Why?

I know the technical explanation that oil isnt a good thing in the IC ... but that doesn't really answer the question.

In other words ... If it was such a huge problem, Why didn't BMW add a catch can? Why isn't it an OEM part? Does BMW know something the aint' telling us or clearly, they deemed it not necessary

Is it just another widget for vendors to sell to the masses?

Is there ANY emperical data that show ANYBODY losing HP without using it?

 

Possible reasons...

Requires draining, so the maintenance load is increased.
Costs money, so they have to charge more.
They just don't care.

I've taken my IC off several times, and without it, you can get a puddle of oil on the floor if you sit your IC there, on end.

Every performance book I've read says put one on to keep the IC efficiency up.

Matt

 

I too have a Alta Oil Catch Can in the box I've not put it on my car as I'm not so sure it's worth it ( I know I spent the $ on it) might as well. Not only that I just put a new GRS IC on & thought now's the time. I guess my big concern is my dealer, they'er so **** about any mods, that they want to drop you from the warranty list. I can't wait to see what they'er going to say about all the stuff I've done since my last visit. It's a long list..........

 

When you pass 50k miles, you just won't care anymore....

But "yumhaggis"? I guess you have to have been brought up on it. Can you really get good haggis in the Bay Area?

Matt

 

But, since everyone loves their dynos, has it ever been emperically proven for a MCS ... cause it looks like just another way for a vendor to sell you a widget

 

Aye, indeed you can Not really, you can't even get good haggis at home, it's more for the tourist. They love all the pomp & ceremony of marching in with a Scotch soaked haggis aflame, but you can buy haggis in a can and it's not half bad, which is to say it's not half good either, and I've been known to have leftover haggis & eggs in the morning for breakfast. Not for everyone, but if you like animal innards cooked with oats & very few herbs sewn up in the gut of the donor animal it just might be for you :impatient yes I like haggis...........

 

Well, my guess, and it really only is a guess, is that extra teaspoon of oil you find in your intercooler would have a second or third order efficiency effect. I suspect that if you do a lot of racing you would get a slight edge with a cleaner intercooler. So, it's likely that for 99% of MINI drivers, the net effect of the OCC is not measurable.

But it sure looks cool with all those tubes and that gleaming aluminum!

 

If that is true, then its just another widget for vendors to sell to consumers and add more complicated parts (simple is better) that can break. I just dont get it.

 

Why would you want to subject your IC and intake system to unwanted oil?

 

That isn't what I'm trying to figure out. If BMW or MINI don't care, and they need to warrant the car, there has to be a reason why.

I am sure vendors will sell you anything your willing to buy. However, I'd like to see hard evidence it really matters but I can't find ANY hard evidence.

 

And I think your right, "vendors will sell us what ever we're willing to buy. As for the real world as someone said earlier we would see little if any difference in performance of our cars with or without it, so as for hard evidence as to an advantage. Not really, but it will look neat with the colors & shiny bling under the bonnet

 

Its about the life of a vehicle... for instance the car will usely get a bump in horsepower say around 1 to 2 hp at around 40,000.. when the engine has been worked into a sweet spot.. the CC tries to extend the life and efficiency of the intercooler..

as for bmw not caring well.. its more like they don't care if you lose hp after a certain number of years.. like an old ferrari.. you'll never get the same hp as it is when its new or in that sweet spot.. thats why i put in my oil catch can.. plus.. its not always about hp.. sometimes its just about running efficiencies that probably can't be measured on a dyno..

 

I think the original question is why wouldn't we want to subject the IC to the unwanted oil.

I'm very interested in our technically savvy population's words of knowledge...

mb

 

Slowride11 has a point about 40K miles making the stock IC more efficient but your not going to feel 1 or 2 HP.

I too would like to see hard data because the answers so far tell me its bling (that nobody is going to see). Nothing wrong with Bling but I'd like somebody with technical savvy to admit that ... or not.

 

What kind of evidence are you talking about? The CC eliminates most of the oil fumes coming from the valve cover from going thru the engine. If you don't want to have a big puddle of oil in you IC then install one. If you don't care then don't. No one has ever claimed that the CC will give you a performance boost. It is about maintenance and keeping the parts clean. My CC fills with oil and water vapors and needs to be emptied about every 3 months or so. I don't want that junk going through my IC, engine, and throttle body.

 

If so, why doesn't BMW care or maybe the figure its OK?

 

Who cares if BMW cares.......I care. BMW may not figure that any kind of failure would happen under "normal" driving conditions, so they didn't think it was worth the added cost. But I don't want the residue to coat the insides of my intake system.

