[s-cars] RE: 1996 s6
Frank Amoroso
FAmoroso at svbank.com
Thu May 2 11:08:44 EDT 2002
I suppose the stock middle resonator really baffled the heck out the
exhaust.
FA) You're not kidding. Heavy sucker too! Depending on where you stand on
the issue, you may consider a set of gutted cats.
The performance of my car has escalated very nicely. The stage 1 Hoppen
ECU tuning was a great investment, despite some detonating which still
occurs in 4th and 5th gears under WOT, which I hope will be fixed when I
switch my sparkplugs to the ones you recommended.
FA) How many miles on the car? You might also consider a new set of plug
boots / wires at the same time.
My next plan is to upgrade to 17" wheels with the 245-45-17 tires you
also recommended.
FA) Did I recommend that size? If so, it was a typo. What I should have
suggested was either 245/40-17 (preferred) or, secondarily, 235/45-17.
BUT, the more I drive this car, the more I realize
that the chassis and stock suspension cannot keep up with the increased
power. I have way too much nose dive etc. under aggressive driving. It
makes me think that your advice about the Bilstein shocks and Eibach
springs is a better investment than new wheels! Suspension is something
I underestimated about this car, and the newfound power makes the
chassis feel incompetent.
Your notes, however, about the suspension mods have me concerned about
the intricacies of having someone reputable install these new parts and
actually get them dialed in correctly. Where do I buy the new camber
plates and new strut bearings, in addition to the springs and shock?
FA) You don't need to buy camber plates, as much as you have to have your
existing ones removed, drilled, and re-installed according to Igor Kessel's
write-up / procedure of ~ one year ago.
Read this...
http://groups.yahoo.com/group/s-car-list/files/Documents/Suspension%20Revist
ed.doc
I have included a copy at the bottom of this message.
Strut bearings can be purchased from the dealer or a handful of other parts
vendors.
Springs and shocks I would get from www.shox.com. Although I did hear that
Tom @ ECS tuning just got in a shipment of Eibach Pro-Kit springs (in case
shox.com can't get them for you.).
http://www.euro-car-service.com/s4s6modpage.htm
You do not need the ECS camber plates. They are expensive and heavy, and
stock drilled ones work just as well (considering you already own 'em, I'd
say they work better).
How much is the whole package?
FA) That's a tough call. I can't say for sure as I did mine in stages. Wish
I would have done it all in one shot. I have cc'd the S list on this
message, so others will chime in, I am sure.
Are there any special things to consider prior to the install?
FA) Depending on age / mileage, you may want to consider renewing rubber
bushings in the suspension.
Will me ride be compromised significantly?
FA) Not really. The Eibach Pro-kit + Bilstein Sport combo works quite nicely
on the street. If you are concerned, and want to help preserve the comfort,
you can still go with an 8" wide 17" diameter wheel (as light a wheel as you
can afford, please!), and run a softer sidewall tire in the 235/45 size as
opposed to the 245/40. Nice part about this is that you can always go with
the other size next time, should you so choose.
Frank-
Suspension Revisited: UrS4/S6 Suspension Tuning In Detail
Contributed by: Igor Kessel (igor at s-cars.org)
Folks,
Over the last week I have finally sorted out my suspension and weeded out
all of the bugs. I am planning on doing a series of posts that might be of
interest to anyone with the similar to mine set-up, or planning to do any
other lowering set-up for that matter. Here's the first post.
