Sorry for the noob question. I have an idea of what vacuum is but I'm not sure what the vacuum lines do when they're connected to things like the BOV, or wastegate, etc... Can anyone tell me what they're for? Thanks.

PS, I did a search and found lots of posts about vacuum lines. But most of them are only about where to T off, or what kinda lines to use.

 

Basically, they let the BOV, wastegate and other devices know when the car is in vacuum or boost and how much and when to open up or release. Boost or vacuum pressure travels through the lines from the intake manifold and mechanically gives a "signal" to whatever device they are connected to.