Assuming that its the adjustable dampening screw your talking about it should have either 22 or 24 (cant remember exactly but look up spec on spax website) points of adjustment.
Screw it all the way to super soft then count ten clicks, should now be 'normal'. Then simply push down your car i.e sit in boot or push on wings and adjust acordingly to your taste, you will know when it feels right for you, mine feels firm and I think its on either 13 or 14 but can get a little rough. I also run my rear harder than the front, no idea why... just do lol. Just make sure you put both side to the same level though and take her for a long ish run before adjusting so you know exactly how you want to adjust (unless its stupidly obvious)
Also if your fronts will need one of these to adjust with in theory (or a spanner lol) and you do it on the top mounts, it makes sense when you look
