|2-door coupe, production car
|Miles Per Gallon:
|500 bhp @ ---- rpm
|475 lb-ft @ ---- rpm
|f: 61.9 / r: 62.5 in
|--.- sec @ --- mph
|Braking, 60-0 mph:
|NŁrburgring Lap Time:
A major goal set for the Shelby GT500 was to raise the handling to a new level. An easy road to success would have been to simply let Ford Special Vehicle Team chassis engineers tweak the critically acclaimed Mustang GT and have motorsports legend Carroll Shelby put his stamp on it.
"It all depends on what youíre satisfied with," says Tom Chapman, SVT Vehicle Dynamics Supervisor. "If you just want to make the Mustang live a bit more happily with a 60-percent increase in engine output, itís fairly simple to do. If you want it to equal the handling of the Mustang GT despite a larger displacement engine, that takes a bit more work.
"But if you want to hold it up to a whole new set of standards and be worthy of the Shelby GT500 name, then you better be prepared to roll up your sleeves."
The GT500 retains the Mustangís suspension setup. In the front, there are coil-over MacPherson struts with reverse "L" lower control arms made of lightweight I-section steel. In the rear, thereís a three-link live axle with coil springs, Panhard rod, outboard shocks and stabilizer bar.
Because of its larger engine, the Shelby GT500 coupe has more weight over the front wheels than does the standard Mustang GT coupe. On the GT500, 57 percent of the weight is in the front and 43 percent is in the back. In comparison, on the Mustang GT 56 percent of the weight is in the front and 44 percent is in the back. Weight distribution of GT500 convertible matches the Mustang GT coupe due to the power-top mechanism behind the passenger compartment.
While a heavier nose generally disposes a car to understeer or "push," the Special Vehicle Teamís engineers were able to retain neutral handling with the Shelby GT500 through the use of stiffer stabilizer bars. In addition, the rear bar of the GT500 is larger than that of the Mustang GT.
The GT500 uses a 34-millimeter tubular front stabilizer bar. Coupe versions of the GT500 sport a 24-millimeter rear bar, while convertibles come with a 20-millimeter bar.
"Stiffer stabilizer bars provide reduced roll and deliver a more aggressive handling balance," says SVT Vehicle Dynamics Engineer Dean Martin. "Weíve also given the GT500 higher spring rates at both ends to handle the greater mass of the car and also to reduce roll."
The Shelby GT500 sports Brembo front brakes with four-piston calipers and vented 14-inch discs. In the back, GT500 carries over the Mustang GTís 11.8-inch vented single-piston caliper rear-disc setup with unique pad material.
"We choose a friction material that will provide good track-day performance for the customer and still deliver satisfactory parking-brake performance and quiet operation," says Chapman.
Tires Manage Balance of Power
The GT500 sits on four 18-inch x 9.5-inch wheels, wearing 255/45ZR18 tires on the front and larger 285/40ZR18 tires on the rear.
"Larger rears help get the engineís immense power to the ground better when accelerating off the line," says Martin. "They also improve handling balance when youíre powering away from the apex of a turn on the race track using as much torque and horsepower as the GT500 has."
Putting a Fine Edge on the Steering
The 2007 Shelby GT500 adds a brace that connects the rear lower arm bushings side to side. This was added to improve durability and steering feel.
A unique steering pump is used and the steering gear utilizes a unique torsion bar. Again, these work to improve steering feel and precision.
"We wanted to make sure the changes we made met enthusiast customer demands," Chapman says. "So we took our engineering cars not only to the test track, but to real-world drive routes and race tracks to make doubly sure that the GT500 would live up to the expectations."
SVT tested the 2007 Shelby GT500 at Grattan and GingerMan in Michigan, Nelson Ledges in Ohio and Las Vegas International Speedway. How long did they run?
"Long enough that we were satisfied," says Chapman. "And long enough to bring a smile to Carroll Shelbyís face."
