|2005 Mustang Chassis
Harnesses the Beast Within
chassis and careful attention to vehicle dynamics give
the all-new Mustang world-class ride and handling.
The starting point is an
all-new, purpose-built, muscle-car platform with exceptional
body stiffness and a very high strength-to-weight ratio.
With this ultra-rigid structure, Mustang engineers could
tune spring, damping and bushing rates to a finer degree
than ever possible.
|Using computer-aided design
and engineering technology, the Mustang team took months
off the earliest phases of component development.
That gave driving dynamics
experts more time to work out final chassis tuning – and they
used it to deliver an unprecedented combination of road handling and
comfort in the 2005 Mustang.
|Track time – at drag
strips and on road courses – was a critical part of development,
as chassis engineers pushed prototypes to the limit in search of the
perfect power-and-handling blend.
|"We spent countless
hours refining this car on development drives and at the track,"
said Mark Rushbrook, vehicle development manager. "The car has
been to the Nelson Ledges road course in Ohio several times for 24-hour
runs and has spent months on our own straightaways and handling courses
at our proving grounds in Arizona, Michigan and Florida."
Street time was just as
important. Mustang is a muscle car designed for everyday driving,
and it must deliver a quiet, comfortable, reassuring ride in a real
world plagued by potholes and uncertain road conditions. By the time
testing is completed, prototypes of the new Mustang will have logged
nearly 1 million miles on streets, highways and tracks throughout
the United States, Canada and even Sweden in all types of weather.
|A quiet cabin – where
unwanted road and wind noise is supplanted by the signature growl
of a Mustang engine – was a top development priority. Computers
carefully mapped the natural vibrating frequencies of body components
to pinpoint areas where unwanted noise was transmitted. Based on this
data, components were modified or material was applied to quell the
unwanted noise. Despite the new, quieter interior, the car still has
plenty of "character." There will be no mistaking it for
something other than a Mustang.
|The result is a car that
delivers the edge – the performance characteristics Mustang
buyers demand – along with the smooth – a more civilized
environment that makes for a pleasant driving experience on long trips
or in more routine travel about town.
– Born to Run like a Mustang
|One of the more critical
development areas was the front suspension, where the
Mustang design team delivered a high degree of precision
handling, coupled with a smooth ride, all while harnessing
the power a top-of-the-line GT can deliver.
Engineers carefully examined
the BMW M3, a car believed by many to deliver just such
qualities, before they laid out the Mustang's suspension.
They used lessons learned from the M3 and the Lincoln
LS to create the new Mustang's chassis design.
Mustang engineers settled
on using a coil-over MacPherson strut front suspension
with reverse "L" lower control arms made of
lightweight I-section steel. MacPherson struts –
originally developed in the 1940s by Earl S. MacPherson,
a Ford engineer – are widely renowned for their
ability to deliver both comfort and control with reduced
|The L-shaped lower control
arms offer additional advantages over A-arm or wishbone-shaped suspension
components when it comes to blending sure handling with ride comfort.
A firm bushing is positioned at the point where the shorter forward
leg of the L-arm connects to the chassis to control side-to-side motion
and quicken steering response. The fore-and-aft movements are directed
through a softer, compliant bushing at the longer, rear L-arm leg,
which damps road shocks. This isolation is a direct benefit of the
reverse L-configuration of the control arms.
|Springs are mounted concentrically
on the MacPherson struts in a coil-over-shock configuration. The layout
allows the shocks to damp forces in the same vector as the spring,
cutting friction and enabling more precise shock-valve tuning. A stabilizer
bar – 34 mm on the GT and 28.6 mm for V-6 models – helps
limit body roll.
|At the core of Mustang’s advanced
new front suspension is groundbreaking manufacturing technology used
to produce steel control arms that actually weigh less than some comparable
|Employed for the first time
in a production vehicle, this new manufacturing technique allows two
C-section stampings to be assembled back-to-back with welded seams.
This creates an I-section profile that offers an exceptional strength-to-weight
ratio. Material is efficiently moved toward the edges of the control
arms for increased stiffness, while the center is kept thin to
|Reducing unsprung weight
– components that are positioned below the springs and shocks
– improves the suspension’s response to abrupt changes,
like pavement seams. Drivers will feel more connected to the road,
while enjoying a smoother, quieter ride.
|"Having too much unsprung
weight is like trying to play basketball in ski boots," said
Rushbrook. "Keeping the unsprung weight low gives the suspension
the quickness to stay firmly planted to the road."
|The new steering system
not only makes Mustang more enjoyable to drive on the open road, it
also greatly improves parking lot maneuverability. The rack-and-pinion
linkage provides crisp turn-in and excellent response, with a turning
circle nearly 3 feet smaller than the 2004 model.
