These are actually sport springs, designed to lower the car about an inch. They have markings on each coil designating which way is up. During assembly, I actually tried to put them in upside down just to see what it looked like, and it was pretty obvious it wouldn't work. Also note that these springs are the same length as stock when unsprung, so they must just have a different spring constant.

I see where you're going. Perhaps I didn't tighten the star nut down enough while the struts were out of the car? At the time I remember thinking that it wasn't clear how far down to screw them, so I just tightened them down to where the spring was compressed with the compressors still installed, then I removed the compressors, allowing the spring to tighten up into the upper mount. My only guide for how far down to screw the star nut onto the shock piston was making sure I allowed enough threads on top for the big washer and final nut.

My logic at the time was that it didn't matter how far down I tightened that star nut, because it would only dictate the compression of the spring (and its force against the bottom mount), in an unsprung state. The real forces that would prohibit the spring from rotating in the bottom would be when the car was sitting on its own, compressing the spring even further to the resting state.

So to that end, I'm still confused as to how the star nuts tightness has any bearing on the compressive forces on the spring when the car is sitting on its own wheels.