1. As you all know, if you lower an UrS you'll screw up the Camber. In case
of my Eibach/Bilstein the actual Camber maxed out at -1.4oe symmetrically
left to right. I have noticed that the inner edges of my 245/40/17 SP8000 on
the 8" wide A!Avantgardes were wearing out. Mind you, this was not happening
with the 225/50/16 SP8000 on the 7.5" Momo Arrows off my wife's A4 installed
on my S6. Hmmm... Anyway, I needed to measure my Camber before and after
doing the planned corrections. I needed a Camber gauge. Well, as always, I
didn't have one so I decided to build my own. I went to Sears and bought a
3 foot long Aluminum angle, 1" x 1" x 1/8" thick. I also bought a
carpenter's steel rule 12" x 12" at 90oe, two little carpenters
"quick-grips" and a digital Smart Level. I cut a 17" long piece out of the
3-foot long Aluminum angle, so that it could be rested on the edges of the
16" Avus rim. I drilled a few holes and tapped a few threads in both parts
and mounted the carpenter's steel rule in the center of the 17" long piece
of the Aluminum angle. After calibrating the Smart Level first, I measured
the horizontal slope of the floor in my garage to account for the systematic
error. It had turned out to be only 0.1oe. I then disassembled the Smart
Level and mounted the central digital part on the ruler, at 90oe to the
Aluminum angle. This device has become a reasonably accurate (1st place
after the decimal point) yet very repeatable "MacGuyver" Camber gauge. It
could be mounted on the side of the wheel rim with the two little
carpenter's "quick-grips".
Part II
2. As you know, Bilstein shox are of the inverted tube design and as such
have a very large DIA moving shaft (~46mm). Therefore they come with their
own top screw-on strut caps with built-in oil seals. This cap replaces the
OEM cap with the hex recess for the OEM Audi tool. The Bilstein cap has two
8mm wide slots instead and comes with a wimpy flat key that fits into those
slots. The key goes in through the side in between the spring loops and has
a 1/2" square hole on the protruding end. This key is utter garbage. I
destroyed two of them on the first attempt. First - mine, then - Stefan's
when we were later doing the identical to mine Eibach/Bilstein install in
his car. Besides, this key is very inconvenient to use because you need to
remove the dust boot first; and you can only do a 1/8 of a turn at a time.
And you can't really use a torque wrench on it too.
Last week I tried to use this key to remove the caps after 1.5 years of
sitting on the struts. No friggin' way. Had to go to Sears and buy a pipe
wrench and whack the hell out of it with a BFH before the cap would yield. I
needed to fabricate a proper tool for screwing the caps back onto the strut
towers afterwards. Fortunately Sears sells a tie rod end removal tool which
looks like a 40cm long black pipe with a 1/2" square on one end and a
funnel-like opening on the other, into which the Bilstein cap fits
PERFECTLY. As if it was made for it. But the real icing on the cake were the
two 5/16" slots cut in the opposite sides of that "funnel". I bought a piece
of 5/16" square key stock, cut it in two with a diamond wheel (man, was the
material hard!) and welded the bits into the slots. The tool fits the cap
like a glove (5/16" = 8mm approx.), can be dropped into the strut tower
through the top and enables the Bilstein shock removal in under a minute. I
do not know the p/n of this particular Sears tool coz it was given to me by
a friend who had bought it a long time ago, but I am sure you will be able
to find it.
3. Another tool that you will need is a regular spring compressor. Any Pep
Boys would lend it to you free of charge. I have fabricated my own a long
time ago. Mine utilizes two conical bearings under the compression nuts so
that the nuts are very easy to turn coz you are not fighting the friction.
4. In order to remove the front springs you NEED to hang both wheels out in
the air as not to fight the torsional resistance of the stabilizer bar. In
my case even this measure was not enough. I was alone in the garage, in a
desperate need of an extra pair of hands and was looking for a way to press
the half axle down to the sub frame while I would be removing the compressed
spring from under the front fender. I came up with a simple one man
solution. I took the OEM Audi screw jack (yeah, the suicidal one with which
your car came from the factory :-), shoved it in-between the half axle and
the upper body longitudinal member and easily lowered the strut until the
half axle hit the sub frame. After which I was able to remove the spring
with ease.
Part III
Modifying the front top mounts.
Folks, first measure the horizontal slope of the floor of your garage with
the Smart Level described in Part I and write it down. Measure both the
front and the rear Camber with the gauge described in Part I and write them
down. I am assuming that you have all the proper tools, including the
special ones described in Part I and Part II.
