fred g., I dont have any experience cutting coil springs but I have been looking into cutting mine also, my 03 sits very high in the back and all of the spring sets I have seen lower the car in the same stance, in the end I may go with coil-over but in the mean time I thinking about cutting .5 of one coil from each rear side and just see what happens I am told you always cut from the bottom, If it does not work I will drive down to tommie vaughn racing and buy some
I've trimmed specific rate springs before with no problem. But I've never cut a progressive. I recently went to the Steeda Sports and I'll be damned, I would have bet my last bottom dollar that the car was perfectly level for the first few days, but then all of a sudden, I thought I noticed a little more "air" over the right rear tire. The left rear measured the same as the day it was installed at 27 1/4", but now the right rear was up at 27 3/4". (Which I might add was about the height with the stock rear springs minus the insulators!). The rear height was at 28 1/4" with the insulators in place. The guys at Steeda are working with me on this, but.....this was my first experience with progressive rate springs and these springs have to a billion coils on them. So...while the factory spings, using a simple spring compressor, basically fell out of the car, there was no way these progressives were going to compress enought to install without major BS (considering this was a driveway project). As it turns out, I had Joe at Mustang Magic do the install, and at that, he broke is chops, having to lower the back of the IRS cradle to get them in. (and just two weeks before, we had just done the MM bushings!).
Anyway, point is, to experiment with these is no easy deal. The springs provided a 1" drop which is all I wanted, but now I have to do something about leveling the car. The car measured identical at 28 1/4" left and right with the stockers, so I'm taking the typical factory left to right tolerence out of the equation. The Steeda rep suggested swapping the springs from side to side, which I don't want to do, since I know the car measured the same prior to the swap. Were gonna take a look and see if maybe the spring is out of position in lower control arm, but if not, I'm not sure what to do, short of cutting some of the spring to try to level it out. Mustang Magic is an authorized Steeda Dealer and basically Steeda is saying they'll let Joe make the call to do whatever is necessary to rectify the problem.
Also as far trimming from the bottom, the coils open up at the bottom and are wound very tightly from midway up the spring to the top,which was the problem in trying to compress them. I would think that I'd want to trim maybe one coil off the top, no?