Outrageous. Over-the-top. Completely ludicrous. Believe it or not, such descriptions of the Shelby GT500 convertible aren't hyperbole. Thoroughly updated for the latest model year along with its coupe sibling, the GT500 convertible packs a 662-horsepower wallop and is the most powerful production drop-top available in the U.S. besides the Bugatti Veyron 16.4 Grand Sport Vitesse (which costs $2.5 million).
At the center of the insanity is a new supercharged 5.8-liter V8 - which was initially expected to put out 650 ponies and 600 lb-ft of totque. However, the SAE has certified the engine at 662 horsepower and 631 lb-ft of torque, officially making it the world's most powerful production V8. An impressive 395 lb-ft are available just off idle at 1,000rpm, making the GT500 convertible an ideal burnout machine, and more 90 percent of the car's torque is available in the 2,200 to 5,800 rpm range.
To achieve such impressive power, Ford ditched the 5.4-liter V8 that has powered the range-topping Mustang for years, opting instead for an all-aluminum 5.8-liter V8. The SVT folks then added a new TVS series 2300 (2.3-liter) supercharger that provides 14.0 psi of maximum boost and a significantly upgraded cooling system that features a larger cooling fan, fan shroud with high-speed pressure-relief doors, an updated and more efficient air cooler, a higher-flow intercooler pump and a 36 percent bump to the intercooler heat exchanger's capacity.
Packing all of that muscle into the Shelby's updated body results in a top speed of 202 mph for the coupe, but Ford limits the convertible to 155 mph to prevent damage to the convertible top. The benchmark zero-to-60 mph sprint takes just 3.5 seconds, while the quarter-mile flies by in 11.8 seconds.
Don't think that the new V8 is a one-trick pony - rated at a respectable 15 mpg in the city and 24 mpg on the highway, it manages to avoid the gas-guzzler tax and is the most efficient engine with over 550 horsepower in America.
Unlike some its competitors, the GT500 Convertible isn't offered with an automatic gearbox. Shifting duties are handled exclusively by a tradition six-speed manual transmission, which features increased torque and rpm capacity thanks to its dual-disc clutch design.
How does the GT500 Convertible manage its traction problem?
Of course, when dealing with over 600 horsepower, traction management becomes a serious concern, and Ford has dealt with the situation by adding more than just new gearing. A new, defeatable launch control system has been developed that allows drivers high levels of control, permitting specific rpm launch points to be chosen based on elevation, tire and street temperature and other variables. This system is fully unique to the SVT lineup and is incorporated into both the engine control and traction control systems.
There is also a Torsen limited-slip differential that comes with the optional Performance Package, something Ford says helps even further to deliver maximum power output to the ground. Rounding out the driving dynamic upgrades are tweaks to the AdvanceTrac system, which now features appropriately adjusted steering assist levels based on the changes to the car.
To bring this nearly two-ton beast to a stop, Ford installed a new Brembo brake system that utilizes new six-piston calipers in the front, along with larger front and rear rotors. Ford says it also developed new brake pads that perform better under high-speed heavy deceleration.
Also part of the stopping equation are wheels and tires, to which the latest Shelby GT500 offers two new sets of forged-aluminum wheels including a unique wheel for cars with the optional packages. The 19-inch front and 20-inch rear wheels are coupled with Goodyear Eagle F1 SuperCar G: 2 tires on all vehicle configurations.
As with the rest of the Mustang lineup the GT500 Convertible gains updated headlights for the latest model year along with LED taillights, a blacked-out license-plate surround and body-colored rocker panel extensions. Unique the GT500 are quad exhaust pipes and two new wheel designs.
Standard and Optional Features
The GT500 Convertible is fitted as standard with leather upholstery, a leather-wrapped steering wheel with Alcantara trim, brushed aluminum interior trim, a 500-watt Shaker audio system with SiriusXM satellite radio and an AUX input jack, HID headlights and LED foglights.
The available Performance Packaged adds a Torsen limited-slip differential, unique forged-aluminum wheels that measure 19-inches in front and 20-inches at the rear, Bilstein adjustable dampers, unique rear springs and a special instrument cluster and shift knob.
Other options include a navigation system, recaro seats, heated seats and a 1,000-watt stereo system. An Electronics Package bundles the nav system with HD radio and dual-zone automatic climate control.
The GT500 Convertible features dual front and side airbags in addition to traction and stability control systems and a tire pressure monitoring system.
The Shelby GT500 is powerful enough to be mentioned in the same breath as the Chevrolet Corvette Convertible, the BMW M3 Convertible and the Porsche 911 Carrera Convertible, though all of those cars are more handling-focused that the somewhat muscle car-like Ford.