I was curious as to why the vacuum pump had 2 ports.
I found this on the web, which explains all.
Exhaust flap valve...I guess on a cross pipe linking the LH and RHS exhausts, the flap will close when in sport mode, or something. Any BMW expert here?
This is the front of the engine in an Aero chassis, the pump is upper left.
Complicated, isn't it?
Not at all surprised the bonnet, front bodywork and O/S wing had to come off.
