Originally Posted by
Däs Schmoo
So how do the pressures relieve themselves when boost pressure is present?
You would be surprised at how high the crankcase pressure can get and it doesn't need anything but a place to go to remove itself from the crankcase.
On another note, vacuum pressure draws those nasty gases back into the engine to gunk things up and burn in the combustion chamber.
running it to the ground is better then nothing, but you can't argue that an added vacuum will not improve its performance. thats why people spend so much on air vacuum pumps JUST for their pcv system.
for boosted apps i recommend a two vac source setup. a friend and i came up with a pretty solid design with two vac sources. a slash cut in the exhaust for high load/boost times,(under light load, a slash cut provides next to NO vacuum.) and the IM for low load/vac times. check valves in each vac source line to prevent positive pressure going into pcv system.
i don't like running a slashcut in preturbo intake because then your running the junk through your turbo decreasing its life.
as you know, stock honda system uses IM as a vac source and just reburns all the vapor and oils, no harm done. if your concerned you can add a small inline filter on the IM vac source line.
here's a pic
das das schmoo aprooove? haha
-Luke