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

[Grant Lenahan]

No difference. The reason its stiffer at some settings is that the 
spring was originally unloaded.  This is all very misleading.

Grant
On Jan 8, 2007, at 5:49 PM, Brandon Rogers wrote:

> Whats the difference bewtween how the grooves work and coilovers - 
> don't
> coilovers just use threads to alter the perch location only?
>
> If it is that stiff at lowest settings - I'd be curious what its like
> when you raise the car - would adding preload, thus raising car, change
> your spring rate?  Actually as a think about it - the I guess the 
> spring
> rate would not change if they are linear rate springs, but _could_ if
> they are progressive depending on where in the stroke it sits....?
>
> Brandon
>
> -----Original Message-----
> From: a4-bounces at audifans.com [mailto:a4-bounces at audifans.com] On 
> Behalf
> Of thejimrose
> Sent: Monday, January 08, 2007 3:30 PM
> To: quattro at audifans.com; a4 at audifans.com
> Subject: [A4] suspension theory thoughts, questions, etc - grooved
> shocks
>
>
> 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!
> jim
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