[Rayknee]

Hey all,

I got my Camaro about a month ago and absolutely love it. I've got roughly 1,400 miles on it and am looking forward to driving it again come spring.

Anyhow, I've been reading up on the whole "catch can" debate and I'm trying to figure out if it makes sense. My friend has a BMW 335i thats tuned and has had a catch can since I believe 2500 miles. It now has 65,000 on it and he just recently did the Walnut blast due to carbon buildup. Now, I understand it's tuned but the catch can obviously didn't really prevent the problem. It maybe prolonged it, but it certainly didn't stop it.

Then on the other side of the spectrum another buddy of mine has a '15 Denali 6.2 that he drives hard and uses like a truck. No catch can, but has a Borla exhaust that was on it at dealer delivery. It currently has 28,000 some odd miles.

Now here is the rub, my buddy with the Denali took it to a test and tune one night when he had 3300 miles on it and then this past month.

The truck got faster between both visits. Consistent over multiple passes. Ambient conditions were similar and it was the same track. This being a truck that has NOT had an easy life. The oil is changed based on the computer...it lives in a dusty, wintry environment and is used year round like a truck. It's probably also had 87 octane crap gas in it at various points. Yet, the degradation in power that is often spoken of hasn't been really noticed. I guess you could argue that it would be faster still if it was port injected and not have any build-up at all...but my point stands. The truck isn't getting slower or losing gas mileage.

So I see these two scenarios...and I wonder if the catch-can really truly is necessary. I know my two stories are anecdotal but it's still real world experience. So I'm leaning toward NOT using a catch can and wanted to hear if others are doing the same.

Let me be clear, I'm not bashing catch-cans or the vendors that make them. I'm sure it's a quality product and I know people believe in them. I respect the vendors here that have given their time and efforts to educate on the benefits of their system. I'm just leaning towards running top-tier fuel and early synthetic changes and driving the car hard vs going catch-can. To me that might be enough to mitigate the concern for the five or so years I plan to own this car. So I want hear from the people that are driving these cars that have not gone down the catch-can path. How is your car running, what's the mileage...do you have any concerns??

[Glen e]

I don't run a Catch can on my Camaro or my Corvette. My C7 Corvette had the LT1 engine, because my car is in around town driver, and also after working for three car manufactures all my life, I can tell you that they test these engines way, way out from what most people will ever use them for, so that they don't have to eat up the cost of their profit in warranty costs… So there's a vested interest to make them right at the start. Also here is a great article that was posted On the Corvette forum by Mike Furman, a Corvette forum dealer, (like Becky) when he asked his GM contacts about Catch cans.

I don't think they're a scam, I have friends that have them and they work, I just don't think that they're absolutely necessary for everyone.

Written to mike at Criswell when he asked one of his engineering buddies about this…

I was the one that contacted someone from the Stingray Consultant team from GM...Here comes is what he wrote back on this matter.

"The Stingray was evaluated with over one million development miles on 200 captured test fleet cars. There are tens of thousands of direct injection vehicles on the road from General Motors alone. During the evaluation hundreds of engines were literally torn down in to part piles and evaluated. There are hundreds of thousands of LSx family of motors (where part of this catch can hype started) on the roads and the many of these motors are running well past 250,000 miles without a catch can.

The cars have a 100,000 mile powertrain warranty and that includes mechanical failure of the engine. Trust me when I tell you that there are not reams of data (not even pages of data) on cars coming up lame because of oil at the MAF. It just isn't the problem that the "internet" makes it out to be. When you ask a GM Powertrain engineer about a catch can the reply is that the only thing you get is added weight.

In looking at the extra effort and added cost that went in to the Stingray, do you really believe for one second that if a $20.00 part attached to the engine would improve reliability, limit warranty claims and replacement costs, that GM wouldn't have put it on if it was necessary as part of their evaluation?

Every single GM engineer that I have spoken with told me in one form or another that a catch can is predominately a "gimmick" device created by tuners looking to make a few extra bucks on their engine modifications.

As a by-product of the PCV system, excess oil vapor is recycled to prevent it from leaching out in to the environment. It will condense back in to liquid if the temperature and environmental conditions are right. A catch can is an oil separator device. It allows the heavier oil in liquid to condense in the bottom of the can and only pass the air (gases) back. This is basically the same thing that is happening at the front of the MAF where most of the oil can be found.

The theory is that this oil in the intake system will collect on the valves and in the cylinders and cause excess carbon deposits. The catch can will reduce (not eliminate) oil pooling in the MAF.

Where the plan breaks down is that there aren't thousands of cars detonating because of the oil. As I told you on the phone, This isn't new. The engines are designed to deal with a quantity of oil mist presented via the intake.

You asked what I should tell the customer, my answer is I'm not sure because I don't know what his question is. If the question is is this normal? The answer is yes. If the question is should I put a catch can on? The answer is what ever makes you feel better. If the question is do I need a catch can? The answer is a resounding no. If the reply is that they saw it on the internet, apologize politely and tell them virtually every thread about it has started with a vendor selling a product or a consumer that was fooled by the hype and trying to make themselves feel better about their purchase by getting others to agree with them.

