At 02:09 PM 2/9/99 -0500, John Suchak wrote:
>As long as we're on the subject of coil springs, what's the consensus on
lowering the front of a Spitfire? I'd like to drop it about 1" to 2". Is
there a source for shorter springs?
Stock springs for a pre-71 Spit will ride lower, but mine is TOO low, see
below. Ed Hamilton's '80 Spit had Comp springs (from VB I think he said)
and his had a rake also, but it rode very stiffly.
>Can the coils be cut without compromising their integrity?
Use a cutting wheel, try not to heat the springs up too much so they don't
lose their 'springiness'. Again, being careful of heat, you can sand flats
on the top& bottom coils.
>Are there any alignment ramifications associated with such an act?
Well yeah, you'll have to align the car after doing the spring work. You'll
likely end up with more negative camber (as opposed to the POSITIVE factory
setting). I'm running neg .5 degree. When the camber changes, the toe
must be reset.
The suspension engineer that inhabits the Lotus-Cars-List recommends that
the steering rack position be changed as well, the object being the tie
rods should be parallel with the ground.
Below is a treatise on springs I archived from the Spitfire Enthusiasts List:
>From: cshore@harland.net
>Subject: Re: [Spring free length calcs}
>
>
>
>Notice that the Spitfire front springs sit in seats or pockets that hold
>the springs in position, concentric with the shock absorbers. The lower
>pockets are part of the shock absorber body, and the top pockets are bolted
>into the front suspension subframe where the top shock absorber mount
>attaches. If you use flat spacers, there will be nothing to retain the
>springs. Do not use 'between the coil' spacers, they will cause high
>localized bending loads in the spring wire, leading to premature sagging or
>even spring failure. You could make flat spacers that fit between the upper
>spring pockets and the front suspension subframe, using the spring pockets
>as a template for the holes.
>
>Another cheap way is to take your springs to a local spring shop ( yellow
>pages! ), and have the free length changed.
>
>1) With the current springs installed, measure the compressed spring
>length.
>2) Jack or raise ( or add weights if you are lowering ) to the desired ride
>height.
>3) Measure the new spring length.
>4) Divide the original length by the new length to get the ratio.
>5) Remove the springs from the car.
>6) Measure the free length of the springs.
>7) Multiply the free length by the ratio you calculated in step 4.
>
>That is the new free length that you want the spring shop to change them
>to. The spring rate will not change much, since that is determined by the
>wire diameter, wire material, and ( uncoiled ) wire length.
>
>Measure carefully, every inch of spring length means about 11/2 - 2 inches
>of ride height.
>
>By the way, if you lower the front of a Spitfire too much, the stock shock
>absorbers will bottom out. This can quickly ruin a set of expensive Koni's.
>There used to be an extension adaptor, but I haven't seen them for sale in
>years.
>
>The best long term solution is a shock with a threaded body and adjustable
>spring mount, but that ain't cheap.
+++++++
I'm still trying to get my Spit to stop scraping the ground at the sway bar
u-bolts. I'm trying a 1/2" spacer between the spring seat & body. This
shopuld make the sills on my car nearly level (unladen).
Gotta go back to the garage now.
Atwell Haines
'79 Spitfire
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