Hi ibnahmed, I have some more experiences to share now (but not on the turbo, unfortunately, I am very anxious to see how that is going to work out for you). I have been through a few re-installations and I realise I have forgotten a thing or two: about the audio, I forgot to mention that I have installed that patched 2.87, but it does not contain the preferences panel etc. that you need to activate the on board audio as opposed to some HDMI. So I install the official 2.8.8 for that, and manually remove the voodoohda.kext after that.
With respect to the memory, I got me some more, and then it went wrong for a while. For future readers: I have installed 96GB in the 12 available slots on the Z620. If I declare all of them in Clover Configurator or the config.plist as discussed before, the computer only sees 80GB, it has two banks missing. Surprise, surprise: the computer sees all 96GB if I set slotcount to 16 (even though there are only twelve, and the declared DIMMs are stated to be in slots 0-11).
Now, I am fiddling to get some kind of dual boot with windows working properly, next on the agenda after that is probably the turbo stuff. Good luck!