 

I definitely concur with that... also remember that the most bmw will warranty is 100,000 miles... they figure they'll probably not have to worry about any of those issues for the entire life of the car... for them its probably easier and cheaper if someone complained about it and give them a new intercooler or something than put in a Catch can.. especially since they don't want you touching anything in the engine really except maybe to top off your windshield fluids... and as for bling factor.. i guess that has to be taken into account but mine is tuck away by the cowl and pretty hard to see if your not looking for it. and the hoses are black.. so not exactly a stand out ... maintanence is definitely the issue.. will any of that gunk harm the car.. probably not for a long time.. so do it or don't its basically a piece that gives piece of mind.

 

Is not the answer really simple?

If the can catches oil that is places where it needn't be, and if being in those places could potentially inhibit performance, it's pretty much justified imho.

2 factors for why I installed mine.

Longevity. Oil is going to be in the SC & IC anyhow, if it can make it to the OCC. But were those parts meant to be oil cooled or lubricated? I think there would be systems in enhance those functions if so, and not rely on oil making it through the cylinders.

IC efficiency. Almost all of the tuners agree a cooler IC enhances supercharger productivity. Oil is not the best thermal conductor, and when coating metal, can act as an insulating blanket.

How to test? Basically measure how much oil is in your OCC. That's how much is 'not' coating your IC and in your SC. Also, if someone had the cash, measure a car's performance with an stock IC that's been run for a while and coated with oil, and then put on a fresh IC that's oil free, or that's been run with an OCC.

Just my 2 cents, more from a tech perspective than mech.

 

I'm thinking this is a easy one . I live in a hot climate. Having an efficient IC is important to me If i can hold my IC up to the sun and not be able to see thru it due to it being oil clogged I know it is not as efficient as it could be. After cleaning the IC I can celarly see thru the unit and if i can see thru it easier then I know the air is getting thru it easier as well. More air = more efficiency. The oil catch can helps keep the IC clean therefor more efficient. This is just one of the many things which you do not need a dyno sheet to tell you if it works or not.
John

 

I'm thinking that at the one year mark (~30K miles), I'll pull my intercooler off and inspect it for oil. If I find any, I'll clean it and probably install a catch can in such a way that I can ****** it off before it goes in for any service. Ne need to give 'em an excuse...

Rawhyde

 

I posted this previously, estimating the loss in IC cooling efficiency due to the oil film that arises without a CC. The oil film probably does not have much of an effect. If anyone cares to do the experiment to measure the influence of the oil film , though, that would be great!

According to McCabe & Smith, a typical heat transfer coefficient for heating or cooling air is in the range of 1 to 50 watts/(m^2 - deg C). According to Holman, the fouling factor for light oil in a heat exchanger is 0.0007 (m^2 - C)/watt. So, assuming the MCS IC has an internal heat transfer coefficient of 20, we can calculate the heat transfer coeff. of the fouled IC (denoted Ud): .0007 = 1/Ud - 1/20. This gives Ud of about 19.7, or 98.5% of the heat transfer ability of the clean IC.

 

Even though the oil film is thin, it does a heck of a job restricting heat flow. If you think that thin films aren't important, think of coating the entire IC surfaces with saran wrap. It's thin, and it will trash the conductivity. The molecules in oils are long and thin. Think overcooked spagetti. The have high serface tensions, so the film will be continuous, and everywhere. It makes a difference.

For most people, they'd never notice it. Getting all the crap out of the crankcase and burned in the combustion chamber is an easy way for the motor to reduce the hydrocarbon emissions. It burns the blow by, and if it picks up some vapor on the way, so be it. (at least if you're a manufacturer and have to pass emissions) If you put a can in there to capture them, then it would have to be cleaned a couple times a year, something the average driver would never do. When it got full, it would slosh gobs of the stuff into the intake, and you;d get a big fart of smoke out the tailpipe, if you didn't get misfires.

This is a mod for an enthusiast. Why pay $700-$900 for a larger IC only to have some of the benefit taken away by an oil film coating the inside of the expensive add on?

Matt

 

Matt, this is best answer I have received on this question.

If someone is worried about having the car for 100K miles on stock IC, well most people dont come anywhere near that number before dumping the car ... not an issue for the vast majority of owners

Since from previous reading it appears a better than stock IC isn't going to do much without a new head, that brings it to your point. If your going to spend $1K on a GRS or whatever, it goes with that new head and is for the enthusiast, but, I still think, with marginal gains

Thank You!

 

While having an aftermarket IC coated with oil will incur efficiency losses, how would those same losses not apply to a stock IC?

I think it's elitest to assume a generic upgrade only applies to specific parts.

Would not an OCC with a stock IC, somewhat compare to an aftermarket IC without an OCC?