Alloy Inlet Nipple........what Goes On It?

[Friggerpants]

FItted a Alloy inlet and 52mm Throttle body on my S2 ELise today (Plus decat!)

 

Anyway, noticed there's a nipple with nothing attached to it.........I've just blanked it for now.

 

Looking at this picture below theres a red hose! WHere does that go/lead to on a 111s?

 

[Alex B]

 

This is blanked on mine, have noticed any running issues due to it being blanked.

[un1eash]

It goes to a vacuum vessel that controls the value on the 111S drivers side exhaust tail pipe.