Put the front of your car on two jack stands. Do not EVER work on a car
supported by a jack alone! Remove both front wheels, both front shocks and
both front springs.
There are two mounting parts in the top of the front strut: a large round
plate with three M10 studs and three M12 studs (hereinafter called PLATE)
and the smaller triangular shock mount with three elongated 12mm slots
(hereinafter called MOUNT). Remove the PLATE from the car.
As I stated before, if you lower an UrS you'll screw up the front Camber
beyond factory adjustment. In case of my Eibach/Bilstein the actual Camber
maxed out at -1.4° symmetrically left to right. Hence the need for
modification of the front top mounts.
If you just grind the slots in the MOUNT a little longer it will not give
you the needed adjustment range coz the MOUNT will be hitting the inner edge
of the PLATE. I used the brilliant idea suggested by Peter Blaser: "There
isn't any camber problem at all. All you have to do is modify *BOTH* top
plates. You take out the black one, which bolts to the frame, knock out all
six studs, and re-drill them so that the black plate sits as far outboard of
the center line as possible. Then tap the studs back in."
I would like to make one important correction. Although you do need to
re-drill and re-press all 6 studs at 180°, you only should offset the outer
10mm studs outward by 4 to 5mm. The inner 12mm studs should remain on the
original bolt circle. If you offset the 12mm studs along with the 10mm ones,
they will negate the gain obtained by moving the 10mm studs outward. See the
illustration Fig.2. I've done it wrong the first time around and only
discovered the error when I mounted the PLATE back into the fender.
Fortunately the round PLATE has four sides to it, so I flipped it 90° and
re-drilled all six studs one more time, this time in the correct fashion.
I have drawn two pictures for your convenience; the link is provided below.
I have saved both drawings in the PDF format because it was the only way to
preserve the original dimensions. When printing make sure to uncheck the
"Fit To Page" option, otherwise the drawings will shrink. For some reason
Acrobat distorts large circles, but fortunately it leaves the crucial
dimensions between the hole's centers intact. Please verify the dimensions
after printing.
Fig. 1 shows the PLATE before re-drilling. I marked several crucial
dimensions so that you could verify that the picture did not get distorted
between my drawing it in SmartDraw and your printing it off the Internet.
Fig. 2 shows the modified PLATE and does not have dimensions on it as to
avoid overloading the drawing with unneeded details.
I suggest the following procedure.
a) Print Fig. 1 and Fig. 2 and physically verify that the dimensions on your
print are correct.
b) On Fig. 2 punch out all BLACK A and B (OEM) holes with the 10mm and 12mm
hollow punches respectively.
c) Stick a few pieces of double sided Scotch onto the PLATE in a few
strategic places.
d) Carefully fish Fig. 2 over the OEM studs through the punched out holes.
e) Remove the remaining backing from the pieces of the double sided Scotch
and stick Fig. 2 onto the PLATE.
f) Center punch the new holes A1 and B1.
g) Drill small pilot holes in positions A1 and B1. I used a 1/16" bit.
Remove the drawing Fig. 2 from the PLATE.
h) Screw some used nuts onto the OEM studs and punch them out of the PLATE
with a BFH.
i) Ream the A1 holes to 11/32" and the B1 holes to 10.5mm, gradually
increasing the DIA of each subsequent bit by small increments. Use grease on
the drill bits. The PLATE is made out of steel approx. 4mm thick so be
patient.
j) Feed an OEM stud through the new hole and press it into the PLATE in a
vise until the knurled neck of the stud is home. I broke my own vise so I
had to use an alternative method. I would grab the head of the stud with a
vise grip to prevent it from spinning and would press it into the new hole
in the PLATE by tightening a nut with a wrench over the stud.
In addition you can expand the slots in the MOUNT by grinding them a little
longer to gain a few more millimeters of adjustment.
