Just done a 1 wheel up test on my Freelander (2003 TD4, 142000 miles); warm weather, VCU at ambient temperature.
14 lb sledgehammer on a 1.6m bar (equivalent to 8.5 kg at 1.2m) - took 12.3 seconds, very much in line with Hippo's graph (and Celt69's time for a new VCU lies on the curve too)...