Coil Spring Cutting

I had the car all together with tires wheels and motor so I knew where it sat....granted I lost about 50lbs by going to an aluminum intake but I had about a 2½ gap from the top of the tire to the bottom of the fender....

 

My avatar is also another pic of when it was all together

 

Not in my experience ... I cut one full coil and it did not drop it four inches as your formula would imply. It ended up being about 1.5".

It will vary with the springs used and how the car is equipped. V8 springs will be stiffer, cutting 6 cylinder springs will gain more drop with the same cut.

A pretty good way to estimate how much drop a cut spring will result in is to measure the spring at its loaded height (fully dressed vehicle!) , then measure it at full extension, unloaded. Divide the loaded height by the unloaded height. That number is a ratio that you can now apply to how much you want to cut off.

You can apply this both ways ... the proposed cut x the ratio will approximate the resulting drop. A targetted drop divided by the ratio will tell you how much height to cut from an unloaded spring.

Mind that this will get you in the ballpark, and the results still can vary a bit. It also relies on constant rate springs (will not work with progressive rate coils).

I would not attempt this at your stage of the game ... I would wait until you have everything back in place and the car at full weight. Asking for trouble otherwise....