Spring Pre-Load: Help me understand the physics.

GSS138

Spring preload serves two purposes that I know of:

1. It keeps the spring in place so that it does not shake free/rattle/lose contact with the perch under extension(very bad).
2. It adds a little bit of "softness" to the ride. OEM springs are always pre loaded to this effect.


Preloading a 400l b spring 1/4 inch effectively gives you 100 lbs of preload. This will "eat up" the first 100 lbs of weight applied to the spring and give it a slight progressive effect.

Since you have effectively used and compressed 100 lbs of weight, you should subtract that weight from your unsprung corner weight when calculating ride heights. i.e.


400 lb corner weight(unsprung) on 400 lb spring= spring will compress 1"

400 lb corner weight(unsprung) on 400 lb spring preloaded 1/4" = spring will only compress 3/4" more.

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Current Mods: Vorpal Weapon +5.