Petrorabbit's first posting seems to include an error in the units. 60kmph ????
It should be either mph or kph. 60kph is about 38mph and the Z would do that in first gear at just under 7000rpm on standard gearing, reaching about 55mph in 1st gear at 9500rpm.
With a 16T front sprocket, 9500rpm will give you just under 60mph.