Mount the PLATE into the inner fender with three NEW(!) locking nuts and
torque them to spec. Note that now the Dimple is on the INSIDE of the car.
Compress the lowering spring with the spring compressor and install it onto
the strut, observing the proper orientation on the perch.
Compress the new shock absorber a few times and let it release as to remove
the air pockets. Drop the shock absorber into the strut tube. In case of
Bilstein feed the new cap over the shaft and torque it to spec (I think
Bilstein recommends 140 Nm) with the tool described in Part II.
A tip: put some anti-seize on the threads of the Bilstein cap.
Another tip: now is a good time to replace the rubber dust boot (called by
Audi a "SPRING SEAT" 431-412-175-D). Mine was torn in one place. It cost me
only ~$8/ea. with my discount and should be replaced as a preventive measure
coz its replacement requires the MOUNT removal and as such screws up the
costly quattro alignment, currently ~$230 at my dealer.
Re-install the MOUNT over the PLATE, push it all the way AWAY from the
center of the car and torque it with three NEW(!) locking nuts to spec.
Install the new top locking nut provided with the new shock and torque it to
spec.
Repeat all of the above for the second top mount.
Part IV
Replacing the rear springs and/or shocks.
The rear suspension is much easier to do. It does not require any special
tools (except for the spring compressor) and does not affect the alignment.
This means that you can do it separately from the front at a later time
should the need arise.
Remove the top three 13mm and the lower one 19mm locknuts and pull the strut
assembly out. Make sure not to disturb the ABS sensors in the hub or you
ABS will protest the sensor misalignment the next time you start up the car.
Secure the strut assembly in the vise and compress the spring. Undo the top
locknut with a box wrench while keeping the shaft from rotating with an
Allen key.
Unlike the front strut the rear one is integral. The spring sits on the
perch which is fed over the shock absorber tube. Carefully disassemble the
strut, taking notes of the ORIENTATION of the dimples and spring stops in
both the lower and the upper perches in reference to the shock position in
the body of the car. Otherwise you may end up with a different ride height
left to right.
Keep in mind that Bilstein has recently stopped cutting additional
adjustment grooves into which the steel ring for the lower perch goes. The
one remaining groove drops the car equipped with Eibach springs 10mm more in
the back than in the front.
You can address this issue in two ways. Either have a machine shop cut
several additional adjustment grooves in the body of the shock above the
existing groove or use a spacer ring. A set of two 50mm DIA x 12mm rings are
available from Eibach for ~$30.
Reassemble the strut by putting the new spring onto the new shock using the
existing bottom and top mounting perches and secure them with a NEW(!) top
locknut. Keep in mind that a lowering spring requires a shorter shock,
otherwise the shock will not be working in its optimal range or worse yet
may even brake.
Mount the strut into the car using all NEW(!) locknuts. Repeat the above for
the other side.
Part V
The Results.
Folks, By now you should have done all four corners of your suspension so
now it is time to lower your car onto the garage floor. If you lower the car
off the four jack stands directly onto the floor you are likely to put
strain on the suspension components, which in turn will throw your camber
reading off baseline. I used a very clever method suggested to me many years
ago by our esteemed Audi-Dudi (Jeff Goggin). You'll need 8 cheapest 1'x1'
vinyl tiles (the ones I found at Home Depot were 42 cents each). Smear some
common bearing grease onto the glossy surface of one tile and put the second
tile on top of it so that their glossy surfaces meet and are held together
by grease. Repeat that for the remaining tiles. Place the resulting 4
"sandwiches" under 4 wheels of your car and lower it onto the floor. The top
tiles will slightly slide sideways on the bottom ones each time you lower a
corner. In the end the car will rest in a position when the suspension is
not strained and you can accurately measure the alignment angles. You can
use my makeshift Camber gauge described in Part I to take measurements and
compare them to the ones that you should have recorded prior to lowering the
suspension.
==============================================================
Ride height.
