[s-cars] Recap of Eibach and Bilstein Info

[Charlie Smith]

This is an attempt to summmarize information about Eibach Pro springs
and Bilstein Sport shocks for our UrS4/S6 cars.

First, you can NOT go by the Eibach 1529.140 "Kit Number" on the box.  You
have to look at the actual spring part numbers that are on the springs.

There are three combinations of springs.  The difference is most apparent
in the rear, but the front's are different too.  All three spec's of Eibach
springs will lower your 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

There were three combination of spring part numbers in various Eibach
spring kits that were marked 1529.40 on the outside of the box.  The first
section of this discussion covers the just the first two kit combinations.
The third section way down at the bottom of this discussion covers the most
recent (third) combination of springs.  The Eibach spring part numbers
which are marked on the springs for each of the three combinations are
 as follows:

   1529.40 Kit combination one:    p/n 1527.001 F, 1517.002 R
   1529.40 Kit combination two:    p/n 1529.001 F, 1529.002 R
   1529.40 Kit combination three:  p/n 1527.001 F, 1516.002 R

Ok, the discussion on combinations one (Euro kit) and two (USA Kit) follows
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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.

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Now, regarding the third combination of spring part numbers that has
recently turned up:

First Dave Dawson wrote on May 13, 2003 (slightly paraphrased):

A friend recently bought the infamous Eibach 1529.140 kit...
Upon opening the box, there appears to be yet another variable in the Eibach
equation.  My set was labeled 1527.001 (fronts) and 1517.002 (rears), as were
several other lister's sets that I've talked to about Eibachs.  His rears are
labeled 1516.002.  They are also missing the rubber sleeve that is installed
on the "inactive" coils of the spring.

To figure out what's going on, I called Eibach... and after much delay,
got on the phone with a tech person.  Here's what he said:

Anyone who got a set of springs labeled 1517.002 for the rears, got the
wrong rear spring.  The new number (received from shox.com this week)
is 1516.002 for the rear spring.  According to the Eibach person EVERYTHING
about these two different rear springs is identical (both spring rates,
coil diameter, wire diameter) except the 1516.002 is 30mm shorter unloaded
and unsleeved.  The free length of the 1517.002 was 335mm, while the
"correct" 1516.002 is 305mm.  This explains the 1970's "jacked up" look
that myself and others have noticed.

[ Note from Charlie:  What Dave heard below from this Eibach person    ]
[ is probably incorrect, because this Eibach person doesn't know about ]
[ the previous GP confusion of combinations 1 & 2 discussed above.     ]

The Eibach "technical" person claims that nothing (in terms of spring
specs) ever changed for this spring set, US or German.  The only
difference was where they were wound, some here, some in Germany.
The confusion started in the US when they offered Pro Kit Dampers,
on which the rear perch problem existed.  For this, they offered the
spacer.  Otherwise, he claims that they are currently offering the
ONLY spring kit they have EVER offered in any country.  Part numbers
have changed, but the specs have remained identical, according to the
specs he was reading to me.

[ again from Charlie, the Eibach guy appears to be wrong on the above.  ]

So on that note... If you bought a 1529.140 Pro Kit from anyone, and it has
1517.002 rear springs, he said that Eibach would replace them with the
correct springs.  He said those folks should call Eibach at 909.256.8300 and
talk to Scott Curry at extension 130.

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After Dave's email just above, Bob Rossato then wrote the following,
which goes along with my comments above about this Eibach "technical"
person not having the full facts.

Bob Rossato's email:

I was part of the GP for the 1529.140 UrS4/6 kit ~3 years ago.  Eibach had
officially discontinued the 1529.140 kit a year or so earlier but some folks
at Marcor in Canada and another place in CO whose name escapes me, convinced
Eibach to make "one last batch".  The first kit we got had the 1527.001
fronts and 1517.002 rears and folks on the list that had purchased the
original 1529.140 kit pointed out that the spring numbers were different.
The original kits had 1529.001 fronts and 1529.002 rears.  After much
perseverance by Peter Anderson who coordinated the GP, Eibach admitted we
got the wrong springs and made a new batch for us.  When the new set arrived
I had the opportunity to compare the two sets side by side and take
measurements (both brand new out of the box).  There definitely was a
difference between the two.  The 1529.001 fronts appeared to be stiffer than
the 1527s based on larger wire diameter and shorter free length.  The
1529.002 rears had the same wire diameter and number of active coils as the
1517.002 springs, but had ~2 less inactive coils than the 1517.002s making
them 45mm shorter, which I guess makes them 10mm shorter than the specs you
listed for the latest rear spring (1516.002).  Hey there's our 10mm spacer
;-)

If Eibach is now claiming that the specs between the old 1529.001/.002 and
today's 1527.001 & 1516.002 (1517.002?) are the same, then one way or
another they don't have very good records.

  [  end of Bob's comments.  ]

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And for a semi-complete summary email, I'll include what I've said earlier
about the Bilstein Sport shocks, along with some notes from Ray Tomlinson
on Bilstein revalving:

     ---------------------
First, the part numbers for Bilstein Sport shocks for our UrS4/S6 cars:
    P36-0369 front
    B46-2066 rear

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 four 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.

Also, Bob Rossato has posted this note:
     ---------------------
I went through this last year when I got a set of Bilstein Sports for my
Corrado.  I called Bilstein here in CT and asked about the sports only
having one groove whereas the application guide specifies that they're
adjustable for the rears.  Apparently this is the way they're coming through
now but he stated he could get additional grooves machined on if I wished.
I expected there would be a charge but was pleasantly surprised when he
offered to do it free of charge since the application guide specifies an
adjustable perch.

The service is actually done at the San Diego facility.  Since I hadn't
installed mine yet I asked him to just order another set from San Diego with
the additional grooves machined in and when they came in I drove down and
swapped them.  Took about 2-3 weeks to come in.  The only problem was that
he asked them to machine in 4 additional grooves but they ended doing only
2 additional grooves.  Oh well, better than nothing.
     ---------------------



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/


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Here's Ray Tomlinson's notes on Bilstein valving:

I've spent a little too much time on the phone with Bilstein lately.
After speaking with Shayne in tech support/sales, I came across some
interesting valving numbers.

For $55 additional charge per strut, Bilstein will completely rebuilt any
monotube strut with custom valving.

Here are the stock rebound/compression settings for my struts:

P36-0369 (front):  119 rebound /107 compression
B46-2066 (rear):   125 rebound / 80 compression

Shayne indicated that increasing rebound by 25% in the front, but not as
much in the rear, will help control some of the nose-dive we experience in
the UrS-cars.

By comparison, the neu-S4 2.7t's valvings are as follows:

front:  273 rebound / 90 compression
rear:   353 rebound / 119 compression
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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   -  40 PSI, 4x4 w/Cummins turbo diesel