New Shocks and Springs
My Mustang project for this spring (aside from the GT emblems!) was to improve the suspension on the car. I added Tokico D-Spec adjustable shocks/struts, and Steeda Sport springs. The front springs are 50% stiffer than the stock ones. The back ones are comparable to stock, although they're progressive rather than linear. The springs lower the car about 1", and help even up the "high rear end" that's always bugged me. Why does almost all modern automotive styling include a rise in the body line towards the rear end? The shocks/struts are adjustable through a complete range of "firm" to "soft".
I probably need to take the car out to a road course and put it through its paces to really get it dialed in, but I found that a shock setting of 3 turns from full firm in front, and 3 1/2 turns in the rear provides a pretty good ride. I was really blown away by how much tighter the car feels. I feel more comfortable taking turns faster, and the front doesn't rise under acceleration as much anymore.
The only downside is that now I'll have to get an adjustable Panhard bar for the rear. This is a bar that goes diagonally from the axle to the body in order to keep the axle centered under the car. In lowering the car, it slightly altered the suspension geometry so that the left side of the car now sits about 3/4" higher in the rear. The adjustable Panhard bar will return the axle to the center of the car, and level the back end out. I haven't felt anything distinctly different, but I'm sure there's some "push" from one side.
You can view some pictures after the modifications, and compare them to a "before" picture. The easiest place to notice the difference is in the gap between the wheel well and the tire.