Catch can and venting

[Dr HaxZaw]

Hey all

So i've bought a catch can to stop the oil having a party in the plenum and having read a few other threads on this forum i'm wondering a few things

Is it better for the can to vent to the atmosphere or for it to vent into the throttlebody?

The reason im asking is that i was thinking of closing off the port in the throttle body and then running the vent from the catch can into my airbox... mainly cause that way there wont be a little filter sitting in the middle of my engine bay and i cant see it being defected for that.
I assumed this way the engine should run a little better ive heard that it messes the engine up a little bit cause its gets a bit of extra air but the maf doesnt read it.

This is only an idea so let me know what you all think

[azkwazere]

Hey all

So i've bought a catch can to stop the oil having a party in the plenum and having read a few other threads on this forum i'm wondering a few things

Is it better for the can to vent to the atmosphere or for it to vent into the throttlebody?

The reason im asking is that i was thinking of closing off the port in the throttle body and then running the vent from the catch can into my airbox... mainly cause that way there wont be a little filter sitting in the middle of my engine bay and i cant see it being defected for that.
I assumed this way the engine should run a little better ive heard that it messes the engine up a little bit cause its gets a bit of extra air but the maf doesnt read it.

This is only an idea so let me know what you all think

Its illegal to vent to atmosphere hence the best option is to plumb it back into your TB.

aZk.

[Jesterarts]

Hmmmm...

It's definately illegal to vent it to the atmosphere so that's ruled out.

One thing though, my catch can vent is plumbed in so it enters the manifold AFTER the TB so under VAC. If you plumb it in to the airbox, then it won't be much vac.

Not sure how this would affect things. I just thought I would post this as an observation and let others fill in the blanks.

Cheers.

[ToMMMaY]

alot of people vent it to the atmosphere instead of using a filter use a hose to hide it underneath your car.

[Dr HaxZaw]

alot of people vent it to the atmosphere instead of using a filter use a hose to hide it underneath your car.

i was just going to run the hose into the airbox and put a filter on the end of it... and i thought the only reason you couldnt vent to atmosphere was cause of the filter catching fire (kinda like an exposed pod filter)

One thing though, my catch can vent is plumbed in so it enters the manifold AFTER the TB so under VAC. If you plumb it in to the airbox, then it won't be much vac.

does it need to be under vac or not? i assumed that the breather on the block was just there to stop crank case pressure so whether it was under vac wouldnt make a difference

I think delcowizzid had a pretty good idea about what was going on but it never made sense to me