Detroit Show: Shelby GT500 gets 403kW supercharged V8 muscle

FORD has raised the performance bar with its latest version of its supercharged and intercooled 5.4-litre V8 Shelby Mustang, which will be unveiled at the Detroit auto show next week.

Ford hopes that its new performance leader will “polish the Ford oval” and restore the company’s tarnished image in the wake of the US auto industry meltdown and government bailout.

“We need to uphold the Mustang badge with honor, the Shelby badge with honor and, most importantly, the Ford badge with honor,” said SVT engineer Jamal Hameedi. “The 2010 GT500 is the car that will do all of that.”

The blue oval’s hot car outfit, Special Vehicle Team, has installed the version of the engine developed for last year’s 40th anniversary edition Shelby GT500KR, which produces some 540 horsepower (403kW) and 510 foot-pounds (691Nm) of torque.

With a shorter 3.55:1 diff ratio to aid acceleration (but taller top gears in the six-speed manual to improve fuel consumption figures), the latest Shelby GT500 is claimed to accelerate from 0-100km/h in around 4.5 seconds.

Developed in conjunction with legendary Mustang figure Carroll Shelby, whose original Shelby Mustangs set new performance marks from 1965 to 1970, the latest Shelby GT500 is based on the new Mustang that was introduced at the Los Angeles show in November.

It is expected to go on sale in the northern spring (about April) and is the fourth in the line since being revived in 2006.

SVT says it used the “King of the Road” GT500KR as the performance starting point and made aerodynamic changes that have increased downforce and reduced drag.

It says that the open-element air induction system features a conical air filter instead of a flat-panel closed system to reduce air restriction, allowing more air to be pumped through the engine, producing more power and increasing the engine’s efficiency.

An improved cold-air intake necessitated moving the Cobra snake badge from the left to the right-hand side of the grille to enable maximum airflow.

The twin-disc clutch has been upgraded for durability and improved drivability, with bigger discs now made from copper and fiberglass.

First to fourth gears remain the same, but fifth gear changes from .80 to .74 while sixth gear goes from .63 to .50 to deliver improved highway fuel efficiency while the final drive goes from 3.31 to 3.55.

Firmer spring and damper rates have been specified to improve grip and handling, as well as give the GT500 a flatter cornering stance, and the coupe rides on 19-inch forged aluminium wheels while the convertible runs 18-inch alloys.

SVT says that the 19-inch wheels are milled on both sides and the extra machining process creates “blade” spokes with very thin, yet strong, cross-sections.

Mr Hameedi said the steering shaft was also stiffened as part of the overall attempt to make the GT500 more responsive, but easier to drive.

“All our changes were about making the car respond as fast and as predictable as possible,” said Mr Hameedi.

“It conveys an athletic, confident feel. The shifter, clutch pedal, brake-pedal efforts and overall steering efforts are easier now. We wanted to make sure we had a nice, crisp short-throw shifter that was easy to go from gear to gear.”

Although occupants in the new interior are protected from “unwanted noise” by improved NVH levels, the engineers have worked to ensure a satisfactory aural experience in the latest GT500.

“You still hear the supercharger but not so that it’s intrusive,” said SVT chief functional engineer Kerry Baldori. “It’s the same with the exhaust. You want people to know you’re driving something special, but you don’t want an exhaust note that overpowers the whole interior.

“We spent a lot of time getting the right sound quality out of the exhaust so you get that nice, crisp Shelby sound outside and a pleasant sound inside the cabin. It’s a nice balance one isn’t overpowering the other.”

Aerodynamic upgrades include a redesigned front splitter, a lower-drag rear spoiler and numerous detail refinements around the front of the car and the engine bay designed to reduce drag and seal components like the radiator and intercooler.

“We worked hard to get as much downforce with as little drag as possible,” said Mr Baldori. “We worked to seal off the air that comes in the front so it can’t go underneath the car.

“The result of this evolution of aerodynamics is we’ve increased downforce, reduced drag and improved the overall efficiency of the 2010 Shelby GT500.

“We chose a ‘flush’ hood where the fascia defines the entire front of the vehicle. That’s very hard to execute from an engineering standpoint, but it really sets the Shelby off as very, very different from the base Mustang.”