Crank Case Ventilation

[Tim9]

Hi,

I was reading an article on generally turbocharging a NA motor and it talks about always having to modify the oil breather system to stop boost getting pushed into the sump, but I don't see it mentioned anywhere in the installs.

Does this need to be done on J-spec or US spec cars?


Thanks

[LexusFTW]

The passenger side valve cover pulls from before the turbo anyways so all it sees is vacuum. There's a one way check valve on the drivers side valve cover so boost wont pressure the sump.

[p5150]

For my PCV system, I took a 1/2" pipe tap and tapped out the breather holes on the valve covers for a 90 degree barb/1/2" NPT fitting. The hoses from each valve cover run to a catch can. The outlet of the catchcan runs to the intake pipe in front of the turbo inlet so that it sees a very consistent vacuum that is somewhat relative to the air intake rate of the engine.

I think that the stock PCV system is inadequate; it wasnt designed for a turbocharged application. Higher power levels are a result of greater cylinder pressure and will give more blowby. Larger hoses help vent the crankcase better and ensure that you dont push out your main crank or cam seals when you really turn up the boost. It also helps keep your oil clean.

[tuning haus]

p5150- i've seen numerous higher horsepowered supras running this set up you just spoke of. it loks pretty cool too.. any pictures of your set up you can post?

i've talked to a mustang guy too and it seems the domestics use a pump to suck the oil out to further enhance the effect. i guess that's the way you really do it!!

i've seen supra guys putting the fitting/lines coming from the valve covers into the exhaust/down pipe as well. they have told me it acts almost like a suction and it sucks the oil out and through the tail pipe. ? :)

[Gunnar]

i've talked to a mustang guy too and it seems the domestics use a pump to suck the oil out to further enhance the effect. i guess that's the way you really do it!!

The evac system, I've heard on some domestics it's good for a decent whp gain (but I've never looked into it to be able to say either way).

[Dramon]

I have a friend who uses an evac system. Works pretty well for him, no dyno comparisons, but its a lot cleaner and more simple than having a bazillion lines for your oil catch can going everywhere.

[SecretSC]

I've been running the crankcase evac setup for about 2 years now. It works great. It eliminates the whole catch can and oil in the intake problems, less plumbing in the engine bay too.


gadgetSC

[Gunnar]

I've been running the crankcase evac setup for about 2 years now. It works great. It eliminates the whole catch can and oil in the intake problems, less plumbing in the engine bay too.


gadgetSC

I'd be interested to know more about this. At my work we carry both Moroso and Mr. Gasket evac systems and they're both a lot cheaper than a nice catch can setup.

[LexusFTW]

Heres how mine is set up.

http://www.clubna-t.com/forums/showthread.php?t=4282

[Gunnar]

Oh okay! I saw that thread on SF and wasn't aware what the stuff going into the downpipe was. :) I've been looking at pictures of the evac systems we have at work and I guess I didn't put two and two together. Did you notice any gains switching to that setup?