– Mustang’s Solid New Design
|Working on a clean sheet
of paper, Mustang’s engineering team could have selected any
type of setup at the rear, including an independent suspension. So
why choose a solid rear axle? The answer lies in Mustang’s position
as America’s sports car.
|"We talked to a lot
of Mustang owners when we were developing this program," said
Hau Thai-Tang, chief nameplate engineer. "They are a very passionate
group, and a lot of them told us – very strongly – that
the all-new Mustang must have a solid rear axle."
|Although a mainstay of muscle-car
design, the solid axle hasn’t always been viewed as its strong
suit. Early hopped-up sedans often overwhelmed their leaf-spring live
axles, which weren’t designed for the demands of performance
driving. The slender leaf springs were prone to side sway in hard
maneuvers and to wind up and "hop" the rear wheels under
full throttle. The tendency of the low-grip bias-ply tires of the
day to lose traction and "burn rubber" actually was a blessing
in disguise, as it took pressure off the suspension.
|For 40 years, Mustangs have
featured ever-improving solid rear axle designs.
|For 2005, Mustang’s
rear suspension takes a completely different approach to combat wheel
hop. Engineers opted for a three-link architecture with a Panhard
rod that provides precise control of the rear axle. A central torque
control arm is fastened to the upper front end of the differential,
while trailing arms are located near each end of the axle.
|A lightweight, tubular Panhard
rod is parallel to the axle and attached at one end to the body and
at the other to the axle. It stabilizes the rear axle side-to-side
as the wheels move through jounce and rebound. It also firmly controls
the axle during hard cornering.
|Constant rate coil springs
and outboard shocks are tuned for a firm, yet compliant, ride. The
shocks are located on the outside of the rear structural rails, near
the wheels, reducing the lever effect of the axle and allowing more
precise, slightly softer tuning of the shock valves.
|The GT version of the car
incorporates a separate rear stabilizer bar to reduce body lean further.
|Previous Mustangs used a
simplified rear suspension linkage that acted on composite force vectors.
By using separate longitudinal and lateral links in the all-new Mustang,
engineers could isolate the forces acting on the rear axle and tune
the bushings accordingly. As a result, the axle is more precisely
controlled throughout its range of motion. Road shocks are isolated
and damped, and the solid lateral control of the rear axle reduces
body sway and improves control and stability over mid-corner bumps.
|The solid rear axle offers
several other advantages that play to Mustang’s strengths. It
is robust, maintains constant track, toe-in and camber relative to
the road surface, and it keeps body roll well under control.
|In short, the Mustang’s
sophisticated rear geometry provides handling precision and performance
worthy of a modern muscle car. But that doesn’t mean any of
the fun has been dialed out of the new model. Keeping enthusiasts
in mind, Ford chassis and powertrain engineers worked together to
make sure owners of the new Mustang still can "chirp" the
rear tires when the spirit moves them.
|Brakes – Adding
Whoa to the Go
|Bigger usually means better
when it comes to brakes, but that is only part of the
story behind the 2005 Mustang’s sophisticated standard
four-wheel-disc braking system.
|Along with Mustang’s
biggest-ever rotors and stiffest calipers, comes a new,
four-channel anti-lock braking system. Standard on GT
and optional on V-6, it enhances braking performance.
In addition to helping prevent wheel lock-up, the new
system has electronic brake force distribution, which
distributes braking power to the wheels where it can be
used most effectively.
|Dual piston aluminum floating
front calipers clamp down on 316 mm (12.4-inch) front
brake discs on GT models – an increase of more than
15 percent in rotor size. On the GT, the brakes have 14
percent more swept area than those of the previous model.
|These rotors are 30 mm thick
and are ventilated to provide consistent stopping power, even under
the strain of excessive heat induced by repeated hard braking. The
payoff comes in shorter stopping distances, better pedal feel and
longer pad and rotor life.
|The V-6 Mustangs get 293
mm (11.5-inch) ventilated rotors that also are 30 mm thick. This represents
a 6 percent increase in rotor size over the previous V-6 Mustang brakes.
|In the rear, the brake rotors
are 300 mm (11.8 inches) in diameter – more than 12 percent
larger than the previous Mustang – and 19 mm thick. Rear rotors
are vented on both the GT and V-6. Single-piston calipers sweep 18
percent more area than the rear brakes on the previous Mustang.
New Mustang Wheels and Tires
|No muscle car deserves the
title unless suited up with the proper wheels and tires,
and the new Mustang won’t leave the factory half-dressed.
The array of wheels available on the 2005 Mustang is engineered
to meet demanding performance requirements.
|The standard 17-inch wheels
on Mustang GT are 8 inches wide and equipped with Pirelli
P235/55ZR17 W-speed-rated all-season performance tires
for year-round driving.
|V-6 models have 7-inch-wide,
16-inch wheels. As with the Mustang GT, all-season rubber
is standard, with a slightly higher profile S-rated BF
Goodrich tire, sized at P215/65R16. These tires are designed
to offer long wear without compromising performance.
|In concert with the ABS and traction control systems,
the new, all-season tires make Mustang more practical in rain, ice
or snow. On dry pavement, they provide an exceptionally engaging driving
experience with high overall grip and good steering response.
Aesthetically, street rodders long have known that larger wheels
and tires better fill the car’s wheel wells, adding meat to
the muscle. The 2005 Mustang’s tires boast more sidewall than
many other sports cars, enhancing the muscle car look and providing
a better match for this vehicle’s blend of power and handling.