[CL9] Euro Mods

[aaronng]

Front Spring rate 280 lb./in. times converstion factor of 0.0179 gives you 5kg/mm
Rear Spring rate 175 lb./in. times converstion factor of 0.0179 gives you 3.13kg/mm

So your car's pretty much 2x as firm as stock

Dug through my old posts from years ago and found the same numbers as your calculated ones.

It is pretty stiff for stock. In fact, the rear of the stock spring is stiffer than Tein S-tech spring.