~ I've cracked several a-arms on my sprite when using tube shocks.
So have I; I've also had the upper bolt snap off while driving.
The shop I bought it from replaced it, and gave me some technical
advice that helped me later.
The worst thing you can do with those tube shock kits is use
the existing holes in the A-arm. For ease of manufacture,
the lower A-arm in Spridgets has holes drilled for mounting
the anti-roll bar link in both sides of the A-arm. Most people
do what I did and bolted the shock absorber to the lower A-arm
using those holes.
The problem is, Werace specs shocks (or did back then) that
were just slightly too long for that location. So they provided
a template (which of course I foolishly ignored the first time
I installed the shocks) that shows you where to drill the holes
for the lower shock absorber mount. It's about 3/8" to 1/2"
outboard of the factory sway-bar holes. This gives just enough
of a geometry change that the shocks don't bottom out on full
bump. That's the problem, BTW -- when you hit full compression,
the shocks close up before the rest of the suspension does, and
you end up transmitting road shocks through the lower A-arm.
I pulled my front suspension apart, drilled the holes much more
carefully in the new lower A-arms, and reinstalled the shocks with
stock springs and a stiffer front anti-roll bar (I'd previously
been using stiffer "autocross" springs, which lowered the front
about an inch -- just what the Midget needs, less ground clearance!)
The bigger front bar (3/4" from FASPEC), stock springs, and Werace
tube shocks made a phenomenal improvement in the car's handling,
and I never had cracks again for as long as I owned the car (though
that's not saying much... see below).
~ I don't believe that factory a-arms are really suitable for
~ these conversions.
I don't know how long that tech tip would have worked, as the
Midget on which I'd installed the Werace kit was totalled while
parked exactly ten months later (and exactly one year to the DAY
after I took it down to rebuild the front end). Sigh.
~ My suggestion, if your racing, constantly inspecting anyway,
~ and believe this enhances your performance, well, you can
~ judge the risks for yourself. I think the conversion works better
~ on race cars since the pothole problem is less severe.
Also because most race cars have other re-engineering done to
the suspension to make the tube-shock conversion work. You will
want to ensure that there is travel left in the shocks after you
bottom out on the bump stops; this may (in appropriate classes,
of course) require moving some of the suspension pick-up points.
Don't know how you'd go about doing that on a Spridget; move the
upper link inboard and up, I guess, would be easiest. That'd
give you more negative camber, more camber gain, but I'm not
sure what it'd do to suspension travel; it seems like it would
reduce it, so it probably does -- not because it seems like it
does, but because I've observed that whenever I make a guess
about suspension, I end up reversing it because I know suspension
is so non-intuitive, and then THAT ends up being wrong too. :-)
~ But, if your just driving the car around town, properly
~ rebuilt or new lever shocks actually work pretty well and
~ do not cause the a-arms to crack.
Agreed. The lever shocks work within the limits of the rest of
the suspension, as long as they're fresh and you don't fill them
with motor oil or anything else that will eat the seals.
~ I would take the tube
~ shocks off (I did :-) ) and go with the originally designed
~ setup. Put on a sway bar if you want to tighten up the handling.
Bigger sway bars are a win on Midgets and MGBs both. MGB tube shocks
use a completely different setup that is very effective but looks as
though it might have its own flaws. I'm planning to install the
uprated shock valves in my MGB. Hmmm, maybe this week, before the
tour...?
~ In short, for a daily driver 'round town car, I think the front end tube
~ shock conversion is a very poor idea.
I don't know that I'd call it *very* poor, but the installation is
critical, paying attention to suspension travel and type of roads
you actually use. A good stock front suspension is certainly simpler
and actually more robust, though the faster response of modern
shocks gives a drastically different feel to the Midget.
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