the eibach kits a progressive so they should not bottom out, I wouldn't try speed bumps at 55, but you should be o.k.

 

^ So are the sprints that are on my 94 altima and if you push it hard enough and I mean damn hard (which i tend to do once and a while) you can hit the bumpstops. what you have to remember is that stiffest is not always best when it comes to spring setups a lot of times a softer spring and more travel will give you much better handleing (gotta think within reason here). If I could do it all over on my altima I would get springs that drop it 1.2" instead of the 2" I have now. There is one bonus of my car being that low, the car looks damn mean with its flat black rims.