© 1998-
Although the above described suspension is ideal from a ride and tire wear standpoint
during highway driving, it is less than desirable, perhaps even
dangerous during
tight cornering at moderate to higher speeds. During a turn the center of gravity
is shifted away from the direction of the turn in proportion to the tightness of
the turn and the speed of the car -
To avoid roll-
the road
during cornering, which allows the tire tread to have better or full road contact
even while the car body/frame sways (a good stabilizer bar -
While the suspension described above would be ideal for a sports car, it would be
less than desirable for a highway car since 
every bump the car encounters would
cause the wheel to change angle with the road as can be seen in the illustration
to the right. This would cause more tire wear than a design that keeps the wheels
parallel to the frame during bumps. In addition, in these circumstances it can be
seen that less tire tread is in contact with the road while going over bumps. This
is not usually a problem from a control standpoint during straight forward driving,
but can cause problems on washboard roads or otherwise very uneven road surfaces.
All of this extra movement also has effect on the steering linkages which can cause
a change in the right/left angle of the wheel with each bump which is referred to
as "bump steer". Engineers need to take all this and more into account in their
design. And, as mentioned previously, a great deal of compromise usually takes place
between ride, tire wear, highway use, cornering/ maneuvering ability, and cost of
building and maintaining the vehicle. On our Falcons (and early Mustangs), Ford engineers
decided the cars would generally be used for highway and around town use and took
a "better ride" and "cost effective" approach in their design.
General Overview
The front suspension, steering and front brakes on any car are highly interrelated and it is difficult to discuss one without mentioning the other. However, I will make the main focus of this series of web pages the front suspension alone. While they will be mentioned briefly here, I will cover steering and brakes in greater depth in other web pages.
Designing a front suspension for any car involves far more than is immediately obvious.
The rear suspension on our Falcons is fairly straight forward and simple. Generally,
it only needs to take into account up and down travel. The front suspension, on the
other hand, must take several movements and handling characteristics into account
when engineers start to design it. The ideal front suspension would be able to handle
bumps and poor road conditions while maintaining optimal tire tread contact with
the road during cornering and maneuvering, while also keeping an accurate alignment
between both front wheels and with the rear wheels during straight driving as well
as during turns. All the while giving a velvet smooth ride. Designing such a suspension
can be a very daunting task for engineers and often, as with most other things in
life, it involves a large degree of compromise. For example, if you want a suspension
that handles well, you usually need to put up with a rougher ride and less than optimal
tire wear. Conversely, if you want a velvety smooth ride and great highway tire wear
you generally need to put up with less than optimal handling. A true high performance
suspension will almost always cost considerably more and be more complex than a suspension
that will simply get the job done . Unfortunately, from a handling standpoint,
Ford engineers seem to have taken the get the job done attitude when designing
our Falcon (and early Mustang) suspension systems. While they perform adequately
in every-
Illustration from the 1964 Falcon Shop Manual
Used pursuant to permission granted by Ford Motor Company
The front suspension on our Falcons consists of the following: An upper control arm
(red arrow in photo), a spindle (that the 
brake assembly & wheel/tire is mounted
to -
This shows the entire front suspension and steering after removal from the car. The
individual parts are highlighted in the right photo: Upper control arms (red), spindles
with brake assembly attached (dark blue), lower control arms (green), strut rods
(yellow), stabilizer bar (pink), springs -
Operation & Modifications
As discussed above, engineers design a front suspension differently for a sports car than they do for a luxury highway car. If a car were only to be driven on the highway and never need to deal with any real cornering, engineers would design the suspension so that the tire would stay parallel to the frame of the car as the wheel is forced up and down with road bumps as can be seen in the three illustrations below.
The above four photos are of my '64 Sprint's suspension which were taken during disassembly after the spring, strut rod, and stabilizer bar were removed and show different amounts of front suspension compression. By looking at all four photos it is easy to see that the wheel maintains a position almost parallel to the frame of the car in its complete movement from full extension to full compression As discussed above this is generally fine for around town and highway use, but does not perform as well in tight cornering situations such as unexpectedly tight freeway off ramps, higher speed roads through mountainous terrain, or for higher performance sporty cars.
The Shelby Modification
When Carol Shelby was working on the Shelby Mustang he recognized that the car didn't
corner as well as it could due to the geometry of 
the front suspension. Since a
complete redesign of the suspension would be very expensive, Shelby elected to simply
change the geometry of the upper control arm (see illustration to the right). By
lowering the mounting of the upper control arm to the frame, the operating angle
of the upper arm was changed. In the illustration to the right, if the black arm
represents the original "at rest" angle of the arm, when the arm is moved upward
(due to a bump or a sway) to the height of the red arm, the amount the outer edge
of the arm is moved inward in minimal (value A). However, if the arm angle is changed
such that the new "at rest" angle of the arm is represented by the red arm in the
illustration, then when the arm is forced up (due to a bump or a sway) to the height
of the blue arm, then the outer edge of the arm is moved inward a great deal more
(value B). As discussed above, doing this will help the wheel maintain better tread
contact with the road during turn sway. This is how Carol Shelby improved the handling
of the famous Shelby Mustang. Fortunately for Falcon owners, the Shelby Mustang has
essentially the same suspension as a '64 or '65 Falcon, so the principles are the
same for the Falcon. (Note on the blue arm in the illustration the angle of the ball
joint stud -
In addition to better suspension geometry and tire tread contact with the road, lowering
the mounting of the upper control arm also results in lowering the front end. Since
the upper arm will pivot on the spring perch, physically moving the attach point
of 
the upper control arm to a lower position on the frame will result in the outer
edge of the upper arm moving upwards in relation to the frame. Since the outer edge
of the upper control arm remains at a relatively constant height from the road (assuming
constant tire inflation), if the outer edge of the arm moves upward in relation to
the road, then the frame must drop in relation to the road. Thus, the entire front
end of the car lowers. This also improves handling and cornering since lowering the
center of gravity will make a car inherently more stable in turns and have less tendency
toward rolling over.
