I have recently bought a catch can (cheep one) as a can is a can, right?
after moding it a bit. ie: put stainless steel wool inside it and seperating the intake outake lines better. I've noticed the inlet and outlet hole sizes going into the can are greatly smaller than the pipes feeding into it.

example: think of it like a 10mm hose connecting to a 4mm hose via a reducer.

will this create back pressure or in anyway gona be a problum. bad for the engine?

cheers.

Why would you want to install a catch can..? Having one , it doesn’t make a scrap difference on performance unless you want to spruce your engine looks….

I dont think he asked 'Should I install a catch can'.

Hi_VoLtAgE - It won't create too much back pressure so dont be too concerned.

it keeps your IC clean

WRX46 - You really should only reply if you have a clue about what you're talking about.

As for the catch can, they're handy if you're running more than standard boost as Subaru engines do like to breathe a little. It does help performance as it keeps your intake system free of oil which can make you intercooler less efficient and it also lessens the chance of detonation.

Your catch can should have 12mm hose connectors. The two breathers on the cam covers are 12mm and the PCV is 16mm. If you're running 4mm emissions hose something is not right.

Search function is your friend:
http://www.perth-wrx.com/vb/showthre...ighlight=catch

http://www.perth-wrx.com/vb/showthre...ighlight=catch

cheers guys.

A catch can does not have a true performance improvement, it does do exactly what it is advertised to do. The main reason to run a catch can is to prevent oil from entering (if using or burning) your intake as well as everything on the way including the intercooler. The advantage of a catch can breather combo over just a breather, is that hot oil does not get sprayed all over your engine. Less oil in your intake means less chance for detonation. This set up also eliminates back pressure from the head created by blow by gasses if hardcore moods performed ..

What's your point?

The point is… if you like academic but, is not a high performance (hard core) engine and doesn’t use or burn any oil, a catch can would not improve any performance thus unnecessary engine clutter.

'True performance improvement', does this have anything to do with 'harder' shocks?

Everytime I read one of your posts I feel dumber.