Trunk Torsion Bar Adjustment

I'm looking to increase the amount of "lift" so my trunk will stay open. It has a heavy spoiler on it now. I see that there are three slots on each side of the hinge. Currently, the torsion bar is in the slot that is closest to the rear of the car. Is this the "maximum" setting? If not, are there any tricks/suggestions for moving it?
Thanks, Bill