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      01-10-2010, 10:34 AM   #13
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Drives: E30 M3; Expedition
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Originally Posted by JAJ View Post
So, how does this play out in suspension mods? Well, if you just put “lowering springs” in place, the suspension has to sit lower than stock (duh) so the spring has to be SOFTER than the stock spring. You've also used up some of the two inches available travel. The four inch rise of the suspension has to become five inches to get a lowering of one inch, and the remaining travel is reduced to one inch. One inch of travel is "not much" in anyone's language.
Thanks for the write-up JAJ.

Not sure about your conclusion above though regarding the stiffness of the "lowering" springs. It is possible to use shorter but stiffer springs to achieve the drop (shorter natural length but higher k). That could offset some of the drawbacks of using up the "avaliable" travel built into the stock suspension since the stiffer spring would compress less under the same loading conditions. In that scenario, the main issue is changing the spring stiffness without modifying the damping ratio. In a properly tuned system, they need to be modified in conjunction if the modifications to the stock system are significant. Of course, one can debate what "significant" means.