[s-cars] Re: Eibach Springs & Bilstein Sport Shocks

[Charlie Smith]

Earlier, Voits wrote:
>
> Thanks Charlie:
> I've got the German kit just as you suspected: Kit 1529-140 BUT containing
> p/n's 1527.001 F 1517.002 rear.  This is the same as Djdawson2 reported he
> had on 20 February, at which time he also said, "I was told that these
> numbers never match the kit number".  Not necessarily so, it appears.

Right, the "Kit Number" on the outside of the box is not the same as
the individual part numbers that are on the springs.


> Aside from helping to identify the parts I own, I dont quite know what to
> make of the dimensional differences between the parts (in their unloaded
> state).
>
> a) Based on Bob's data below, the (German) kit I own might have my car
> sitting higher than the US kit -- except for the thinner diameter and
> correspondingly lower spring rate that would cause it to deflect more than
> the US spring thus offsetting some of this difference.  (What I'm seeking is
> ~1.25" lower with more firmness, but not too firm. Also want the car to sit
> level or w/ barely perceptible rake) What would you expect if I install?

You do not need a spacer.  A spacer makes the spring perch sit 1 cm higher,
toward the top of the shock.  With the Euro kit springs you will need to
machine another snap ring groove in the shock - 1 cm LOWER on the shock
body - toward the bottom.


> b) What about the spring perch?  Needed or not?

It is needed.  When you look at your new Bilstein Sport shocks, you will see
a ring around the middle of the rear shocks.  It is just a little bump that
protrudes out from the smooth side of the shock body.  This ring is really
a thin removable snap ring.  If you carefully pry the end of this snap ring
out a bit, you will see that there is a very tiny, shallow groove machined
in the body of the rear shock.

The spring perch slides down on the shock from the top.  It looks like a
coffee cup saucer with a shock size hole in the middle.  When this is slid
down on the shock body, this is what the bottom of the suspension spring
sits against.  The snap ring determines how far down the spring perch fits.

For the longer Euro kit Eibach springs, this spring perch needs to be about
1 cm lower on the shock body.  So take the shocks to a machine shop, and get
them to cut a second groove in each shock that is 1 cm closer to the bottom
of the shock.  I'd paint the grooves with some sort of primer so that you
don't get rust in future years.

Doing this will put your car's ride heigth about where you want it.  Take
a look at the URL of a picture of my S6 in the last email to see where
you will be.

    - Charlie



> Earlier, Voits wrote:
> >
> > I checked availability of Eibach widely (bracing myself for a search) a
> > couple months back and 4 of 8 jobbers (or thereabouts) could get them,
> > referring to factory availability. I purchased from shox.com along with
> > 'spring perch' spacers because of price and off-shelf availability.  The
> > sales person didn't know anything about the perches until I asked him and
> he
> > checked with someone else, at which point he said they're required.
> >
> > spring 1529.140
> > perch 1529F.PERCH
> >
> > The part numbers screened on each spring matched those posted by a lister
> a
> > month ago.  I have not yet installed -- need to buy shocks.  Until I read
> > Charlie's post I was completely confident that I had the right stuff.  My
> > default path is to install with the rear spring perch spacer being careful
> > to measure my before & after ride height.
>
> You can NOT go by the 1529.140 "Kit Number" on the box.  Read on a bit.
>
> It sounds like you have the later "correct spec" springs.  The difference is
> most apparent in the rear, but the front's are different too.  Both spec's
> of Eibach springs will lower you car a lot.  Here's a side view of the S6
> with the first spec springs on it:
>     http://elektro.cmhnet.org/~audi/s6q95/img01.html
>
> Here's some notes from Bob Rossato in November 2000 about the differences.
> The p/n's Bob is noting are those marked on the springs.  The part number
> for the entire kit (on the box) was marked the same on both types.  That
> number was 1529.140 because in Europe that number was for a different spec
> kit than the same number as used in North America.  An other archived email
> said that the Euro kit was for a 2wd Avant Automatic, and that Eibach said
> that they would be too soft for the heavier Quattro S-cars.  My personal
> opinion is that the Euro kit is still much better than stock if that's all
> you can find.
>
>      ---------------------
> Bob's notes:
>
> For those of you that have already installed the Eibach Germany 1529.140 kit
> (p/n 1527.001 F, 1517.002 R) that we originally received and may be
> contemplating whether or not you should change them for the Eibach USA
> 1529.140 kit (p/n 1529.001 F, 1529.002 R), here are some of the major
> differences.
>
> The rear spring (p/n 1529.002) from the USA kit is 45mm (1.75") shorter than
> the 1517.002 rear spring.  The wire diameter is the same.  Overall diameter
> is the same.  The coil spacing is approx. the same (0.1" difference).  The
> number of active coils is the same, but the number of inactive coils on the
> USA 1529.140 is 3.5 vs. 5.25 for the German kit, resulting in the overall
> shorter spring.  Also there is no rubber tubing on the inactive coils in the
> USA kit like there is in the longer springs from the German kit.
>
> The front spring (p/n 1529.001) in the USA kit is approx.13mm (0.5") shorter
> and has a slightly thicker wire diameter (16.6mm vs. 16mm) but is otherwise
> the same as the 1527.001 spring.
>
>      ---------------------
>
> Another thing worth mentioning, on Bilstein Sport shocks.  The regular
> Bilstein Sport shocks now come with one snap ring groove for the snap
> ring that holds the spring seat.  These same shocks used to be provided
> with several snap ring grooves so you could set your own ride heigth.
>
> If you find the right supplier, these shocks can still be ordered with
> several snap ring grooves.  The body of the shocks is thick enough that
> you can machine in new grooves yourself.  This is what I did on mine to
> use the original European 1529.140 kit with the 1517.002 rear springs.
>
>
> The other important thing to note for installation of either spec of these
> Eibach springs, is that they will lower the car enough that you won't be
> able to correctly adjust the front camber.  After some thousands of miles
> of hard cornering, you will wear off the inside 2" of your front tires.
> You don't need to ask me how I can be so certain about this  :-)
>
> There is a cure for that.  It requires making a modification to your top
> camber plate - the one that holds the bushing that the top of the shock
> bolts into.  Igor Kessel has written a number of good articles on suspension
> allignment, including making a .pdf file that shows the exact modifications
> that need to be done to the top camber plate.  Igor's writeups and a link to
> download the camber plate .pdf are here:
>
>     http://www.elektro.com/~audi/alignment/
>
> Hope this helps ...
>
>     - Charlie
>
>
>   Charlie Smith   charlie at elektro.cmhnet.org  614-471-1418
>   http://www.elektro.com/~charlie      Columbus Ohio   USA
>   http://www.elektro.com/~audi     photos & technical info
>
>   95 S6 Quattro  -  24 PSI, RS2 6 speed, and other features
>   97 Dodge Ram   -  35 PSI, 4x4 w/Cummins turbo diesel