The factory 16:1 box should be ~3.5 turns lock to lock, the Borgeson box should be just over 3 turns lock to lock as it's supposed to be 14:1.
If you're currently at 2.5 turns lock to lock that would mean the rack is about 11.5:1 all things being equal. But the distance lock to lock may not be the same for them, which would mean it's not a straight ratio like I'm using to do the math. I know one of the complaints about the racks is that in this application they allow for less steering angle. I thought most of them were 12:1, but I could be wrong.