can vs. No can? Breather vs. Closed? Single vs Dual can?

The old question was always breather vs. closed. Get a can, atleast one. Two is better.

Originally Posted by Rosticles

To try and get the best of both worlds. I agree there can be flow restrictions that I will try to minimize with quality valves that engage as close to atm as possible.

Do you think my arrangement is overly complicated or bad for a reason other than the, aforementioned, flow issue?

I think your proposed arrangement is fine, it wont hurt anything and may be advantageous. But my instinct is that your proposed setup wont gain anything over the dual can setup, it'll just add complication and cost you money. Its not much money or complication, though.

One thing you should remember is that the function of a PCV valve on an NA car isn't to act as a check valve. The chances of the intake manifold pressurizing on a NA car is very slim. The purpose of the PCV valve is to regulate flow under different engine operating conditions. So, if you maintain a system that pulls a vacuum on the crankcase, use a PCV valve. If you go FI, keep the PCV valve but add a check valve to the PCV hose to prevent boost from pressurizing the crankcase.

[yomny]

So whats better for boosted applications? Closed would route the pressure back into the car so a boosted car would benefit from venting or is this one of those questions that don't have an answer? Thanks in advance.

[Calum]

Originally Posted by yomny

So whats better for boosted applications? Closed would route the pressure back into the car so a boosted car would benefit from venting or is this one of those questions that don't have an answer? Thanks in advance.

A closed system on a boosted street application will still pull a vacuum on the crankcase most of the time. The throttle keeps a vacuum in the intake manifold which can then be used to evacuate gasses from the crankcase. Only under heavy throttle, when the intake manifold is pressurized, will the pcv line be closed off by a check valve, thus making the system a vent to atmosphere style system for those brief moments.

Which is better for forced induction is up for debate and depends on the application. How much time will you spend with the intake in a vacuum versus how much time it'll be pressurized.

[wbradley]

Originally Posted by mit_peid

I have a single can only on the PCV side and noticed this morning that it is actually doing something. Worthwhile $100 investment I think. Attachment 98089

I have the same can with stainless steel wool stuffed inside to provide some baffle. I can confirm it collects absolutely nothing in my N/A application.

[Wes]

Originally Posted by wbradley

I have the same can with stainless steel wool stuffed inside to provide some baffle. I can confirm it collects absolutely nothing in my N/A application.

i didnt collect anything in my cusco one, so i just sold it after a year lol
some other ones actually seem to catch blow by though..

[Ultramaroon]

Originally Posted by wbradley

I have the same can with stainless steel wool stuffed inside to provide some baffle. I can confirm it collects absolutely nothing in my N/A application.

Originally Posted by Wes

i didnt collect anything in my cusco one, so i just sold it after a year lol
some other ones actually seem to catch blow by though..

where else would 6 oz oil go in 1 day?

[wbradley]

Originally Posted by Ultramaroon

where else would 6 oz oil go in 1 day?

6 oz in 1 day? WTF!

[Ultramaroon]

Originally Posted by wbradley

6 oz in 1 day? WTF!

Yup. Swore off of tracking until I make absolutely certain I'm not getting starvation. That was my first track day, last August. I did the standard 4, 20-minute heats.

Stock tires. Uses zero oil DD.


My instructor seemed unusually impressed with my performance <wootwoot> but I was under the impression the Michelins weren't sticky enough to really get the oil to hang up.

[Fizz]

Anyone here running the AVO street breather tank....do you know if it has internal baffles or just empty chambers?

This one: http://www.avoturbo.com/avoshop/brea...eet-p-930.html

[Ashikabi]

I'm gonna resurrect this thread instead of making a new one.

I saw a bunch of folks mention running one catch can per pcv valve or a dual can... this makes sense. My question is, why don't you just use one catch can and use a Y splitter to combine your pcv hoses?

[JohnJuan]

Originally Posted by Ashikabi

I'm gonna resurrect this thread instead of making a new one.

I saw a bunch of folks mention running one catch can per pcv valve or a dual can... this makes sense. My question is, why don't you just use one catch can and use a Y splitter to combine your pcv hoses?

One hose has significantly higher pressure, so it ends up blowing into the PCV opening.

Originally Posted by Mishimoto

One Car, Two Cans

We will be designing a kit with two cans, one for each of the systems. Unfortunately, these lines cannot be combined into a single catch can due to pressure differences. We will be selecting optimal engine bay locations to ensure that the cans are not impeding space for other components. Also, for our RHD (right-hand-drive) owners, the firewall differences between the two cans will be important. To ensure we will need two catch cans, we will be testing both systems to see which produces a greater amount of byproduct. More on that below!