If you shorten the top link, in other words, make the front lower and the back higher, drop the rippers down, it will dig in well and tear it up. If you have a bouncing problem at first, add some weight somehow, maybe concrete blocks.
Once you're gotten a start into it, it should start to tear it up good. Later, you'll want to readjust the top link so that you can get the rear inside blade to grab a box of dirt for redistribution.
John