V8 variable stage inlet vacuum concern...?

[Super Ron]

I have a 2001 Audi S6 with the 4.2 40v V8 ANK engine with the internal flaps on the inlet, giving better torque throughout the rev range, like so



Whilst replacing some vacuum pipes elsewhere and i found something that i don't think is quite right. I looked it up and this is how it should be. Blue is vacuum from the inlet to both solenoids, then one solenoid opens the line up for one flap arm in red and the other solenoid opens up for the other flap in green.



Mine however is plumbed in so both flap plungers are run off one solenoid in red. Then the other solenoid opens a flap in the airbox to let 'hot air' into the airbox, in brown.



this is where the brown feed goes



Is this correct? As it is i haven't got a 3 stage inlet i only have a 2, surely? there are no extra plugs for a solenoid that i can see, and no spare solenoids? what should power this flap in the airbox? As i see it, it should be piped up as the top diagram and the airbox flap should come from elsewhere? or is this a different setup where it is only a 2 stage inlet?

Any help greatly received

 

[DGSdale]

Have you not got a diagram for the air box from the same source as the two diagrams you're showing us? What does that show? I have a 3.0 A6, same engine as your previous A4. Very similar (the same?) set up for the inlet manifold. I'll try to find some time to study it tomorrow. Might be of some help.

 

[Super Ron]

yep already checked the airbox diagram for the 4.2 and theres nothing showing, nor i could find on any other airboxes



the 3.0's deffo share one solenoid as the two diaphragms help each other turn the centre spindle, shown here



but i'm let to beleive the 4.2's work independently. it is currently plumbed in as the 3.0 above.