If the car wants to get loose on you while you corner, there are two major
changes that must be made.
When I first got my spit, I could easily loop it around on any given corner,
especially if driving ham fisted or heavy footed. It didn't take much to
fix this problem though.
The first major change is to go to wider tires. Since you plan on
autocrossing, this is already on your agenda, I would assume. I am running
185/60-13's Yokohama's in FSP and am doing well enough to win class over
several other brit and japanese cars, even though the tires are well past
their prime. I am using TR7 wheels for width, but they worked well enough
on the 76 spit wheels as well. This somewhat solves the problem.
The second major change to eliminate the tendency to see your ass before
your face involves fixing the front suspension. If you want to learn the
specifics, see Carol Smith's Tune to Win, but sufficient to say, the front
spit springs need to substantially be stiffened. Depending on the ideal
wheel rate, an obtuse idea to begin with, the spring rates need to increase.
Assuming a moderate wheel rate of 150-180, the spitfire with a 1.6 squared
motion ratio will require something in the vicinity of 550 lb/inch springs
in the front. I happened across a set of 480 lb springs that are nearly
stiff enough. The question to be asked is whether your desire is to win at
autox or to have fun, because these springs have made gentle cruises far
less gentle. I would go no less than 350, with the rest inideally made up
with tire pressure adjustments.
Further, the front and rear should be as low as possible, especially the
rear. Find the next, most worn out rear spring you can find, this is best,
contrary to what you expect. The other option would be to go with Joe
Currey's camber compensator.
Just some suggestions that should help. Have fun,
jim
PS, the rear sway bar will only intensify the oversteer tendency unless you
compensate with altered spring rates all around.
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