When I had originally installed the Eibach/Bilstein suspension in my '97
UrS6, the front end dropped by 30mm whereas the rear dropped by 40mm.
OEM springs + shox:
FRONT Springs: Silver, Silver, Yellow (the softest available on the UrS)
FRONT Shocks: Boge, TurboGas 4A0 413 031 J (BOGE: 33-062 B)
REAR Springs: Green, Pink (the softest available on the UrS)
REAR Shocks: Boge, TurboGas 4A5 513 031 A (BOGE: 32-115 B)
FRONT L: 400mm; FRONT R: 405mm
REAR L: 400mm; REAR R: 405mm
Dead nuts level FRONT-REAR but sagging on the left.
Eibach springs + Bilstein Sport shox:
All Springs: Eibach Pro Kit (1529.140)
FRONT Shocks: Bilstein Sport (P36-0369), bump stop eliminated.
REAR Shocks: Bilstein Sport (B46-2066), bump stop shortened ~20mm.
FRONT L: 370mm; FRONT R: 370mm
REAR L: 360mm; REAR R: 360mm
Dead nuts level L-R but sagging in the rear.
==============================================================
Alignment.
Factory Spec for Camber: FRONT: -0.85oe (from -0.25oe to -1.25oe), max
permissible Delta 0.5oe REAR: -0.25oe (from 0.00oe to -0.50oe), max
permissible Delta 0.5oe
Alignment was done immediately:
FRONT Camber, both L and R: -1.2oe (slightly out of spec). The OEM camber
plates were retained, holes _were_not_ elongated.
FRONT Toe: dead nuts spec, set in the center of the tolerance allowance.
FRONT Caster: to spec, 0.5oe discrepancy RIGHT-LEFT (OK, I can live with
that).
REAR Camber and Toe: all dead nuts spec, set in the center of the tolerance
allowance.
==============================================================
Amendment of 02-02-2001 after the suspension was totally redone. All 4
tyres are at 35psi pressure.
Floor in the garage is tilted down from left to right 0.1oe. Camber before
the mod (actual - adjusted 0.1oe - in parenthesis):
FRONT L: -1.5oe(-1.4oe); FRONT R: -1.3oe(-1.4oe)
REAR L: -0.8oe(-0.7oe); REAR R: -0.6oe(-0.7oe)
FRONT: both top plates re-drilled 180oe and reversed. Additional Camber
found (plate moved 5mm outward). In addition the 3 holes in the top mount
were elongated. Camber after the mod (actual - adjusted 0.1oe - in
parenthesis):
FRONT L: -0.7oe(-0.6oe); FRONT R: -0.6oe(-0.7oe)
REAR L: -0.6oe(-0.5oe); REAR R: -0.3oe(-0.4oe)
REAR: the 50mm x 12mm steel spacers were installed under the spring perch
(courtesy of Eibach).
Ride height after the rear spacers were installed:
FRONT L: 365mm; FRONT R: 370mm
REAR L: 365mm; REAR R: 365mm
===============================================================
Conclusion.
As it was shown in Chapters I through V above, an UrS could be lowered w/o
sacrificing of the proper alignment and w/o installing some fancy
super-duper front Camber Plates, which were said to be of questionable
reliability and were rather expensive. However, as it is always the case,
here is a ...
*************************DISCLAIMER**********************************
the above procedure worked very well for my particular car. YMMV.
I would like to publicly acknowledge the help of:
- Peter Blaser for suggesting this brilliant idea of reversing and
re-drilling the plates in the first place.
- Jeff Goggin for the detailed and lengthy private post to me on how to do
alignment in your own garage.
- Frank Amoroso for immediately getting back to me on the cell phone with
the crucial and timely: "throw them the hell away altogether" to my question
on how the hell am I supposed to feed a ~40mm Bilstein shafts through the
~15mm hole in the OEM front speed bumps. :-)
--
Igor Kessel (igor at s-cars.org)
two turbo quattros
http://home.amexol.net/~ikessel/
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