Modified Front and Rear Strut Housings and Carrera Insert
wheel loading changes which can cause loss of adhesion
in the presence of bumps during cornering. The optimum
compromise will be somewhat stiffer for a smooth track
than for a rough track, in general. However, making
changes in spring rates gets rather complex for the typical
SCCA racer and should not be necessary in most cases.
Adjustable shocks sound like a relatively good idea, but
in practice they are not practical, particularly with a
strut type suspension. Shocks which must be collapsed
in order to adjust them require removal of the spring in
order to collapse them. Also, most adjustable shocks are
only adjustable for rebound damping. This works fine
for ride control, but for racing they should be relatively
loose on rebound in order to let the spring push the tire
back down onto the ground. In racing the compression
stroke on the shocks becomes more important, in order
to keep the tire from leaving the ground on the upward
stroke. Thus, a shockabsorber which works well for
street
use will not necessarily make a good racing shock, and
vice versa. Also, it must be remembered that the primary
suspension element is the spring and radically altering the
damping will not compensate for the wrong selection of
spring rates. Thus, for SCCA production racing a good
quality, non-adjustable racing shock, which is calibrated
for the approximate load and spring rate of the
X1/9,
should be adequate for most racing conditions. The
springs should be changed to a higher rate spring, with
an adjustable lower spring perch, to allow ride height ad-
justment and balancing of suspension loads from corner
to corner. The following paragraphs will describe rear
strut modifications required to use Carrera
1974F
coil-
over shock conversion kits and Carrera
3263.5-F
strut
inserts. The modified parts are included in PBS Kit
Number
2.
Completely disassemble the rear strut assemblies. The
only part which will be used is the outer strut housing.
Cut the stock spring perch off from the strut housing.
The heavy walled threaded tube supplied in the
Car-
rera coil-over conversion is longer and hence heavier than
front
and Rear Anti-Roll Bars
necessary. This tube can be cut to a length of
2-718
inches.
Mount the threaded tube
3
inches above the suspen-
sion bracket on the strut housing.
If Carrera
3263.5-F
strut inserts are used, it is recom-
mended that an indexing washer be welded on the bottom
of the insert per Drawing
1.
This indexes positively inside
the bottom of the strut housing in the same fashion as
the stock insert and precludes any possibility of undesired
motion at this point.
Rear Adjustable
Camber
Plates
Adjustable camber plate assemblies are recommended for
the
X1/9
for racing because they allow relatively simple
camber adjustment which will be useful in chassis tuning.
Also, the camber plate is thinner than the stock attach-
ment and allows the car to be lowered farther without
limiting travel. The following paragraphs describe the in-
stallation of a Carrera
1875HF
camber plate assembly.
These are included in PBS Kit Number
2.
Referring to the pictures, cut and fit doublers from
1-112
inches wide by
118
inch steel, on top of the strut
Complete Strut Assemblies With Carrera Coils and Camber Plates
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