Just as the big-block GT500 from 1968 was a step up from the GT350, the 2007 Ford Shelby GT500ís 500 horsepower, 5.4-liter V-8 is a step up from the 4.6-liter V-8 used in yesterdayís SVT Mustang Cobra.
Not coincidentally, the 2007 Shelby GT500 sports the largest displacement engine installed in a volume version of the Mustang since 1973.
The 1995 SVT Mustang Cobra R used a 5.8-liter 300 horsepower overhead valve V-8, and 250 units were produced. The 2000 SVT Mustang Cobra R used a 385 horsepower 5.4-liter dual overhead cam V-8, and a limited run of 300 cars were produced.
While the big block, overhead cams and four valves per cylinder contribute significantly to the 500-horsepower output of the 2007 Shelby GT500ís 5.4-liter V-8, a Roots-type supercharger and intercooler are the icing on the cake. In fact, the configuration is similar to the Ford GT supercar, offering the right combination of classic Ford big-block power and modern technology. Using the Ford GT as a blueprint, SVT has given the GT500 more total horsepower than any factory Mustang in the carís celebrated history.
"The Shelby GT500 delivers on the essence of two great names in Ford performance Ė a mix of SVTís modern-day experience with supercharging and the Shelby GT500ís heritage of big-block power," says Jay OíConnell, SVT chief vehicle engineer.
With the stout cast-iron, 5.4-liter Triton V-8 engine as a starting point, the Shelby GT500 adds a Roots-type 8.5-pounds-per-square-inch Eaton supercharger and water-to-air intercooler producing 500-horsepower.
"A screw-type supercharger that we use in the Ford GT gives you a little more top end, and the Roots type is a little fatter in the midrange," says OíConnell. Given that the GT500 will be used as a daily driver far more than the Ford GT is, itís the ideal choice."
Adding forced-induction power is more than just a bolt-on proposition. The engineís internals need upgrading for the sake of strength and durability. To that end, the Shelby GT500ís powerplant benefits from unique connecting rods and forged pistons to handle the extra strain on the lower end of the block.
"The entire induction system is unique," says OíConnell. "That includes the intake, intercooler, fuel supply Ė everything."
The all-new intake manifold helps to channel the supercharged fuel-air mixture into the cylinders. The low-profile manifold design also effectively packages the entire induction system under the GT500ís special air-extractor hood. Fuel comes from a dual-bore electronic throttle body borrowed from Fordís 6.8-liter V-10 truck engine program.
Beating the Heat
To manage heat produced by 500 horses, engineers devised a set of GT500 specific features, including an air-extractor hood, a high-capacity aluminum radiator, an intercooler mounted below the blower, a loop-style power-steering cooler and an oil-to-water stacked-dish engine oil cooler.
4-Valve Heads from Ford GT
While supercharging is a key element in the Shelby GT500ís ability to generate so much horsepower, another major contributing component is the design of cast-aluminum, four-valve cylinder heads sourced from the Ford GT supercar.
Machining changes are incorporated into the outside ends of the heads and to the left rear cam cap to fit the engine into the Mustang chassis.
Developed specifically for supercharged applications, these high-performance heads use high-flow ports and specially calibrated dual-overhead camshafts to deliver optimum engine "breathing" along with surprisingly good fuel efficiency and emissions.
The cams and valvetrain are specific to the Shelby GT500. The cam drive system is unique and designed to fit into the Mustang engine compartment, which is narrower than the Ford GTís. The oil pan and windage tray are the wet-sump setup from the Mustang GT. The Ford GT uses a dry-sump arrangement.
Powered by SVT
To enthusiasts, the real beauty of any performance car rests with its engine. That idea certainly wasnít lost on Carroll Shelby because Mustangs that bore his name have traditionally brought his unique sense of style and personality directly into the engine compartment. One Shelby signature feature Ė special finned-valve covers embossed with "COBRA Powered By Ford" Ė soon became the envy of so many Ford V-8 owners.
