Wild horses

By DAN NEIL

Dec. 27, 2006 12 AM PT

BEFORE I begin, let me just say to all you hard-core Mustang enthusiasts: The sun will come out tomorrow. Your mullet will again dance in the wind and Bon Jovi will still be the most awesome band from central New Jersey. Be not dismayed that I’m going to talk smack about the insanely coveted 2007 Ford Shelby GT500, because yea verily, I’m gonna.

This more-or-less rudderless rocket ship -- with a 500-hp supercharged V8 under the air-extractor hood -- is the most powerful production Mustang ever and one of the creepiest handling modern muscle cars it’s ever been my terrifying pleasure to drive: under-sprung, over-tired, nose-heavy in a way that would put Adrien Brody to shame. The live rear axle has more trampiness than a week at the Spearmint Rhino. The chassis has more windup than pitcher Daisuke Matsuzaka.

True story: So I’m juking along in the blue-striped pony on an empty freeway onramp at a, well, spirited pace, if your spirit is a Category III hurricane. Right-side suspension is squeezed down nicely, steady throttle, Thor is in his Heaven and all’s right with the world. Then the car crosses an expansion joint and the rear end is instantly teleported one foot to the right. Whoa! Did I just swallow my cellphone?

Oh, Mustang, you are so heading for the Purina factory!

Careful readers may think they espy a certain lack of reverence for the Ford Mustang. But it just isn’t so. I shudder to think what I’d do for a 1968 Shelby Mustang GT500KR. This is the place where one gives due props to, first, Lee Iacocca, the executive at Ford who green-lighted the Mustang for 1964, a car that went on to become one of the most successful fun-mobiles in history and an automotive icon.

Props, too, to dear old Carroll Shelby, erstwhile chicken farmer and Le Mans racing legend, who in the mid-’60s persuaded Ford to stuff monster motors into stripped-out Mustangs to go racing in SCCA B Production and Trans Am, where they beat the pantaloons off Corvettes. While the rest of the world was enjoying the Rage of Aquarius, Shelby and his band of duck-tailed and mutton-chopped minions where building some of the most charismatic street cars ever at their facility at LAX. The best of these was the 1967 Shelby Mustang GT500, with a 428-cubic-inch big block.

This car was da bomb. Speaking of bombs, a GT500 named “Eleanor” starred in the Nicolas Cage movie “Gone in Sixty Seconds.”

Fast-forward 40 years, when Ford sales are, generally speaking, set on rewind. The S197-chassis Mustang -- which debuted in 2004 as a styling clone of the late-’60s fastback pony cars’ -- is one of the company’s bona fide hits. And not without reason: The car looks badass, brooding, hunched over and malevolent, like it was contemplating the first punch of a bar brawl. Just about perfect.

The only trouble is the Mustang GT -- powered by a 4.6-liter, 300-hp V8 -- doesn’t exactly set the world’s timing towers on fire. From the drive-thru window to 60 mph takes in the low-5 second range in the Mustang GT, which while seriously quick puts it at a disadvantage against wasabi-flavored imports like the Subaru WRX STi.

As for the base model, the 210-hp V6 Mustang, please. Looks like Tarzan, punches like Jane.

Mustang fanatics, opiated with Shelby heritage, have clamored for a hotter horse, and the company’s Special Vehicle Team (SVT) is happy to oblige.

And thus was reborn the Shelby GT500, a modern Mustang with what is, in effect, a supercharged truck engine. Under the bulging air-extractor hood is Ford’s modular iron-block Triton 5.4-liter V8, coiffured with the aluminum heads from the Ford GT supercar and snorting a maximum of 8.5 psi of atmosphere through an inter-cooled Roots-type supercharger. Keeping this hand-assembled engine, well, assembled, is a forged-steel crank, forged aluminum pistons and various other reinforcements and cooling systems to manage the heat and 480 pound-feet of twist at 4,500 rpm. (For reference, the 1968 Shelby Mustang GT500 had a 7.0-liter V8 that could only manage 360 hp and 420 foot-pounds at 3,200 rpm.)

