I have the quick ratio 15:1 rack and pinion.
I bought mine from steeda. It does just what it says. It allows you to turn the wheel from lock to lock with less degrees of turning. I replaced mine cause I was replacing the power steering pump. Two things I suggest for anyone who installs one is to make sure you use the suppied o-rings for the hard lines going to it (i'm not sure if I installed mine or not), and install the hard lines on the rack before you bolt up the rack to the k-member. If you try and put the hard lines on after you bolt up the rack to the k-member you will have no room to get a wrench on the fitting and you will probly be lazy and only put it on hand tight or cross tread it. There is NO ROOM around the fittings after it's bolted to the k-member. Mine leaked after I installed it. cause it was cross threaded and then I took everything off and put the hardlines on with it off the car and then it was good to go after I put it on AND used lucas power steering stop leak on it.