What's the function of the Venturi Tube on a Tiptronic?

[78F350]

Originally Posted by The Radium King

so the venturi tube ties in to #12 and #14 here (why i don't have these on my car):

No, I don't think it ties to 12 or 14.

If this is for the brake booster, why did they do it this way on the Tiptronic cars? Do they require more vacuum? Why run all the way across the engine like they did? How does the engine compensate for the extra vacuum?

Good questions. My guess on why it runs the way it does on the Tiptronic is that the right rear intake manifold is closer to where it taps the intake tube vacuum. I can't make a good guess why it uses more vacuum though. Maybe it's only significant at lower rpm for braking at idle as Radium suggested.