RE: Springs

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

> By putting the close coils at the top of the strut it completely defeats
> the purpose of having progressive rate springs to begin with.  Let's all
> think here for a sec.  As the car compresses deeper into the corner the
> upside-sown spring will be getting progressively LESS stiff, while at the
> same time normal driving will be like driving with straight rods as
> shocks.
>  If this is incorrect please correct me with meaningful reasons.
> 
... I'm sorry Dave ... (he says in his HAL 9000 voice :) but you are
incorrect ...

A spring can't tell if it is rightside up or upside down, it will behave the
same way in either case ... compressing based on the force applied from end
to end.  What others have suggested is precisely what should be done with
progressive springs ... the closer pitch means that these coils will touch
first and become "dead" coils ... no longer acting as springs ... and
thereby increasing the effective spring rate.  By placing the tighter wound
coils at the top the dead coils become part of the "sprung" weight of the
car.  If the dead coils are at the bottom of the spring they become
"unsprung" weight, which is less preferable ...

HTH!
Steve Buchholz
San Jose, CA (USA)