Davey , w 15 " rims , I`m not sure you can cut one coil...
I had 25 1/4" between fender opening and ground w my 14" rims, cut one coil (of course , I`m not sure what type or which stiffness springs I had)and its now 23 1/4" (and I have about two fingers +_1.5" between tire and opening when car sits empty, have not checked w/ me (185lbs) in the car....need another person to measure..lol), the rear was and still is at 24".....
it also depends on your tire pressure to some degree...