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#9: 07-24-2012, 08:12 AM
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Originally Posted by scoobyscoodle View Post
If the spring is a progressive rate, then yes, putting preload on it would essentially increase the rate since you are compressing it to the point that the rate increases. Most coilover springs are linear, so the rate is the same through the entire travel range. A 400lb linear spring has a 400lb/in rate uncompressed, compressed 1", or compressed 3", it does not matter; the spring will always take another 400lb of force to compress an additional inch.

Preload is just stored energy in the spring. If the stored energy in the spring from preloading added up to the weight of the vehicle or more, the springs would not compress at all when dropped on the ground.

RCE/KW's adjust height by adjusting preload only. They do not have a separate height adjustment like BC/ISC etc. etc.
This doesn't quite make sense to me. If we're talking about a linear rate spring and you are saying that another 400 lbs will compress the spring the an additional inch (until full spring compression anyway), then how does preload affect ride height?

Do you see what I'm saying here? The sprung weight of the car does not change in this scenario. If you are saying that the amount of preload already on the (linear rate) spring does not affect the amount of spring compression (still always 1" / 400 lbs in our example), then the car, should fall the same distance when set back down on the suspension, right?

I'm confused. Please clarify if able. I swear I'm not trolling on this issue, I'm just trying to reconcile my understanding. Thanks!