Spider front springs, ride-heights and alignments

[JHertzman@domain.elided]

In AD7-768 Godfrey DiGiorgi wrote "Thanks for the correction on the upper 
control arms and such with the early and late Spiders, but it leaves me with 
a question. If they didn't change the control arms and they did change the 
ride height via different springs, spacers, or whatever, did anything else 
change to accomodate the different front end geometry that the increased 
ride-height effected?"

Reasonable question. One knows that (within limits) caster, camber and toe 
are interrelated such that if one is fiddled another can be faddled to 
compensate, but the numbers should be on record somewhere. 

I do have the old "Giulia and 1750 Wheels, Suspension and Front End Geometry 
Manual" #1507, and by happenstance also have the shop manual PA3474800000000 
for the 1986 Spider (50 State Version), ergo not Euro.

With the cars loaded to specified values the front end trim value (the 
difference between the height of the wishbone shaft and that of the steering 
knuckle) is given as 19 to 29 mm for the 1750 Spider, and as 24 +/- 5 mm for 
the 1986 Spider. The rear end trim value (clearance between buffer and the 
buffer pad on rear axle) is given as 28 to 38 mm for the 1750, and as 33 +/- 
5 mm for the 1986. Caster, camber and toe are the same for both cars, with 
the exception that the one is given as a range while the other is given as 
the range midpoint +/- half the difference. 

This does not exclude either of two possibilities:
(1) the specs went up and down like yo-yos in the interim, or
(2) we have firm knowledge based on recollections of two used cars, either or 
both of which may have been "improved".

The only difference I could find between the 1750 and the 1986 was in the 
static loading for measurement; the sandbags on both sides of the front floor 
were 25 kg in both cases, but the sandbags in the seats were to be 45 kg for 
the 1750 and 50 kg for the 1986 Spider.

Does anyone have the numbers from factory manuals for years closer to the 
"about 1975" raising of the front end? Say, 1973 and 1978? Eyeballing a 
twenty-year old car next to a thirty-year old car, or recollections from 
having done so a decade ago, would not carry the same weight.

Cordially,

John H.
Raleigh, N.C.

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