large vac line from LIM to Y-pipe what\'s it do?

[Aubec]

Hi guys, I\'m in the middle of going single (at the "putting it all together again" stage and am just trying to work out the vac plumbing I need.

On the twins there is a line that runs from the Y-pipe (so a source of pressure) to the LIM - its the Yellow line just above the "J" on the diagram.  It must be pushing pressurised air straight into the LIM, bypassing the throttle.  What does it do?  Do I need it?

[jackaleks]

pretty sure you can just junk everything apart from the stuff on the orange line (fuel purge), PCV line and double throttle (if you still have it)?

i remember looking at that yellow vac line when i simplified my twins and not seeing the point of it!

[Jit]

Cant see the diagram but isnt there a line around that area thats "supposed" to help fuel atomization?

[SiH]

Cant see the diagram but isnt there a line around that area thats "supposed" to help fuel atomization?

Yup, it\'s the inejctor atomization line I left mine open to atmosphere when I went single, but then got constantly bullied about it by a very knowledgeable dude until I finally blocked it off :o

[Aubec]

Maybe I\'m dense, but is atomisation of the fuel not quite important?  More important perhaps with mahooooooosive ID2000 injectors?

If its just a case of a bit of vac tubing from post turbo, pre intercooler, I think I might just keep it in use!

Surely open to atmosphere would leak boost?

[jackaleks]

bit of info from the \'merkins

turns out it only helps fuel atomisation at idle (supposedly).

[RXSpeedy]

Im pretty sure mine is plumbed back in after the air filter but before the turbo inlet along with the Oil squirter vac line. I just used the single turbo diagram similar to the twins diagram you posted.