What is it
 

Hello mini fans....can’t find this info anywhere in my Haynes repair manual
working on the dreaded timing chain replacement for a friends 2008 Mini Cooper S and has a turbo... question ... what is the device driven off the exhaust camshaft ? Not the VANOS.... the other end. I believe the intake camshaft drives the fuel pump but the exhaust has a round looking silver cover. Upon removal of 4 torks bit fasteners just looks like a flat bar inserted into a slot and to half moon shape wedges, my guess it that it either makes vacuum or pressure ? Anyone have a clue
https://cimg2.ibsrv.net/gimg/minicoo...0ee387c086.jpg
Looks like this
https://cimg0.ibsrv.net/gimg/minicoo...f4cf07a929.jpg
Second photo