I know that the oil catch can is suppose to catch the oil coming out of the valve cover into the intake pipe to the turbo. Isn't there a purpose for the oem design for that? Doesn't the turbo itself needs to be lubricate by the oil??? I know with the catch can, it help keep the turbo clean and all but isn't that bad for the turbo too?

 

Turbo has an oil return and feed line for lubrication. Wow. All that oil from the crankcase to intake is mess up maf readings and decrease intercooler efficiency

 

I will give you as much info as I can, but as an evolved member... you couldnt find this after a search? There are a few REALLY good catch can articles on here and I even started one with some decent info in it...

You do not want any oil in the air passage at all. It should only be air at all times because otherwise the octane rating falls blah blah gunk in the motor blah blah BAD. The turbo itself has its own oil lines that keep it lubricated. You need a dual catch can (Saikou-Michi DC3 is great) to actually filter all oil from the crankcase that is usually dumped into the intakes and eventually everything else in line.