Ford preparing fastest ever four-door—in Australia

Ford's struggling Australian outpost is set to unleash its fastest-accelerating car yet in the form of a limited- edition version of the four-door Falcon GT Boss 335 sedan running various chassis-based performance enhancements, according to Australian media reports.

Known internally at the company's Ford Performance Vehicles division under the code name Panther, the Blue Oval's supersedan is set to run the same supercharged 5.0-liter V8 as the standard Falcon GT Boss 335—itself a locally developed version of the Mustang's 90-degree Coyote unit with unique cylinder heads and renamed Miami. It delivers 449 hp at 5,750 rpm and 420 lb-ft of torque at 2,200 rpm.

Power is channeled through a six-speed Tremec gearbox, the same unit used by the Mustang GT500, to the rear wheels via a 3.73:1 final drive ratio. Buyers are also likely to be able to specify the new car with a six-speed automatic gearbox from ZF running a 2.73:1 drive ratio.

In standard six-speed manual guise the 3,759-pound Falcon GT Boss 335 sprints to 62 mph in 4.7 seconds and reaches a top speed limited to 155 mph—placing it in the same performance league as the more celebrated Audi RS6, BMW M5 and Mercedes-Benz E63 AMG sedans.

However, a 19-inch-wheel package and wider tires and subtle changes to the tuning of the suspension and stability control systems are said to improve traction off the line, allowing the Panther to outpace Ford's fastest four-door to date in the run from 0 to 62 mph, according to a report by the Sydney Morning Herald, which cites Ford's in-house acceleration testing.

No official quarter-mile times for the Falcon GT Boss 335 are quoted by Ford Australia. But in independent tests it has dipped below the 13-second mark. Rumors are that the Panther—apparently not the name it will take into production—will be even faster.

The fastest Falcon is likely to get its first public airing at the Sydney auto show in October, with Australian sales through Ford Performance Vehicles—a Melbourne-based outfit that is 51 percent owned by British engineering specialist Prodrive—before the end of the year.

By Greg Kable