In an N/A application, it doesn't matter because all the pressures are constant between in the inside and outside of the engine.



When you add boost, there is significantly more pressure in the crankcase that is not helping anything. It has to go somewhere. If you cap it, you will get oil-blow-by into your intake system.



That's not a good thing. It makes the intercooler full of oil, the throttlebody full of oil, the intake manifold full of oil, etc.



Another added BAD-Benefit from Blow-by is that you will effectively lower the octane rating of your fuel, making you that much more likely for detonation.



So, in a Boosted application, you do want the Oil Filler Necks to be vented into the atmosphere to keep the crankcase pressures down. Unfortunately, that may mean that you also get oil blown out of them in high boost situations.



The Solution?



Put a small K&N on the neck of the filter will usually work for 12 PSI or so.

More boost, and you should run a VENTED Catch can from the filler neck.

Jaz has a real nice one that I need to run a line to.

 

ok guys, ran into a problem. the main pulley nut is a biotch... should i just try and wedge something into the flywheel to stop it from turning? or will that hurt something?

 

Thanks DF.

 

If the engine is out of the car, use the front crossmember with some clutch bolts and a tranny mount bolt. Put the crossmember aross the flywheel and secure it with a clutch bolt or two, and then use the tranny mount bolt in the engine housing where the tranny would bolt up. I did that to remove the flywheel nut with an impact wrench and it held just fine, so it should be good for you to loosen the front pully nut.



Hopefully youve read and or know about the bearing problems that can be associated with taking off the main pully? Theres an article at Mazda Trix about it if youre not sure about what Im talking about.



~T.J.

 

this is for my gsl-se front cover, i'm not reusing this block cause its in pretty bad condition so i'll be alright as far as that goes. a buddy of mine who's knowledgeable about TII's is gonna help me swap the front cover over after i get it tapped and everything so maybe about a week or two and this thing might actually be running, we'll see though...

 

Directfreak, thanks for the link. Right now venting to the atmosphere means I get an oil spray from it onto the engine, hard to keep clean. Catch can sounds like a good idea. I wish this thread was around when i plugged my vents. The exhaust started smoking like a chimney and I thought for sure my turbo went kaput. It is not a big deal in n/a applications but I am sure it will have long term effects even though they are not immediately apparent.

 

Unfortunately, you probably took some years off of the Turbo oil seals. Oh well. It's always a learning process.



Welcome to the NP forum. How many lbs of boost are you running? Did you build your Turbo FB, or were you fortunate enough (smart enough) to buy it off someone?



I am interested to know about your Torsen rear.



Oh, and as a new member, you are required to post pics of your

car and set-up.



Right guys?!

 

Yup no get posting. Directfreak will any container work for a catch can as long as the line gets to it???

 

I think Steve (AJC-13B) used a 20oz sprite bottle at one time for his catch can so yeah, any container will work. Just make sure it's vented. I don't have a catch can on mine, I get a couple drops out of the line running to the ground per few hrs of run time. The overflow stuff that comes out of mine almost smells like straight gas. for a while there when tuning my oil level actually went up! All that extra gas started to seep it's way into my oil system. Now that I have it tuned pretty well (still have some minor issues to work out) the oil level stays the same and only has a slight fuel smell to it

 

Setzep already answered, but pretty much any will work as long as is it's not sealed.