I don't think you'll find any documentation.
You will, however, be quicker. The stiffer springs will help keep some sort of contact patch on the outside front, and the valving/springs will help you transition. It probably won't be huge, since the BAT kit is a mild stiffening, but it will be measureable.
Why would you want to modify the car? If you're concerned about class placement, the BAT kit isn't going to get you anywhere near competitive, and will boot you out of GS if you're there now. If you just want something more fun to autocross, and your driving is pretty solid... Well, that's a whole 'nother can of worms.
