I meant the size of the feed. those chinese turbos have smaller center sections and don't need as much oil as a borg if you're running a -4 feed. You may need a restrictor.

 

The pressure doesn't need any help to get out of the crankcase. The only reason to route fumes to the intake is for pollution control, crankcase fumes are full of unburnt fuel. Prior to 1968, valve covers were vented to the atmosphere.
A vacuum pump will evacuate the crankcase and negative pressure in the crankcase helps the rings seal. I have always thought that having a vacuum pump would make oil mist collection more efficient, but I can't quite envision a system designed for maximum oil collection. Maybe the exhaust from a vacuum pump will improve the action of a centrifugal oil separator.
It would be nice to have an oil separating system that is efficient enough to allow you to send the fumes back to the intake, 100% oil free. You would never have the smell.

 

Now that's an idea... any way a restrictor could hurt? Reading the forums I don't see a lot of mention on turbo restrictors, I see them mentioned quite a bit in the import world though.

Ok that makes sense. I plugged the turbo inlet elbow and I rigged up a little breather filter off a piece of 3/8" hose. I'll put some miles on this and make an assessment in a few days before considering doing 1 vented breather tank for both valve covers.

So to confirm, check valves are only necessary on MAF setups correct?

 

restrictors are quite common. read on tech

 

Restrictors are common mostly for ball bearing turbos... I'm sure a lot of those import guys run bb turbos so that's why you've read a lot about that.

 

On my Maf tune setup, I capped the intake line on top of the intake manifold and put two breathers on each valve cover and one on the oil cap... Never had a problem or oil smell... Every months or so I'll clean the valve cover filters, because they get a little messy.

 

Ha, restrictors, I ran a freaking -6an to my turbo just to keep it happy



(BB turbos do need restrictors usually though)

 

did you have low oil pressure or something? -6 is huge. Last I checked yours was just a standard 400

 

No not always necessary. To much restriction and you will smoke the bushing in side if it's s JB turbo.
Depending on turbo they could already be restricted.
Look down the turbos oil inlet prior to installing the inlet fitting. There's should be a very small hole in the actual casting.

Now the drain needs to -10 or larger.

Simple way to build a restrictor is using nitrous jets.

 

Several big turbos we sent out recommended -6 feed with a min -12an drain.