I think 1.6 incorporated some more realistic values, but if you still want to manually define your own you can do this :
Create a .cfg file in the Nolimits directory.
Edit the file, paste these entries in and edit them accordingly.
sim.vertg.posyellowlimit = 5.0
sim.vertg.posredlimit = 6.7
sim.vertg.negyellowlimit = -1.1
sim.vertg.negredlimit = -1.8
sim.latg.yellowlimit = 1.2
sim.latg.redlimit = 1.8
sim.accg.yellowlimit = 2.0
sim.accg.redlimit = 3.0
I can't remember if you need a specific file name for it, but try something like config.cfg or nolimits.cfg to see if they work.