What does this vacuum line go to?

[97AutoXVette]

My question is in regards to the vacuum/boost line located towards the inlet side of the blower. The small one between the master cylinder vacuum line and the boost bypass valve line which snakes over/around the fuel lines (seen in picture). What does this lead to? Does the ECU read from this? Does the boost gauge on the dash read from this? Why do some owners cap that off and eliminate that line?

Thanks for the help!

 

[Scottydoggs]

that powers the climate control. the small vac line up top. it runs to the firewall then down the fender into a wire harness into the cab of the car.

boost is read from the map sensor.

 

[97AutoXVette]

Nice, thanks for the help. Two follow up questions:

1) If I cap off that vacuum line running into the firewall, what will happen differently? Will the climate control not work correctly? Not sure how a vacuum line would function with the climate control.

2) Where is the MAP sensor located? just in front of the boost bypass valve? (I see a vacuum line running from the valve into a sensor I believe).

 

[Scottydoggs]

if you cap that off the air flow will not work, like you cant change from vent to defrost or flow or any combo offered. it will only come out where ever it wants to with no vacuum to power the vac pumps in the dash.


vac line routing. pic says a 1000 words.

 

[Scottydoggs]

i just came across your other thread on the vac line. if its falling off. go buy 2 inches of new vac line, i bet they dont charge you. (its a buck a foot) then with a sharp razor cut the old hard end off the plastic line, then push the new vac line on the plastic line then onto the tree on the supercharger.

 

[97AutoXVette]

Actually I miss-typed the header in that other post. It is not coming off, just was trying to ask the same question I posed in this thread. Thanks for the diagram above!