The merits of breather filters over the line to the intake can be argued but there are people who want a breather filter so I decided to show an easy way to make your own. All you need is the stainless steel breather filter that they sell at your local auto-parts store(I paid $10 IIRC I just had it laying around) and the hose that originally ran from the breather to the intake itself(the 3/8" hose). First, you need to do is rip off the rubber connector that comes on the breather filter. Next, grind down the hole a little to make it easier to fit the hose in there(this isnt necessary, it just makes it easier to get the hose in there because it needs to be a tight fit so it doesnt fall off). Then, cut down the stock hose to your desired lenght and shape. Slip it on and now you have a half-way decent looking breather filter. I aimed mine down a little bit so as not to have splash back on parts of the engine that get hot and would thus cause ugly burning. This is certainly cheaper than buying an expensive one online. Hope this helps some.

 

Now install an oil catch can and really get something out of that.

 

IMO, I'm not really into it... But also, wouldn't you want it angled up and not down? Bumps and hops on road make oil slide everywhere and if it runs into that tube it's going straight down to that filter. Also maybe cooler because it's not sitting on motor. But they do say heat rises.... To each his own I guess

 

But chances of that happening = slim to none lol

 

Put a breather on both valve covers or none at all. Your engine will run lean with one VC still connected to the PCV stsyem and the other one open.

 

I co-sign this post.

 

The other one is already done. I didn't want to bother with the catch can and I couldnt figure out where I would mount it either. Maybe when the SC is on and running it would be worthwhile but for now its easier to throw a filter on the end.

 

I tried putting them on both when I installed my CAI and the engine just ran lean and misfired a bunch. Took em off and ran the lines to the intake piping at all was well.

 

The Berk intake on my car is hooked up that way, to the intake mid pipe. Runs and drives fine without any drama.

 

I dont think it has been proven that you run noticeably leaner with only one breather filter. For a while when I first put on my custom intake I didn't want to cut a hole for the front valve cover breather so I only put the filter on the front. I noticed no change whatsoever. I didn't want to mess with the pcv system at the time as it is fairly important. Some people have problems running only one breather and other dont. I think the people who have problems with the 1 filter set-up have other underlying issues that cause the problems. In reality, the 1 breather filter is doing the exact same thing as the stock setup except for venting the hydrocarbons to the atmosphere and the absence of the vacuum.

 

It for sure made my engine idle stupid and misfire.

 

Most people say that the lean condition of running a breather filter is caused by unmetered air entering the engine that the MAF cant account for and thus the correct amount of fuel isn't delivered. I personally don't think the 1 breather filter set-up would cause any noticeable difference in air/fuel and thats why I recently went back to the stock pcv system after running the 2 filters for 6mnths or so. If I saw a read out and it was substantial then I would of course change my mind. I have not. Every forum seems to have a different opinion on breathers. I ran mine because I didn't want to cut yet another hole in my pretty aluminum pipe and the breather filter was the easy option in that case. Obviously there could be something I don't know, I don't claim to know everything, but the point of the breather filter isn't to allow air in, its to keep the oil out of the intake and cut down on gunk. I tell myself its not rice because of this lol

 

Did you remove the PCV valve as well?
I among others have actually run lean with only one breather. And good luck telling Sparks that he has underlying issues with his car...Go read through his intake threads. You'll learn a lot.
Edit: Here are the main two I was thinking of. http://forums.maxima.org/5th-generat...l?ref=esp-link
http://forums.maxima.org/5th-generat...-ratio-vq.html

Because you don't have a wideband!!

 

He is a wideband.

 

The thing is, the only downside from running 1 breather and not messing with the rear is a minor jump in idle. If I added a breather on the rear and took out the pcv valve and plugged up where it connects to the UIM that would be ideal but the downside of running one isnt great to say the least. You could even just add add on a breather filter directly on top of the PCV valve and plug up where it connects to the UIM.

 

 

what are the idea of installing these?

 

lots of reasons. most do it on boosted applications for necessity but N/A can get benefits from it as well

 

Well would you kindly mention one?

 

You guys do realize that the engine will provide more power with a vacuum applied to the crank case and adding these breathers totally negates that effect...

Ask any true race engine builder about that fact, that's why they run vacuum pumps.

But, hey I guess the breather looks cool.

 

some engines have shown a gain adding breathers. the vacuum pump serves to give more of a vaccuum than stock. taking away the stock vacuum has an almost unnoticeable difference

 

Taken from the second link I posted. http://forums.maxima.org/7924243-post22.html

 

personally unless youre boosted all this thing does is pretty up youre engine bay, and if youre going to add a breather to your car,why not just buy one that is precurved,which they do sell,and remove the ugly black hose all together?? its a direct bolt on and requires no cutting or anything of that nature, i actually has a crack on my midpipe where the hose at one point and it cause the car to randomly shut down while driving,once i rewelded it the problem went away,the random shutdowns were because it served as a vacumm leak on the intake therefore causing something that is normally meant to have vacuum not have any....ust saying its a good writeup and all that,however alot of people are going to flame it due to certain issues they have had in the past..

 

^^^^ this is true.