Apparently, father Ford knows best when it comes to Mustang performance, because the best efforts of any aftermarket tuner would not equal the FR500. The "homegrown" Ford Racing Performance FR500 is what the mass-produced Mustang was meant to be - if it didn't have to fit tamer buyers, too.

Ford Racing Technology engineers set out to build FR500 as a parts showcase for Mustang Cobra owners who want true bolt-on performance for their 4.6L DOHC V-8s. Dan Davis, director of Ford Racing Technology, says three goals dominated this project: 50/50 front/rear weight distribution, a minimum of 400 hp, and not a pound added to the stock Cobra's weight - 3, 450 lbs. (1,565 kg). As an aside, all the hop-up parts had to bolt on with simple tools.

The FR500's modifications are extensive, but the highlight is the extended wheelbase. Using a refabricated front support structure, Ford engineers pushed the front suspension forward 5 ins. (12.7 cm) to give the FR500 a better footing and to help achieve that 50/50 weight distribution - the holy grail of handling. The stretched Mustang looks and feels more like a nimble European sports sedan than an American muscle car.

But make no mistake, the muscle is there. At 6,800 rpm the FR500 develops a hefty 415 hp and keeps pulling until the 7,000 rpm redline. The torque, 365 lb.-ft. (495 Nm) at 4,200 rpm, is sufficient to paint the pavement black just about any time you please.

If this is Ford's interpretation of what the Mustang is supposed to be, why don't the Dearborners simply build the FR500 on the assembly line?

Mr. Davis cites several reasons. First, the car would require costly crash and emissions certification.

And then there's the matter of "streetability" typically lacking in aftermarket "tuner" cars: That means a decent ride and sound levels that won't leave the spouse refusing to take a road trip.

"Ford isn't going to do a car (that isn't reasonably refined)," insists Mr. Davis.

And never mind price: "If this is a $100,000 car (in production), forget it." He admits, however, that Ford "really hasn't studied the cost implication of mass production," but is pondering the idea.

Prices for the components for you to make your own FR500, says Ford, have yet to be determined.