air breather filters

[IceMan526]

I understand this whole topic and why you would install a catch can. However, do you have to run a line back to the intake? Or can you just run a line to the catch can and vent it with a breather on top?

 

[Calan]

I understand this whole topic and why you would install a catch can. However, do you have to run a line back to the intake? Or can you just run a line to the catch can and vent it with a breather on top?

If you understood the "whole topic", you wouldn't be asking that question.

Here is the article that will answer that question... again: http://www.dsmtuners.com/forums/articles-engine-fuel/366890-4g63t-pcv-system.html

 

[IceMan526]

Ok, bad choice of words . I read through that article and I think I have read it before. But what I still didnt understand from reading it if its actually harmful to just vent it to the atmosphere. In the article they said that you should not do it but they didnt say why or what could happen.

 

[ed1380]

Its not harmful. If you just use a breather filter, then excess crankcase pressure will release through that. But if you route it pre Turbo, there will be a slight vacuum reducing crankcase pressure even more

 

[sax_man]

Best thing I found was to stick a small fuel filter in that line. Keeps you inkate nice and clean and you get the added benefit of having the extra vacuum.

Install a catch can for your DSM (2G)

 

[Calan]

But what I still didnt understand from reading it if its actually harmful to just vent it to the atmosphere. In the article they said that you should not do it but they didnt say why or what could happen.

I said many times in the article why it may be a bad idea.

Its not harmful.

Maybe it is, maybe it isn't. Every car is different, and the only way to know for sure is to measure the crankcase pressure.

If you just use a breather filter, then excess crankcase pressure will release through that.

Yep...once the crankcase pressure is high enough to overcome the pressure drop across the lines and breather. Meaning you'll always have some amount of positive CC pressure. The higher the pressure drop, the more CC pressure you'll have.

Best thing I found was to stick a small fuel filter in that line. Keeps you inkate nice and clean and you get the added benefit of having the extra vacuum.

That's the best thing you've found? Every fuel filter I've seen and tested will either collapse or clog and end up causing a restriction to flow, which actually raises crankcase pressure.

 

[sax_man]

I should have phrased that better. "Most cost effective solution for me."

These things are extremely cheap, and I clean mine about once every two months by dumping out the miniscule amounts of oil that accumulate and flushing it with brake cleaner to clear out any gunk that may be on the filter. I also replace it about every year.

I don't have a lot of blowby or CC pressure, so it's a solution that works well for me and my car.

It also doesn't require shelling out big bucks for a real catch can or dealing with routing and mounting said can.

 

[Calan]

I don't have a lot of blowby or CC pressure, so it's a solution that works well for me.

That's the big ticket item. You have to be careful recommending things like this to others, because every car is so different when it comes to this. Not only that, but the amount of CC pressure will change on a car as the tune or mods change. You may be ditching that fuel filter idea yourself somewhere down the road for some reason.

Out of curiosity, how much CC pressure do you see? Have you actually measured it?