Droop, and preload

[THR]

how is droop and preload measured?

how is say, 5mm droop measured?
and why 5mm?

how is zero droop measured?

car in the air? on the ground, preload on or off?

why 2 turns preload on the springs? y not 5?

how do the pros do it?

yours thoughts please!!

[THR]

no body know?

[enzo]

Looks like no one else wants to , so I'll volunteer. I'll just start by defining terms.

Zero Droop: Shock extended length is set so short that there is no droop travel permitted from ride height length. Generally it is set by adjustable stops that contact the end of the shock eye.

Droop Limiting: Shock length is set so that there is only a small amount of droop available from ride height. Can be set either by adjustable stops, or by putting internal spacers in the shock.

Preload: There are two types of preload.
1) When droop limiting, the adjustable perch on the shock body is set so that the spring is still compressed a bit when the shock is fully extended.

2) When zero drooping, the spring is compressed more than the amount necessary to support the car at ride height.

The amount of preload, the amount of droop limiting, etc, is all determined by what you hope to accomplish. The numbers can vary widely from car to car & track to track.

[THR]

So would anyone disagree with this?
after some research this is what i have come to:


with some lard arse in the car (hobbit). and tires set to normal running pressures.

Front:
ie no droop.

start to jack car up, watch the shock, if it extends AT ALL before the wheels are off the ground, it has droop. this is bad.
wind the shock up more..
try again..
eventually the shock wont move at all, and the wieght of the car will be balanced by the preload that you have now put upon the spring.
then wind it back a bit to make sure that there is not to much preload. the shock should just about move.
preload is just a measurement of droop.
so write it down! if the softer springs are used less preload is needed. and vice versa.


Rear:
aim for 10mm droop i suggest.
wind both springs up so they have 1 turn preload. measure the height off the floor the car floor is. jack the car until the wheels are JUST off the ground, both will lift off at the same time i guess, measure the height again, this is the amount of droop. for less droop wind the spring up more.

[Barry Pomfret]

If you wish to lessen the amount of droop this can be done by winding up the spring platforms but it will also raise the ride height of the car which usually causes the the car to exhibit more of an oversteer characteristic. To compensate for the increased ride height the push rods will need to be shortened to bring the car back to its recommended ride height setting. Rear droop figure of 10mm is in the ball park for most modern single seaters, our current Zetec Formula Ford runs approx.14mm for most circuits.