NZ951

What would be the point of have a filtered open recirculating can. LMAO

M Danger

He Special, any thoughts on how this might relate for me since im getting smoke on decel only?
Both head and turbo with about 5k on them from Powehaus, the PO was running about 20lbs of boost

Geneqco

Hey Special Tool,

Is there a particular one you can suggest that works well... or am i better off modiying the LR one (since I already have it). If using the LR one, I guess I'd just fit a pipe to the top in place of the filter. If so, what diameter would you suggest. My AOS has not een drilled but has been enlarged with a soldering iron.

Thanks

eniac

Since I removed everything in front of my turbo except a filter, there is no way for me to route an AOS line back into the intake. Instead I installed a generic breather filter on a small hose coming off the top of the AOS. After 2 months of testing this method out I have seen MUCH less oil in my intercooler pipes and less smoke out the tail pipe. I typically run 23psi for normal street driving and 27psi when I feel like going fast . I don't really see the need for a catch can unless your pulling with vacuum back into the intake.

95ONE

Just put my setup back together. I've been playing with this problem for a couple of days now, experimenting in every way. I have to side with Tool. (Why wouldn't I, I'm sure he's already done all this)
But.. I didn't see anyone mention that little aluminum reducer in the vacuum line. what's that about?

Rogue_Ant

What turbo, and on what fuel?



Rogue

special tool

uh-oh - this is not really a symptom of the case.
What color is the smoke?

eniac

60-1 turbo and C16

M Danger

its blue-grey. Was thinking maybe a valve seal popped off, then came across this thread...

LFA951

I have the same setup, drilled the hole bigger, bought a curved 3/4" hose designed to curve at the port and come straight up behind the intake manifold and put a 2" generic breather on top, only drawback is that it spits out a little oil under heavy acceleration around the oil filler cap where it's near, but other than that, my plugs don't get bathed in oil anymore, and my pipes and intake throttle body have also much less oil in them, and I'm not blowing out as much smoke through the exhaust, since there is oil oil going into the coldside impellers...

M Danger

Hey Special any thoughts?

M Danger

bump

TurboTommy

eniac and LFA951;
I'm doing the same thing.
However the the odd, odd time, I do have oil smoke coming from my exhaust. It's very seldom; notice it only at idle, maybe, after some spirited throttle or after restarting the car. I know why it's doing it (possible lack of turbo drain capability), so I'm not alarmed and just ignore it.

Having said that; as for Porsche's stock setup, I would question if it's purpose is to drain the turbo. I think it's for emissions reasons to recirculate the crankcase vapours. Besides, by routing it upstream of the turbo compressor, how much vacuum is being generated, really. Nowadays, with our free flowing air filters and MAFs, air is taking the path of least resistance and there's very little "pulling" from the crankcase. Also, even if there was a vacuum being generated, wouldn't it only be when the turbo is really spinning? All the other times, when the turbo isn't producing any boost, I cant see there being any vacuum in front of the turbo. During these times the engine is still running and there's a certain amount of blowby that would need to be vented. So what about that?
Also, if there actually is vacuum between the air filter/air flow measuring device and the turbo, you could argue that it's comprimising power output because the turbo is seeing less than ambient pressure.

Getting back to my case; I have a bigger engine and running more boost. So, perhaps the stock venting size is not big enough. I have since rectified this and we will see if I still get a smoking turbo the odd time.

I would state that air always goes from a high pressure zone to low pressure. So, if you have crankcase pressure it should still vent to atmosphere, because ambient is still lower pressure than the crankcase. Providing, of course, there is enough "room" for this pressure differential to flow, I wouldn't think you actually need a "vacuum".

I'm eagerly awaiting a rebuttal to tell me if I'm seeing this wrong.

zoltan944

the crankcase wants to vent most under pressure. under high throttle you have no vaccuum in fact you have boost only. It is vented to the intake manifold for emissions and a zero maintenance system. under a stock system you are only venting off throttle at vaccuum pull.
A vented catchcan is the best solution. Great way to stop oil from coating our motor.

eniac

This is pretty much how I see it. If equalizing with atmosphere pressure is too much for your crankcase and you need vacuum to prevent blow-by then you have much larger issues that will need to be dealt with.