Oil Catch Can.. Is one enough?

[AdamW]

Ok from previous posts I know an oil catch can is recommended if you have had a few mods and give your car a bit of chop..

Have been doing some reading on the Perrin web site and now I find out there are three possible applications for oil catch cans...

Is it worth while having more than one oil catch can? If not what’s the best option for installing one?

1- PCV System
2- Crank Case Vent
3- Valve Cover Vents

http://www.perrinperformance.com/products/show/56/Oil-Catch-Can-Overflow-Tank?category=4&model=10
Subsection “Charts”

[senator]

i am sure a single catch can set up can do the job for the PCV System, Crank Case Vent and Valve Cover Vents.

[AdamW]

I think they draw air through the different parts of the engine at different times..

Ie.. PCV System works only when car is a idle or cruising (PCV valve closes off under boost).. If you join the theee systems together it might cause some unwanted pressure variances within the different parts of the engine.. I messed with my PCV on my last car and ended up loosing so much oil..

Valve Cover Vent System (cruise and idle)
Under idle and cruise conditions, the PCV system is pulling vacuum (more like creating flow) on the block. In this state, the valve cover vents allow for fresh air (from the intake system) to be sucked into the block back through the intake system. The best way to think of this is, they’re a fresh air duct for the PCV system. In this mode there is no downfall to how the system works.

Valve Cover Vent System (Boost)
When the PCV valve closes off under boost, the vale cover vent job completely changes. Instead of letting fresh air from the intake system into the block, they are now letting the built up crank case pressure out! Because the valve cover vents hook up to the intake system, they see a slight amount of vacuum. This small amount of vacuum helps to evacuate the built up pressure in the crankcase. The down fall to this mode is that the oily mess gets sucked into the intake system. Which then gets into the turbo, intercooler plumbing and back into the engine. As described above, this is bad. Under racing conditions with high load cornering, oil flying around and sloshing into the heads, gets sucked out of the valve cover vents and into the intake system. Again putting oil into all the wrong places.
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[senator]

yep understand that.... but most catch cans will have three inlets and a single return.

[AdamW]

From what I gather from their web site there is more than one return hose that applies negative pressure to different parts of the engine at different times, if you join them all up to the one can, one line will be have positive pressure when it should be under vacuum or neutral & vice-versa, thus causing the oil inside your engine to end up in all sorts of places it shouldn't.. Maybe I am wrong, its sucks not being able to inspect the engine for myself..

[GTSPECB STI]

LOL Adam just do them all and then please post results and pics?

[AdamW]

LOL Adam just do them all and then please post results and pics?

I appreciate your enthusiasm lol.. But at $225 a piece and no actual performance gain I’d rather make sure it’s a worthwhile mod.. I am sure there are better mods I can spend the money on if more than one is not really necessary..

From Perrin "Thanks for your interest in PERRIN! You don't necessarily need to run more than one catch can, but it will help to make sure the least amount of oil gets into your intake. If you were running with just one catch can, I'd recommend connecting the catch can to the crankcase vent and the valve cover vent. That way you would get out most of the oil before it goes into your intake. If you have any more questions, let me know, thanks!"

[senator]

ever considered a dry sump setup............