it depends on what model z3 you have. some can go to 130mm, some cant. im no expert, so i cant say what specific models can and cant.
to find out youd need to rip the fork apart(or have a shop do it for you....then again, a shop should know without ripping it apart). basically, if your fork has 20mm top out springs then your stuck at 100mm....if it has 50mm top out springs, then you can buy a 130mm spring kit to get 130mm.
ive got a z3 flylight 100, running coils......i could go to 130mm, as i have 50mm top out springs.....but it would probably throw my geometry off wack.