The Shelby Mod calls for the upper control arm mounts to be lowered 1" and moved
aft (toward the rear of the car) 1/8" (see 
illustration). If you plan to make this
modification these measurements must be exact! I have heard there are sources for
a template for this mod but I have been unable to locate one myself. While you can
make the measurements yourself and mark them directly on your car frame and drill
from there, I recommend using a pre-
As alluded to above, the Shelby Mod is not without its concerns. While it does make
the car handle much better, there are at least three down sides. The first and probably
least concern is that many places refuse to even attempt to align a car that has
been lowered or has had the front end otherwise modified; however, after quite a
few phone calls I was able to find two or three places that would, but they told
me up front that it would be on an hourly rate instead of their usual flat rate for
an 
alignment since it usually takes more time to get an accurate alignment after
such modifications. As discussed above, a second, more major concern with the Shelby
mod is the new angle of the ball joint stud to the arm when the arm is at the full
up stop (hitting the frame bumper). At this angle the ball joint is near the limit
of its travel. Some have felt that with the ball joint operating at or near its limit
that it could eventually be stressed to the point of breaking and snapping off, which,
of course, would likely cause loss of control of the car. In answer, several companies
have introduced a kit to remedy the ball joint angle problem. The kit replaces the
ball joint on the upper arm with a heavier duty one and the kit has a wedge that
fits in between the upper arm and the ball joint that improves the operating angle
of the ball joint with the arm at the new steeper angle. This wedge tapers from zero
on the inside of the ball joint to 5/8" on the outside of the ball joint (see photo
at left). To make up for the 5/8" width of the wedge the upper arm is lowered an
additional 5/8" or 1 5/8" total and still 1/8" aft. The place I bought mine from
calls the kit a "Negative Wedge Camber" kit and installation of this kit will be
covered later in this series.
The third concern with these mods, especially the Negative Wedge Camber kit, is that
with the arm at a steeper angle at rest, the outside edge of the arm 
is now much
closer to the frame bumper and bottoming out becomes a fairly common occurrence rather
than an occasional one. As can be seen in the illustration to the right, if the black
arm represents the original design "at rest" angle, the distance from the top of
the arm to the frame bumper is a fair distance and is represented by value A. As
discussed above, when the arm is mounted lower on the frame it will pivot on the
spring perch and force the outside edge of the arm upward as represented by the red
arm in the illustration. Note the new distance between the red arm and the frame
bumper is now much less than the original stock location and is represented by value
B. (As a note, the blue arm in the illustration is simply to illustrate what would
happen if you raised the mounting point of the upper arm instead of lowering it and
to further illustrate that arm will pivot on the spring perch mount when the mounting
point of the arm is moved.) As mentioned, the Shelby Mod lowers the arm one inch,
but the Negative Wedge Camber kit lowers it 1 5/8" which raises the outer edge of
the arm even more than the Shelby Mod. If you choose to do either of these mods make
sure your frame bumpers are in good shape or when you do bottom out (which you will)
your upper control arms will be hitting the frame directly. Replacing the bumpers
(which will be covered later) is not difficult if you are doing this mod since the
springs need to be removed during this procedure anyway. An additional consideration
if you decide to do either of these mods is to install heavy duty stiffer shock absorbers
which will help to minimize bottoming out, albeit at some expense in ride comfort.
Should you modify your Falcon (or Mustang) in this manner? As with most things it
depends on what you plan to do with your car and how you normally drive it. If you
plan to race the car (race track type racing that is, not just straight ahead drag
racing) then the decision would probably be a definite yes. If you are a very cautious,
only around town and normal highway driver, then the decision most likely would be
no. If you are an aggressive assertive driver who likes to go fast and take corners
and off ramps at a quick pace, or one who is required to drive canyon-
A side benefit of either of these mods is that of aesthetics. Few will dispute the fact that a '64 or '65 Falcon looks like it sits nose high. It has always looked a bit funny to me. The lowering that happens when you do either of these mods improves the looks of the car, in my opinion, 100% or more. The car looks more like what one would have expected it to look like from the factory. It should be noted, however, that if you are looking to lower the car simply for aesthetics, "drop spindles" are available. These "drop spindles" simply raise the mounting location of the actual bearing spindle on the spindle proper which lowers the front end of the car without altering the operating geometry of the front suspension.
This is the end of the Front Suspension Edition
Part One
Feel free to save this page to your computer for your personal use and future reference-
If you have comments or suggestions, email me at joe@joesfalcon.com
Front
Suspension
Part 1
