General Suspension help.

[Muzz]

*READ SLOWLY AND CAREFULLY*

you would need to preload the coilover harder than the weight of the car for it to work?

thats a very interesting thought.

say each corner of the car weighd 300kg, and the spring were preloaded so they pushed up with a 300kg force aswell, placing the car on the ground would not compress the coilovers at all! so therefore if the car got air or watever, the coilover would not extend any further that if the car was at rest on the ground.

the same situation without preload springs the car would sag down compressing the coils with its weight.


in the 1st case, the car has no negative suspension travel (where the coilover can extend longer than its legnth when the car is at rest), and in the second case it does.
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With all this said... your shock would not bottom out.. it would top out and go THUG as you air bourne abit and your coilover would proabably pop a socket

exactly.
and increasing the preload ABOVE the weight of the car would be dangerous, as when the coilover is compressed and released, it would extend and hit the top of its stroke with even more momentum, which would lead to sudden decrease of weight on the wheels, as the coilover hit its top.

i think all cars must have negative susp. travel (watch them get jacked up off the ground), it sounds dangerous otherwise.
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adding preload from having none at all, will push the car upwards, and thinking about it now, adding preload wont change the force needed to compress the coilovers a given amount, compared to having no preload.

eg. the corner of a car pushes down with 300kg of force on a coilover which has say 200kg of preload pushing up.The cars weight will overcome the preload anyway, leaving the spring to work as normal.

Think about all this carfully before reading on.

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What changes by adding preload is the ride height, but also the amount of negative suspension travel the coilover can experiance.

eg. as before 300kg of weight on a coilover with 300kg of preload, will not compress from the weight of the car alone. therefore at rest the shock has no negative suspension travel.

and with no preload, the car has the ability to extend the shocks, because there already compressed, allowing negative suspension travel.
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Its clear to me now, that coilovers that allow seperate height and preload adjustment allow you to keep your optimum ride height, while adjusting the amount of negative suspensin travel.

ADJUSTING THE AMOUNT OF NEGATIVE SUSPENSION TRAVEL ON A CAR HAS A VERY INTERESTING EFFECT DURING CORNERING!

im at uni now so wait till i get home and can explain with pics, imposible for me to otherwise, but reducing the amount of negative suspension travel available actually causes the center of gravity to be pulled lower to the ground during cornering, i researched this for a yr 12 report in 2004