Dan can you please explain this to me...
How come adjusting the shock length doesn't affect the travel?? Example, would you have 4 inch travel at min. and max shock body length?
More picture on how adjusting the length?
great question
im sure others are confused about this as well
to understand this, you have to understand how different coilover systems achieve lowering
most kits ( bilstein, koni, h&r, kw, fk, patec....etc) achieve drop by lowering the spring perch
I will show for example how this is done
in the first picture you see the coilover how it comes out of the box
in the second picture you will see the spring perch lowerd about 2"
this is how the "other" kits would achieve drop
so when the car is taken off the lift and put onto the ground, the shock will compress 2" before it becomes in contact with the sping
Also by doing this you are reducing the life of the shock as it has to work harder to dampen the same amount of force thru a shorter distance
reason why lowering this way is bad? well the shock has about 3.5" of overall shock travel
this will compress a little under the weight of the car, so now you have about 3" of shock travel to work with, now if you lower the spring perch by 2", you now only have 1" of shock travel that you are acutally using, it is VERY difficult for any shock to properly dampen a car with only 1" of shock travel. The longer the shock travel, the longer the duration the shock has to properly dampen a compression cycle.
In this next example you will see how the cross coilovers are superior when it comes to lowering the vehicle without compromising performance of the shock. In the third picture you will see the coilovers taken apart to show how the length of the shock body can be lengthed to maximum height. In the fourth picture you will see how then can be shortened to minimum ride height. In both settings, shock travel is unaffected. So you have the full 3.5" of shock travel available ( minus droop from the weight of the vechicle).
In the fifth picture you can see the shock assembled with minimum and maximum ride height settings side by side. Again with the same amount of shock travel in both settings. Also by having independent adjustments of body length and spring perch position we can preload the spring. Doing so can make the spring more responsive.