You've got the right idea... if the center of the spring seat in the lower a-arm is 1/2 distance between the lower a-arm inner pivot point and the center of the tire contact patch, then 1 inch cut from the *loaded height* of the spring will result in the car sitting approximately 2" lower. Incidentally, I don't know that the spring seat *is* 1/2 distance to the contact patch, you'd have to measure to confirm that fact. Also notice I've tried to emphasize the term "loaded height"... we're not making the *free height* of the spring 1 inch shorter, we're making the *loaded height* 1 inch shorter.

WRT rate change, according to the manual, stock 140 front springs are nominally 310 lbs/in. If you start with a stock 164 front spring, you're up to about 360 lbs/in, again per the shop manual. If you eliminate one free coil, the spring rate will go up about 14%, to around 410 lbs/in, assuming the stock spring has about 7 free coils. (The 164 manual is a little fuzzy here, but I *think* it says they have 6.83 free coils.)

Keep in mind, the term "free coils" is important when calculating rate changes. If you simply lop off the top or bottom coil and stick the spring in the car, you can throw all this math out the window because those coils aren't "free" to start with. As installed and loaded, the bottom and top half-coil (or so) are typically "coil bound" due to the way the spring is wound. This flattened seating area of the stock spring needs to be duplicated (reshaped) when you cut it, or like I said... this math is all out the window.

Bottom line, you'd be increasing the front spring rate about 30% in the example above... you're going to have to do something at the rear of the car to compensate, or you're going to end up with a LOT of understeer.
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Gary Learned - '71 142E ITB / '73 1800ES / '02 S60 T5