[A4] suspension theory thoughts, questions, etc - grooved shocks

thejimrose thejimrose at gmail.com
Wed Jan 10 16:07:24 EST 2007


wow guys thanks for all the responses. i've read and reread several times to
pick out next steps from here.. still crunching on it all.

so a few clarifying points - yes i understand that my grooved struts have no
real preload feature [unlike the lovely shock that resides on the back of my
triumph... why aren't car shocks made so nicely? =]. and i also understand
/agree that changing the lower spring perch height in relationship to the
upper perch [which is fixed, mounted the car, and only as far away as the
maximum shock piston stroke allows it to be.

i guess what i was wondering is if + how, in theory and in practise,
changing the maximum overall spring distance effetcs ride, performance, etc.
it seems to be a bit of a hack, or an ancilliary effect, that if you put the
spring under more compression [hence my thought that it was simply
preloaded] it will have a raising effect on the car, since it's pushing
harder.

what i forgot about is sag [in motorcycle speak] since i spent to much time
looking at it unloaded. the car can not sit higher than the shock will
physically allow. however since the spring is under more compression with
the perches set higher, the car will sag less when it is under it's own
weight. thus raising the car. i'm probably using all the wrong terms, im as
far from an engineer as you can get, but i *think* i am getting how it all
works.

in looking at 'real' "coilover" designs [i too have always thought it funny
that they're called coilovers when pretty much every suspension i've come
across is a shock inside a spring] they do all use the same principal - an
adjustable lower perch. with the exception of the stasis motorsport
coilovers, these look like they have an adjustable upper perch as well. and
they outta at 4grand.

so it seems that it comes down to proper spring spec, legnth etc. i need to
do some research + checking. i will also take taka's advice and look into
having the shocks valved to match the springs. the car isn't too bad, but i
do get the feeling that it could be a little more controlled.

ill reprot back when i have some more info. thanks again all for the help
and input!

jim


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