There was comment on lekrut's enquiry thread re the catch can.
I didnt want to hijack that thread - so I regurged an older one instead....
Here's a plug from needswings website...
here
Why would we need such a part?
The 2 smaller (one on each bank) valve cover ports feeding into the bottom of the throttle body are pulling oil into the intake stream thru the venturi port on the bottom of the throttle body. This is coating everything after the throttle body with oil. For those of you that have looked at the inside of your intercooler, air distribution ypipe or intake manifolds will know what we are referring to. This oil coating is causing inefficiency to the cooling and flow thru the intercooler and hinders flow thru the ypipe and manifolds. The spark plugs will eventually foul as well due to this oil. The IAT and MAP sensor get coated with the oil, and the oil also makes its way into the combustion chamber. In short, its crud and we don't want it.
I'm interested to now how much (or if similar) oil people are picking up in their cans (as per harbor's #3 post) and if they've noticed any differences in residue build up with and wthout the can.
Particularly in the CAC and IAT/MAP tips.
For those with a sense of humour.....
From Harbors #3 Post
3,600 miles at avg. 30mph = 120hrs
120hrs at avg. 2,500rpm (~184cfm) = 100,000lbs of air
oil "catched".....~3 oz (100ml, 80g) of oil in 100,000 lbs (45,000,000 grms) of air = ~2 parts per million (ppm)