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

thejimrose thejimrose at gmail.com
Mon Jan 8 17:29:36 EST 2007

hey all - i've got a question and some thoughts and btdt i'd like to throw
out for collective rumination, enjoyment, infotainment and maybe
edification. i installed a suspension kit on my a4 from neuspeed [got it
used, cheap] that includes bilstein sport shocks and neuspeed sport springs
[a bit lower and stiffer]. the shock bodies are grooved and include a big C
clip which the lower spring perch sits on, to allow the ride height to be
'adjusted'. it's nothing new, but i'm suspicious of its merit.

what i don't understand is how raising / lowering the lower spring perch on
the shock body will adjust ride height? all it seems to do is preload
[compress] the spring, since all it does is shorten the distance from upper
to lower perch. it doesn't change suspension geometry at all. i do
understand that, as a byproduct of this preload, that the car
could/would/should sit a little higher since the spring is pushing harder
against the body, which is more likely to give than the road.. =)

the question comes because, in installing them it was almost impossible to
get the springs compressed enough to squeeze into the 'highest' ride height
setting - aka the uppermost lower spring perch setting aka the shortest
distance between the perches aka the most preloaded spring. set this way
there is virtually no room between several coils - they touch, so there
isn't much room to suspend if the spring coils are touching at that point
it's a sleeve not a spring =]. the NS springs have far more windings than
the stock sport springs do.

as a review, i'm not thrilled with the setup so far. it does handle like a
gokart [for good and bad], its a load of fun but very bouncy and the car
wants to launch itself when the suspension unloads over bumps. there is NO
dive or squat or sway. it's a crapload of fun in the turns but is unsettled
easily. when i installed it all i planned to set the perches at full high,
but i ended up installing them full low, partially because i figured it
better to have the least preloaded spring, which i thought would ride better
vs a higher riding, but more preloaded spring. i was also forced to install
them full low because the crap compressor i have wouldn't allow me to
physically compress the springs enough to squeeze them between the perches
[at the highest setting]. ideally i would want slightly higher ride height,
but i'm afraid of preloading the spring more and losing what little ride
compliance there is. [i have a feeling that i just asked the suspension holy
grail question and the only answer is $$$$$$$$$ =]

so i guess my questions are; is my understanding of the adjustability and
function accurate? i'd like to validate my suspicions before i make more
changes. what i'm thinking is to install my stock sport springs on the
bilsteins but i'm worried it would go the other way [overdamped - soft but
harsh]. ive heard this setup works well on non-grooved shocks.

did any of that make sense? =)
thanks all!

More information about the A4 mailing list