The apportioning of gear ratios falls to a Tremec six-speed manual gearbox, aft of which is the Mustang’s beef-tastic live rear axle. The Mustang is the only current major-manufacturer sports car I can think of with a live axle (am I forgetting a car, readers?). It’s worth noting that the previous generation SVT Mustang Cobra had an independent rear suspension, but Ford wasn’t quite so cash-strapped then.

And so the fun begins.

A quick primer on automotive suspensions: A live axle is essentially a solid link that connects the rear wheels, so that what affects one wheel, like a bump or pothole, conversely affects the other -- one wheel goes up, the other tries to go down. Live axles are good because they can handle lots of torque; they are also cheap and compact. They are bad in pretty much every other way, primarily because neither wheel is independent of the other. Also, because of the geometry, a live axle is basically unsprung weight, which means you need to screw down the suspension to control its bobbling, undamped mass.

But, of course, there was only so much screwing down the chassis guys could do. For a couple of reasons. First, because Ford is going to sell these cars to civilians, not racers. And the suspension settings (spring rates, shock damping, wheel travel) necessary to keep the axle located would make the ride unspeakably stiff for any organism in possession of a spine.

Reason No. 2: Weight transfer. Because of the iron-block anchor in the nose -- accounting in large part for the 564 pounds the GT500 weighs over the Mustang GT -- the car’s suspension has to be pliant enough to allow the car to sit down on its back wheels on acceleration (weight balance is 57/43, front/rear). Without this, the GT500 would wind up frantically smoking its 285/40ZR18 rear tires, which is great if you’re fumigating for dengue fever but bad if you’re trying to lay down a hot ET. In other words, you need weight transfer for a better holeshot.

The chassis guys did what they could: The front MacPherson struts have firmer spring and damping abetted by the standard 24-mm anti-roll bar; the rear suspension (three-link live axle with stiffer coils, outboard springs, Panhard rod, and a larger, 34-mm anti-roll bar) has likewise been upgraded to account for weight and balance. There’s an added cross brace between the rear lower arm bushings. On smooth pavement, the GT500 has significant steady-state cornering grip. Breathe off the throttle, and the forward weight transfer gives the car a touch more front bite. Steering is light and true.

But in my flog across Kern County -- the only place in America where you can get a dust-flavored latte -- the GT500 rolled, bounded, skipped, over-rotated and axle-hopped in every place where there wasn’t perfect pavement, which was, um, just about everywhere.

If you’ll forgive me, it was like having sex on a waterbed: It felt really good but highly unstable.

The GT500 is respectably quick, to be sure. I managed some clutch-dropping passes in the 4.5-second range; just as often, however, the wheel-tramp got to be so bad I had to let off the throttle. It’s easily a 13-second car in the quarter-mile if this wild horse doesn’t champ through the bit.

But for all it’s pro-mod credentials, what this car delivers best is not track-day pyrotechnics but huge, billowy gusts of super-smooth acceleration in the passing lane. The Tremec TR6060 gearbox is just about perfect, with the machined precision of a pair of Fiskar scissors. The exhaust is a polyphony of snotty, guttural dual exhaust and the industrial vacuum whine of the blower.

There are lots of reasons to love this car: the 14-inch front mega-brakes by Brembo, for instance. If looks could kill this thing would be in the dock at The Hague. With the optional fog lights relocated to the lower front fascia, the black-diamond grilles have been opened up and made scarier and more appetitive, a hungry maw. The front splitter and rear wing provide some aero stability at high speed, though the faux diffuser on the back is a little silly. With a Shelby Cobra emblem on the grille, the side, the headrests, the steering wheel and the gas cap, this thing’s got more snakes than Samuel L. Jackson’s plane.

Great handling? No, but after all, that’s not what you, Mr. Mustang fanatic, are all about. You’re a cowboy. On a steel horse you ride.

dan.neil@latimes.com

(BEGIN TEXT OF INFOBOX)

Base price: $40,930

Price, as tested: $43,500

Powertrain: 5.4-liter, DOHC, 32-valve V8, with Roots-type supercharger (8.5 psi max boost); six-speed manual transmission; rear wheel drive

Horsepower: 500 at 6,000 rpm

Torque: 480 pound-feet at 4,500 rpm

Curb weight: 3,920 pounds

0-60 mph: 4.5 seconds

Wheelbase: 107.1 inches

Overall length: 188 inches