Quote:
Originally Posted by XwChriswX
Can some of the guys that have done this think back and write up a DIY for those that would like to do this, but don't wanna cut/swap the wrong hoses to the wrong spots and making something simple a big problem?  |
I posted a DIY when I did mine, over here:
DIY - Oil Catch Can (w/ M370 + Batt Reloc). Mine's specific to my setup though (M370 intake manifold, and an empty battery compartment as a convenient location - may as well use the battery compartment heat shielding to promote vapor condensation in the can), but there's some general notes and ideas there too if you read through it.
All in all, doing your own catch can install is pretty simple once you understand where things hook up, you just have to decide where and how you'll mount/attach it.
Quote:
Originally Posted by Nixlimited
No cons other than extra connections and a marginal amount of extra weight and space needed. Pros are less oil coating the intake tract as well as the fact that the vapor that is burnt off in the combustion chamber allegedly lowers your effective octane rating i.e. tends to promote detonation. That's what I was told at least on my old STI. I would be very surprised, however, if NA cars collected the same amount of oil as FI cars. The increased pressure of the FI tends to cause more blowby and more junk ending up in the intake tract. With that said, factory turbo cars come without catch cans so it may be overkill.
Note: I also had two lines on my STI and I ran twin cans rather than 1.
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I would think in general you'd be right about FI getting more blow-by, seems to make intuitive sense. But that just puts more blow-by into the crankcase, which is mostly fuel vapor. From there you're venting the crankcase through the PCV valve, and the crankcase shouldn't be at abnormal pressure, and most of the rest of the vapor is oil vapor from there. It may be that the rate of catch can condensation is mostly driven by crankcase pressure/airflow, which shouldn't vary much for FI vs NA.