Well, I don't know if it will happen this year or not (it's starting to
look like not; unforeseen life expenses will eat into your discretionary
budget <sigh>), but I'm definitely going to put a high end suspension on
my 1990 as my next major upgrade. I'm still not sure what it will be,
but it will almost certainly be either the Flyin' Miata AFCOs or the 949
Racing Club Sports. I'm a firm believer in "do it once, do it right" and
either of those will let me do anything I might ever want to do with my
Miata in the future.

I'm leaning towards the Club Sports, because while they are slightly
less adjustable in that they have one adjuster that is primarily rebound
and at the stiff end of its range adjusts the compression "knee point" a
little bit (as compared to the AFCOs with separate rebound and
compression adjustments), they are upgradeable to double-adjustable and
even triple-adjustable. Yes, I know that doesn't quite follow the rule I
just laid out, and I could just spend that money up front, but I know at
this point I simply don't know enough to use even the double adjustments
of the AFCO setup intelligently, whereas a coordinated single adjuster I
do think I could use to my benefit.

But what I wanted to talk about really was my fiendishly clever plan for
my car and its alignment, and what changes I'll make to it for the
winter months. Because the reality is that while I want an aggressive
street setup for the spring, summer and early fall, for the months of
November through March, I'm quite likely to want to take my Miata on
roads that have significant snow cover and in particular roads where the
snow is packed down in the centre of the lane and your tires drive down
ruts on either side.

Right: ground clearance. Setting the Miata to a ride height that is
appropriate for the most fun and performance on my 6ULs with Toyo T1R
tires in the summer is going to leave it critically short of ground
clearance once I want to get to the ski resorts (or even down my own
street after the sort of winter storms we're often receiving in
Vancouver these days; global warming isn't working out for us!). Heck,
even with my car at stock height (about 13.75" front and a little less
rear; I know my rear is drooping) I often have trouble.

So what I'd like to do is set up the car for summer driving, align it,
and then simply raise it up high in the winter. That is one thing that a
threaded-body coilover should make dead simple. But what would that do
to the alignment? Would the numbers that work in the summer move into a
range that isn't feasible in the winter? If I take the numbers I've seen
bandied around‹Icehawk's alignment for instance‹then I'd be running
about 12.75-13" front ride height and -1.5° front camber with rears at
13.25-13.5 and -2°. So what would that give me if I used the threaded
spring perches to raise the whole thing up 1.5" for the winter?

Enter Jyri J. Virkki and a web page that he created:

<http://virkki.com/jyri/miata/camber/>

At first, it wouldn't work in Safari on my Mac, but after emailing him,
he very kindly fixed it less than 12 hours after I first told him it
didn't work.

What I did was work backwards:

I set the ride height in each applet to my planned *winter* height
(because it only shows camber from static ride height into bump) and
then adjusted the static camber until I got a close match to my desired
summer camber at the summer ride height in the column of figures to the
right of the graph.

Bottom line, if I setup the car for front: 12.75"/-1.5°, rear:
13.25"/-2.0°, when I raise the car for winter, I'll get f:14.25"/-0.2°,
r:14.75"/-1.1°; which seems like it would be perfectly acceptable
numbers to run with 185/60-14 snow tires mounted on steel wheels (or
daisies if I can find a set).

The only thing that might need to be reset each fall and spring would be
front toe.

What do you guys think?

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>