Maximum tire width

So I am turning my daily 325ci into a track car slowly but surely. Im going slow because im trying to buy strickly good parts. Now I have stock suspension and was wondering how wide of a wheel setup I can fit on my car with those demensions? after I get wide rubber on the car I was thinking of getting these coilovers if it helps. http://ift.tt/1CWiPsF





any body that can help give reviews is welcome. if you have a track car feel free to let me know what you have as well, and how you like it.