If he has concerns about his condition he should take the car to his dealer for evaluation.

Here is my standard response to the dozens of emails I get each year with a link to a thread like you posted (and often, that very same thread).

Simply stated, absolutely not on the catch can. It simply isn’t warranted for any street driven car. We can talk in more detail about it tomorrow and Dan will appreciate it as I’ve all ready had this conversation with him as well. Since the advent of the PCV system, cars have released some oil in places where it wouldn’t normally have gone in a fully sealed system. It ends up in vapor which condenses back in to liquid form in the intake path. As a result of that, the system is designed to ingest and subsequently digest some extra oil. Higher revving produces more oil and repeated higher revving (drag racer, track duty car, etc.) would be in the realm of uses that I might consider adding the can. Daily driving, occasional back road romp or stop light to stop light burst, not so much.

With all of that said, they won’t hurt anything. For those that don’t want to take my word for it, can feel comfortable adding it but it won’t make an appreciable difference in the life of the motor or the efficiency of the system.
If you dig deep enough in to forum information about catch cans, all roads generally lead back to a performance tuner, aftermarket part supplier or fabricator who has a vested interest in selling catch cans." Stingray Consultant


Mike Furman ~
"Be kinder than necessary, for everyone you meet is fighting some kind of battle"

[moonrider]

I have 5000 miles on my 2SS and have no plans for a catch can.

[DiGiam]

I put one on my car when i went to a ported intake manifold. The stock manifold had oil in it everywhere. It was not just a little bit. I don't want that oil in the combustion process causing a lower resistance to detonation. My car is normal as well. car ran 12.2@116 bone stock so its not excessive blow by either. Im sure the car will last a long time without a catch can and never really be a problem but to keep the timing and power where it needs to be, ill run one

[Megahurtz]

Dont waste your money. It's a worthless mod on a LT1. I've had cars making upwards of 750HP and never ran a catch can on those either. There is going to be a small amount of oil vapor in any engine. It's normal. Race cars run them for a reason. You're not driving around at 6500 RPMs 99% of the time. Don't buy into the Internet hype.

[KMPrenger]

I'm not for or against it really (although I do have a used Mishimoto can I got used for a good price that I have YET to install).

But GM did put a catch can on the LT1 in the Camaro. So obviously they feel its important. They invested much time effort and money into it. The cans we see everyone adding on the SS is simply a secondary can for the "clean" side intake.

So the argument that it isn't needed is also pretty difficult to swallow when you consider that.

[Burly]

A racing friend of mine told me it's not worth it. He's used them before and saw very little difference. I am on fence about it, I get why you want it, but is it worth it?

[Glen e]

Originally Posted by Burly

A racing friend of mine told me it's not worth it. He's used them before and saw very little difference. I am on fence about it, I get why you want it, but is it worth it?

If you are the type of person that really dotes on your car, is going to keep it 300,000 miles, and changes your oil at 3000, then get the Can. However , if it's just a nice car to you, and you're going to trade it in a couple 3-4 years, you don't have to, the car will be fine.

[DiGiam]

When you start pushing the envelope of timing on pump gas, you want as LITTLE oil or oil vapor as you can in the combustion process. I have seen first hand how much oil was in my intake manifold. On a stockish car, yes it may be overkill but when you start adding mods and pushing timing to the edge, its nice insurance to make sure your getting as much timing as possible. Is it going to help you make a million more HP, no but you will be able to maintain max timing easier.

[cooden]

No catch can for me. They are not needed--period. Everything I have seen is based on opinions, not facts. If it makes you "feel" better, then install one. People arguing about the benefits of catch cans are usually the same ones saying not to trust the oil life computer in the car..........

[Megahurtz]

GM put the additional oil vapor control in place (or OEM catch cans if you so call it) to help reduce carbon build up on the valves that is common on Direct Injection motors. This was a move to reduce maintenance needs/costs. Strangely enough the LT1 in the Corvette's do not have this. So I don't believe there is any need to go above and beyond what the GM engineers did in regards to adding an aftermarket catch can. At least not until you get into the extremely modified arena. Turbo and Supercharged cars would more likely benefit from aftermarket catch cans at high boost levels.

[tcbracing]

No can here and no plans. I work at GM and agree with the post that Glen copied - there are literally MILLIONS of test miles without it and if it added that much reliability, it would be there.

[KMPrenger]

Originally Posted by tcbracing

No can here and no plans. I work at GM and agree with the post that Glen copied - there are literally MILLIONS of test miles without it and if it added that much reliability, it would be there.

But it is there....the LT1 in the Camaro has a catch can. The ones being added are just secondary.

[Burly]

Originally Posted by Glen e

If you are the type of person that really dotes on your car, is going to keep it 300,000 miles, and changes your oil at 3000, then get the Can. However , if it's just a nice car to you, and you're going to trade it in a couple 3-4 years, you don't have to, the car will be fine.

I am keeping her long term and definitely guilty of doting. It can't hurt to have one and don't want her to get slower.