So what'd be a venturi exhaust then? Our downpipe with a cone shaped restriction welded into it?

 

Its basically something like this. There's enough info online for it, but basically flow rate draws the gasses into the exhaust rather than the back pressure pushing back up into the line.

 

is that what this does?

http://urgedesigns.com/?page_id=1076

 

C'mon guys. Just add another turbo and instead of boost, create lots of vacuum - problem solved!!

 

Oh, and dont get me wrong. Im not saying theres anything wrong running the vent lines back to the intake. It does have its benefits of keeping things clean and providing at least some draw on the crankcase. Its just not this mega vacuum effect these companies claim it is with magical results.

 

It certainly helps if you have a turbo that is overly sensitive to crankcase pressure.

But I think running a proper side intake negates it mostly. You shouldn't have very much vacuum in the intake pipe. More than a few inches and you should probably addressing the size of the intake and filter.

 

couldn't you get the venturi effect in the intake hose? I mean the air is already accelerating in that conical tubing. my CCV fitting extends a tiny bit into the hose
there are brake bleeders that use air pressure/flow that effectively creates vacuum

 

a friend of mine installed that venturi in the exhaust of his e8, running 2.3 and fp black, measured the crankcase pressure and the overall effect was minor at best...

 

 

I dont think your getting the sort of velocities you expect in the intake. not like the exhaust which would have decent pressure through it.

 

from what I understand its the compression of the same volume of air that increases the velocity and reduces pressure and therefore creates a pressure differential that causes the pull (vacuum) towards the lower pressure area. the intake hose has the cone shape that would probably achieve the same effect of a carburator venturi (which pulls fuel from a reservoir).
the exhaust pipe diameter after the turbo is constant so that might not even work

 

Are summer projects ok in here? Lol

 

should we start a place is not dead sup with them summer projects thread?


Got my motor out on the weekend. Pulled the head off needs exhaust valve sorted as its leaking.

This weeks mission is to get the bottom end off and throw a set of big ends and mains at it. bores look perfect so wont touch rings.

Other jobs just chuck standard stuff at it eg head gasket and cambelt kit etc.

 

So jelly, right now.

 

thats uhhh.... ummm... an ebay aircon pump