Miata Mailing List: February 1993, Message #28
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   From: (none)
Subject: Millen sway bars: installation and impressions
   Date: (none)




Last Fall I installed some Rod Millen anti-sway bars and springs, I wrote
up the following to submit to our local newsletter.  Maybe it will be of
value to someone considering doing the same:


PS: During the winter I installed an aftermarket power window kit.  If there
is any interest in this, I can post the results.

Thanks, and Spring is just around the corner!
jdm
================================================================================
            _
            /        Jeff Maurer, Sr. Analyst
     _  ___/ _ __   Service Applications, Sequent Computer Systems, Inc.
     / /  / / / /  Uucp: ...!uunet!sequent!jdm
    / /__/_/   /  Internet: jdm@sequent.com
 __/             (503) 578-5062
"The more things stay the same, the less they change."
Spinal Tap



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Millen Springs and Anti-sway Bars

The Millen springs are shot-peened and powder-coated.  They are shorter,
stiffer, and of a higher rate than the stock springs.  The sway bars
have forged ends.  The front bar is two-way adjustable and the rear
bar is three way adjustable.  These are powder coated in light blue as
well.  They come with new brackets and silicone-impregnated urethane
bushings.  Overall, the quality appears high.  Millen charges $359 for 
springs and sway bars.  This is a very competitive price since Eibach, 
Jackson, and others charge nearly this much for the bars or the springs alone.

For the home mechanic, expect to spend between 4 and 10 hours of work to
install both the springs and the sway bars.  I came out on the high side
because I tend to proceed with these things slowly and methodically and because
I don't have any air tools at my disposal.  Installation of the sway bars
is trivial if you are doing the springs anyway.  Tools required:

	o Metric socket set
	o Metric combination wrench set
	o Mazda Miata Shop Manual
	o Torque wrench
	o Tire wrench
	o Jackstands
	o Trolley jack
	o McPherson strut style spring compressor
	o Mazda upper ball joint separator (optional, see note below)

You will require a sturdy spring compressor which can be rented for
between $10 and $15 per day.  In my experience, the best spring compressor
has a single bolt adjustment, and is shaped like two capital 'A's hinged at
the apexes.  The jaws clamp the spring on opposite sides.  The other alternative
is a pair of heavy bolts with small jaws at either end.  These are used in
pairs on either side of the spring, and tightened alternately (and very
slowly when done by hand!)  Baxter Auto Parts has a better than average
pair of compressors (the second kind)  for sale for $35.  Avoid cheap ones, 
the consequences of the compressor failing under pressure are serious!

The Miata Shop Manual specifies a special ball joint separator for the upper
ball joint on the front wheel.  This is necessary because the shock tower,
once loosened top and bottom, can't be tilted to clear the fender well unless
the upper A-arm is lowered.  Unfortunately, all of the decent universal
ball joint separators that I tried are too long to fit in the cramped
space between the upper and lower A-arms.  You can avoid the whole issue
by removing the two inside bolts that retain the lower A-arm as I did.
These also are responsible for adjusting the camber and caster though, so
take careful note of the settings before you loosen them.  You should also
consider having the car realigned after you're done.

When you've removed the shock towers and dropped the A-arms, you might
take this opportunity to clean out the wheel well and spray some undercoating
in this area.  Be sure to mask bolt and screw heads, and to cover the
disc brake assembly.

The Millen instructions consist of a single sheet of terse hints for
installing the anti-sway bars.  There are no instructions for installing
the springs.  Follow the shop manual instructions for the front and
rear suspension disassembly, and the sway bar installation will be self-
evident.  One important note, the springs are marked front and rear with
VERY tiny writing (1/16" high).  Look for the Millen logo on the coils,
and following it will be either an `r' or an `f'.  As a rule of thumb, the
taller springs go in the back.

Installation was clean and straightforward.  The result?  The car is
about an inch lower.  You don't really notice the difference until you park 
it next to a stock Miata, then you begin to notice how much space there 
really IS in the stock wheel wells between the wheels and the fender.  
The car really looks better lowered a bit (this is with stock alloys and 
tires).  The ride quality is definitely firmer.  I think it's too firm 
for _really_ rough roads, but for me the gains outweigh the disadvantages.

I currently have the sway bars set at the first position for the front, and
the second for the rear. The car corners much flatter, steering transitions
are quicker, and the overall balance of the car hasn't changed noticably.

In all, the Millen sway bars and springs are highly recommended.  The result
is still very "streetable", but much tighter.  If you decide to install new
springs and/or sway bars, and you have questions or run into problems,
feel free to give me a call.


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