The GT500 is equipped with special "Powered by SVT" finned-cam covers to hint at the beauty of all those horses lurking in the engine below. Mated to the Ford GT 4-valve cylinder heads are unique exhaust manifolds that help to better scavenge spent gases out of the cylinders and into the custom-tuned mufflers and dual-exhaust system.
And the aggressive exhaust note, which is unobtrusive in everyday driving situations, was truly custom tuned.
"More than 40 different muffler tunings were tested, measured and evaluated to come up with the right sound," says William Woebkenberg, an engineer with SVT.
A special device called a "tuned exhaust crossover" was incorporated to create the special sound. Unlike the H-pipe design used by the Mustang GT, the Shelby GT500 uses an X-shape stamping to create the desired sound and increase power output through dynamic scavenging.
The gearbox used by the 2007 Shelby GT500 also is a rarity. Few transmissions exist in the marketplace today that can handle the torque loads generated by the supercharged GT500, so engineers are opting to stick with the proven heavy-duty performance of the TR6060 6-speed manual gearbox.
The GT500 employs an upgraded version of the T-56, which first appeared in the 2000 SVT Mustang Cobra R, powered by a naturally aspirated 5.4-liter V-8 with 385 horsepower, and later in the supercharged 2003 SVT Mustang Cobra whose DOHC 4.6-liter produced 390 horses. For the Shelby GT500, the six-speed manual will be geared to make the most of the supercharged 5.4-literís broad power band.
"One of SVTís goals in creating a vehicle is to deliver a balance of performance Ė acceleration, cornering, braking," says director Thai-Tang.
Another goal is to develop products and processes that can be applied not just to high-performance products, but also to other vehicles and in other parts of the company.
Then and Now
Performance cars have evolved dramatically since their heyday in the 1960s. In terms of safety, efficiency and refinement, todayís street machines totally outperform their elder muscle car colleagues in nearly all categories. Yet the story is seldom told about the tremendous gains made in reducing emissions while increasing overall power output.
The fact is, the GT500 is easily twice as powerful as the hottest V-8 package offered when Mustang was first introduced Ė yet still produces from 100 to 300 times fewer emissions. Additionally, todayís modern "MOD" V-8 powertrain enjoys a nearly 60-percent increase in average fuel economy compared to corresponding Ford products produced 30 years ago.
Back in the so-called Muscle Car era, driving a street beast with more than 400 horsepower was a dicey proposition. When dual carburetors, progressive linkage and dual-point ignitions were part of the equation, performance came with a price Ė drivability. Running too lean or too rich Ė or with the timing or spark out of adjustment could mean it would misfire or "carbon up" Ė sometimes with thick, black smoke coming from the tailpipe. Worse yet was fuel economy, with most of the big, high-powered V-8s at the time netting anywhere from six to 10 miles per gallon in typical driving.
Fordís "MOD" V-8 family of engines makes more power than any Ford motors of the past, yet tops 20 mpg on the highway and meet the governmentís LEV-II tailpipe emissions standards.
Multi-valve Engine Technology
Modern, race-derived technology provides an interesting power comparison: The GT500 with a 5.4-liter, DOHC, supercharged V-8 produces better than 100 horsepower more with nearly 100 fewer cubic inches. Compare that with the 1967 Shelby GT500ís 355-horsepower, 428-cubic-inch-displacement, big-block V-8.
The GT500 uses cylinder heads with four valves per cylinder and double overhead cams for optimum engine "breathing." Using multiple valves per cylinder provides the engine with a more efficient airflow, generating higher peak horsepower. As an additional benefit, multi-valve engines better utilize the air-and-fuel mixture in the cylinders with less waste and unburned fuel vapor. Also, multi-valve engines are better suited to help scavenge exhaust gases out of the cylinder after combustion is complete for more power with cleaner tailpipe emissions.
In addition, supercharging produces the peak horsepower of a much larger-displacement, naturally aspirated engine. Yet, at lower throttle applications, the smaller displacement enabled by supercharging consumes less fuel, resulting in increased fuel economy and lower emissions.
