is replacing the tube and putting breathers in its place any good? will it affect anything? what about putting a breather on the intake will that suck more air in?

 

I think so. I would also cut off PCV system as well as EGR system. Those are parasites on the performance and dont affect emission that much. For PCV system simply cork in the intake ports and put the breather (with small filter) on the head port where it goes to the PCV, remove all PCV crap and hoses. Let your back pressure gases escape as soon as they build up, not as soon as PCV valve lets them escape. Also cork in intake ports for EGR system and exhaust port, remove EGR valve and all associated crap. Let more oxigen saturated air flow through the intake instead of exhaust gases diverted by EGR system and PCV system.

 

im currently polluting. the air breathers i found locally were too small, the opening needs to be the size of my thumb or so.. i didnt feel like buyin a converter..

 

There was a post concerning the EGR system from about 6 months ago. i saved the important part. i'm not sure who wrote this, but i think it was phoung - correct me if i'm wrong. here's what he said:

"you'll need to richen the mixture from 1000 rpm to about 3000 rpm, which is the rpm range that the EGR is functional.

everyone thinks that recirculating burnt exhaust gas back into the combustion chamber is such a terrible thing - it's not. The burnt exhaust gas is inert, so by taking up space within the combustion chamber, it prevents a full usage of the space within. This space could've been filled with fresh intake charge. Since the gas is inert and fills up the space within, it keeps the combustion chamber's temperature lower. Lower temperatures result in two things: 1) lower oxides of nitrogen 2) less chances of detonation.

Detonation occurs when the cylinder pressures and temperatures are high. Since the EGR recirculates the burnt exhaust gas through and keeps the temps down, it lowers the detonation threshold. So why is it important to richen the a/f mixture? When the EGR is removed, the cylinder temps increase, increasing the detonation possibilities for two reasons: 1) detonation is most likely to occur where large amounts of torque is made in XXX rpm range 2) detonation occurs when the temps are high (as stated above). The Maxima engine makes a lot of torque in the 2000-3000 rpm range, so by removing the EGR system you're shooting yourself in the foot.

in summary, it's not worth it. the EGR is not active at wide open throttle or above 3000ish rpm. You will not find a performance gain by doing so."

 

I agree on what EGR system does but disagree on the conclusion. First of, EGR system is designed for emission purposes, not for cooling cylinders. As you mentioned it recirculates part of exhaust output back into intake. The gas is mostly inert and therefore doesnot mix with anything but rather serves as a placeholder or should I say a volume holder inside your combustion chabers. The less oxigen and nitrogen combustion chamber receives, the cooler it burns. The less oxigen and nitrogen combustion chamber receives the weaker the expansion and pressure on your pistons. Volume taken up by this inert gas renders the same effect as reduction in engine displacement. It is not a goal but a side effect of the EGR system that it cools off your combustion chambers. The heat itself is nothing to worry about as its insignificant compared with heat increase by introducing CAI or supercharger. Supercharged engines receive considerably more oxi/nitro into their chambers and still run just fine. Then there is always an overhead of maintaining the system that does pretty much nothing. EGR valves (especially vacuum activated) are prone to fail once in a while. No considerable performance gain but everything big consists of small things. Take out EGR and get those much needed 2 horses and may be 3 pounds of torque on low RPM band. Save money on expensive EGR system components replacement. In fact this is one of the cheapiest and easiest mod you can do to your Max.

 

I was told a breather really doesn't do too much but make a weird sound. I am not sure, its just what I heard.

Erik

 

This is incorrect. It is the goal of the EGR system to reduce peak combustion chamber temperatures because a cooler combustion chamber produces a smaller volume of NOX (Oxides of Nitrogen).

 

instead of corking the intake ports, can I just put a breather there also?

 

No you have to cork it. All air must be taken from the intake and flow through the airfilter. Also installing a breather after the choke will render your idle high. All ports in the intake after choke MUST be securely sealed. The only place for a breather is on the head port which leads to the PCV valve. Breather WITH filter is required there. NEVER seal head port or else you will increase a pressure inside the sump.

 

can someone tell me the correct size of the breather so it will fit?