You won't believe this...
I have a slight clutch slipping problem if the turbo came in hard (and it was only 7 psi) on the track last friday.
Pulled the engine (again...) and found a dry bell housing behind the flywheel.
So I looked at the clutch disk more closely:
Indeed: the springs hit the flywheel and caused some part/not-engaging on one side...
I probably got punished for using a VW disk with a G50 center which also gives the G50 springs (?) (although Kennedy should have known this too I suppose)....who else is crazy enough to try this huh?
Problem probably easily solved by turning down the inner part of the flywheel a bit to clear the height