As a result, the 2007 Shelby GT500 is designed not only to be the most powerful Mustang from the factory Ė but also one of the cleanest.
The 2007 Ford Shelby GT500 is a purposeful performance car and striking to look at.
The design team did not merely take heritage cues and paste them onto the contemporary Mustang. Working with the engineering team, they dedicated themselves to a design that would enhance the carís performance.
For example, the fog lamps were removed from the upper grille opening Ė where they are located on the Mustang GT. Smaller units were relocated on the outside of the lower front fascia where they function well.
"We found that the original Shelby Mustangís design came about in response to maximizing the carís performance," says Doug Gaffka, chief designer for Mustang, SVT and Vehicle Personalization. "The same is true of the SVT design language that has evolved over time."
A further example of how form follows function is the design of the heat extractors on the hood of the Shelby GT500. Here, they can better remove heat from the engine compartment Ė an important consideration for a car generating 475 horsepower.
"It is perfect, says Carroll Shelby of the carís overall design. "I wouldnít change a thing. It is everything I expected a modern Shelby Mustang to be."
Other functional aero additions to the Shelby GT500 can be found at the front and rear. The rear spoiler adds significant downforce. Similarly, the front air splitter effectively combats lift.
The 18 x 9.5-inch wheels worn by the Shelby GT500 also bear a resemblance to those of the Ford GT.
The 2007 Ford Shelby GT500 boasts an upgraded version of the mainstream Mustangís interior, designed to cater to the dedicated driving enthusiast.
Most apparent is the use of light-faced gauges, a tradition on SVTís cars and trucks and one that can improve readability under a variety of lighting conditions. The gauges also boast SVT graphics.
An astute observer will note that the speedometer and tachometer do not occupy the same positions they do in the rest of the Mustang line. In the Shelby GT500, the speedometer is on the left while the tachometer is on the right.
"This is something the SVT engineering staff insisted on Ė particularly because the GT500 is available only with a manual transmission," says Keith Rogman, SVT design manager. "Making the switch allows the driver the best view of the tach while changing gears."
Shelby GT500 sports a satin aluminum finish on instrument trim, rings and door handles. This helps reduce glare and provide a bit of sparkle.
Adds Doug Gaffka, chief designer for Mustang, SVT and Vehicle Personalization: "This is very much in keeping with the SVT hallmark of substance. It gives the customer a direct benefit and not just a bit of decoration."
Sit Down and Drive
Substance and function also are the reason the front seats in the Shelby GT500 are different from other Mustangs. Bolstering has been added to provide increased lateral support. This helps keep the driver optimally placed.
Seating surfaces are leather, and the classic figure of a cobra is embossed on the front seat backs. A cobra is also prominently featured on the tilt steering wheelís air bag cover. The wheel rim is wrapped in leather and has unique thumb pads. The shift boot is also made of leather and the parking brake handle is leather clad.
Two interior color treatments are available, charcoal black and charcoal black with crimson red seat inserts and door trim panels. A GT500 Performance Interior Trim Package is optional. It features a leather-wrapped and stitched instrument panel brow and center console, upgraded door armrests and aluminum pedal covers.
Performance Sound System
SIRIUS Satellite Radio may be ordered with either the standard Shaker 500 Audio System or the optional Shaker 1000 system. The Shaker 1000 Audio System amps up to a full 1,000 watts from the standard systemís 500. It includes two subwoofers as part of its 10-speaker array, and an audio input jack is standard. Both the Shaker 1000 and the 8-speaker Shaker 500 systems include AM/FM Stereo with a six-disc in-dash CD changer with MP3 capability.
Comfort and convenience touches abound. Manual air conditioning, power windows and power locks are standard. The center console includes not just an armrest, but storage as well. The interior also features dual power points as well as two cupholders.
And the Ford Special Vehicle Team has put its stamp on things as it welcomes enthusiasts into the car via bright door sill trim plates bearing SVT script.