Hi so I am looking at the Driven Fab products and wondering what would be better for our cars? A catch can or an AOS and what the benefits of each would be? Thank you. I know the basics. Relieve pressure, collect oil in the air, but what is the true difference between the two and what do you recommend?

 

They're almost the same thing really. I have the driven fab v3 catch can which I love. Their catch can is a VTA, so its not routed back into the engine. In the winter months I'll fill the can in a month. During the summer I'll collect a small amount.

 

so is it better to have the aos so that the oil can return back to the engine or it really doesnt matter?

 

Its not really oil that you're circulating, its crank case gasses as well. This includes moisture (which usually just gets burned off anyway) and other sh*t. In reality both provide some form of benefit. I just like the idea of having a VTA style catch can because it'll collect the liquid matter and vent the gasses, instead of anything getting circulated back into the intake.

In all seriousness, unless you're pumping serious power they aren't going to help you much aside from kicking you up an octane point or two, and keeping the intake tract clean.

 

I can't say if one is better than the other, but I can tell you that Driven Fab catch can that VTA will smell, unless you like that smell.

I took it off the car because of that, it's back in the box, but I haven't had a chance to sell it off.

 

Use an AOS if you're recirculating. It's designed to condense the liquid and return clean gas back into the intake for recirculation. A catch can will do this to a lesser degree but is more effective if it's VTA (which most emissions states frown on). If you don't like the smell, you can run a line under the car or closer to the ground to knock that smell down inside the car.

 

As a side note, recirculating when you have the air on eliminates the smell. I for one love the smell so I don't mind it at all.

 

Ok so does the AOS automatically drain the liquid collected or do you have to manually drain that yourself? Im using the stock BOV so I am recircing. And if the smell is just burnt oil or something like that ill be fine. Im used to weird smells.

 

well i went with the catch can. should be here next week. install should be easy. i might do a review.

 

LOL, people likes the smell Hmmm. OK, but I am not sure if it is good for your health!

You do need to empty it once in awhile for the Catch Can. If you route the hose down somewhere to the ground for automatic drain, then keep in mind that is illegal.

 

didnt plan on illegally dumping. i might get rid of the filter and make some kind of adapter to vent the gases down.

 

How about running a line and tossing it out the fender vent?

 

that would be illegal but i guess an option? unless youre talking about where the breather filter goes? in which case i was gonna run a line from there but you have to make an adapter first.

 

The filter hole is pretty large so running a tube might be difficult. On the other hand, emptying it is easy as can be. Drive Fab gives you a siphon pump. So all you have to do is take the filter off and pump the contents into a empty water bottle.


This was a pic from last year during the winter. So a lot of it is moisture. One sniff will clear your sinuses lol

 

What came out, is disgusting. But it's good you have the catch can. I think it's important to have even on a stock/mild Evo. I took my car apart this winter, 140k miles with very mild mods (intake/exhaust/OTS tune) with the stock PCV system, and what came out was nasty. Overall healthy strong running engine, but the intake past the PCV vent was just oily muck. Same goes for the intake manifold, throttle body, intercooler pipes, etc.


So I will definitely be doing something about it as I'm putting it back together with the bigger setup and shooting for more power this year.