The purpose of this post is not to discuss the merits of a catch can - that's been beaten to death. Rather, I'm curious about the functions of different catch cans. For simplicity, I'll reference Elite Engineering's catch cans. Elite offers three different catch cans: good, better, and best. My car, by the way, is a '15 Z51. Okay, the "good" catch can has a single inlet and outlet that connects to the "dirty" line of the PCV system. I think it's obvious that this would do a very effective in "catching" the oil. The "better" is the same as the "good," but also has a line for the dry sump oil container. If I understand the "burping" issue correctly, GM lowered the oil capacity .5 quart to correct the problem. If so, what's the purpose of the "clean side" separator? The "best" has the addition of a second outlet line that attaches to the air bridge before the throttle body. It seems to me that this set up could "gunk up" the throttle body and cause issues.

Of the three options, i'd speculate that the "good" catch can would catch 90% of the oil and the other levels just add unnecessary hardware. Again, I am using Elite's catch cans as an example and I've researched other manufactures who also offer different levels of catch cans. As far as I can tell, all the catch can manufactures make a very well engineered quality product.

 

For what its worth this is from elite engineering's web site ....Elite Engineering's PCV Oil Catch Can has a unique 3-chamber design to effectively separate oil from the crankcase vapors, thereby eliminating all negative effects of excessive intake system oil contamination. This was when I looked up good , better, and best they all say ..all negative effects of excessive intake system contamination so maybe it depends on how hard you drive.

 

See this post: https://www.corvetteforum.com/forums...post1589638169

 

Elite Engineering recommended going with the "better" catch can for my Z51.

 

 

I'll provide a 3rd option! I bought essentially the "Best" Elite system but only installed one line on the "catch can" and a 1/4 inch plug on the other since I don't track the car and my high rpm blasts don't last long! That is the defined purpose of the 2nd line going before the throttle body. That line requires drilling a hole in the air intake line and the addition of a check valve in that can exit fitting (or air will just flow from one line to the other!) (Note I do not have a check valve in my single outlet since IMO it is not needed and could cause more flow restriction than the OEM line removed.) The reason given for the 2nd line is the reversion pulses occurring on the intake at WOT. The average pressure must be lower in the intake manifold that before the throttle body (to flow air in that direction) but apparently these reversion spikes cause less pull from the crankcase.
I have the extra line, elbow fitting with check valve "if" I every decide to add it. However I can also convert back to stock in a mater of minutes!
The issue with oil in the air intake coming from the dry sump tank is different. GM has listed the same amount of oil in the Z51 from when I got my car in October 2013! They had an errata sheet in the Owner's Manual as to the volume of oil require. They did not say anything about the dip stick level! However some of us elect to keep the oil 1/2 quart low, which is 1/2 way in the hatched area on the dip stick. That is NOT a GM suggestion. In fact it appears to me from reading many forum posts the problem is some dealers using the GM published oil volume or more and over filling! I just fill about a quart low and top off to 1/2 way in the hatched area.
Having said that I still have a catch can, cheap insurance IMO. To pump all the oil out of the pan a lot of air gets pumped as well. That air must be "burped" from the dry sump tank and only oil returned to the engine. That "burped air" goes into the air intake just after the air cleaner. It will contain some oil vapor or mist. The Clean Air Oil Separator contains the same stainless ribbon material as the Catch Can. It condenses some of the oil mist so it drops back into the dry sump tank. How much does it catch? How much goes to the intake if you don't have it? Who knows but it will "cause no harm" so why not!
Bottom Line: Their "Better" system may be the preferred choice as I see now they add two exit fittings with check valves with the "Best" system. A check valve is not needed if not installing the 2nd line and I view it as an extra restriction in the PVC line, which the OEM line does not have. Or if doing as I did ask them for one fitting without the check valve and to install a plug in the other.

 

Zymurgy............Thanks for the link, but I don't see how it addresses my questions.

JerryU.........."Who knows but it will "cause no harm" so why not!" I agree, but why spend an additional $100 (better) or $175 (best) on something that has little or no benefit? From your post, you bought the "best," but, by having the second exit line pluged, you are, essentially, using the "better" can. Why pay extra for the "best" can?

To repeat, I am not bashing Elite Engineering. In fact, I think they make an excellent product and have the experience to know what they are doing.

 

I posted that link because JPD Motorsports recommended the standard can for most:

My personal recommendation...

If you have a non-Z51, the "Good" is all you need. If you have a Z51, then go with the "Better" to get the clean side separator. If you are boosted, go for the "Best".

 

Zymurgy............I agree with your "personal recommendation." It's good to see Elite Engineering has covered all the bases.

 

At such a small price difference, I just went with the "best" option.



I like how people always say stuff like "if I ever want to go back to stock..."
Like they are going worry about pulling their catch-can before they sell their car?

I don't get it - especially if it is vehicle specific.

 

Most folks may elect to just get the Better system.


JerryU.........."Who knows but it will "cause no harm" so why not!" I agree, but why spend an additional $100 (better) or $175 (best) on something that has little or no benefit? From your post, you bought the "best," but, by having the second exit line pluged, you are, essentially, using the "better" can. Why pay extra for the "best" can?

Like my "who knows," where I can't quantify now much a "clean air separator" helps since I have no way to quantify how bad it is without one! (However lots of reports of oil in the air duct and I don't have any. I also snap my fingers and have no elephants in my refrigerator. Bad old joke!) Feel the same with spending the extra money I did with the ability to add the extra line if and when I think it would be a benefit (still don't.) Cheap if I want to add later versus buying a new two exit can.


If I trade the car in I may remove it, could be considered an issue with some dealers. If I sell on my own, depending what the verdict is in 3 more years on its benefits, may also decide to remove it. (Will get a new Vette when this one is 5 years old, maybe it will fit!)
Currently I see no need, from the way I use the car, to add the 2nd line.

 

What's the best catch can for my non z51 soon to be modded and supercharged

 

If you don't have a dry sump engine (Z51 & Z06) you don't need the clean side separator. So I'd go with the "Better" and install both exits.

 

I agree that the clean side separator is not needed in this case, but the "Better" comes with the clean side separator. Additionally, the "Better" does not come with the E2 (two exit ports) catch can. So, "Better" is not what to get.

What Seannyc needs is to just get the E2 catch can without the clean side separator: http://www.eliteengineeringusa.com/e...-catch-can-e2/.

 

i don't see any check valves here, so how are they keeping the vacuum from sucking fresh air in front of the throttle body vs. from the valley plate like it is supposed to?


what do they do for forced induction, this would further complicate things.

 

Elite offers integrated check valves. The exit ports can have check valves in them. You can't tell from looking at the outside.

 

RX Performance catch can. Google it, get to their web site and click on the link that mentions something about "Take the Challenge". or something like that.

 

Sorry, got confused about good / better / best. Yes, what Zymurgy said.

 

Thanks guys

 

Do I get e2 dual exit ports with double exit check valve or e2 single exit ports with single exit check valve