If you want to see some crazy excess, you'd head to Las Vegas, right? We'd say $80,000 for a Mustang is excessive. So, too, is 540 hp. Thus, it's only fitting that this particular Mustang is from Vegas. It may start its production process in Michigan as a "regular" GT500, but it's finished off at the Shelby factory in Sin City, where it becomes the King of the Road.
The new, extra-excess Shelby uses the 5.4-liter supercharged V-8 from the current GT500 but gains 40 hp and 30 lb-ft of torque through revised engine programming. The V-8 exhales through a new low-restriction exhaust that employs an H-pipe - in place of the GT500's X-pipe - to accentuate the V-8's burble; its lovely lope sounds like a big-bore boat engine at idle, and in normal driving, it sets off car alarms and sends pedestrians scurrying for cover. Boot the loud pedal, and the supercharger's psychotic whine conspires with the V-8's demonic wail to drown out even the loudest of police sirens. The regular GT500 sounds like a Toyota Prius by comparison.
The sound isn't the KR's only attention-grabbing characteristic - with its aptly named "over-the-top" Le Mans-style double racing stripes and the GT500's aggressive front-end treatment, no one will mistake the KR for a rental Mustang. Its hood is made of carbon fiber and features dual integral ducts: one to route fresh air into the engine, another to force hot air away from it. Two beautifully machined stainless-steel twist-to-lock fasteners keep the lightweight hood latched.
Ford's Special Vehicle Team (SVT) worked with Shelby to improve the GT500's handling without sacrificing ride quality. The KR's firm, but never harsh, ride is almost European in feel - retuned dampers are significantly stiffer in rebound, eliminating the acceleration squat and brake dive that makes the GT500 seem so softly sprung. Its polished-aluminum, eighteen-inch Alcoa wheels are shod with ultragrippy F1 Supercar tires that were developed jointly by Goodyear and SVT. According to Ford, the tires provide a nausea-inducing 1.0 g of sustained skid-pad grip.
The cabin is similar to those in other well-equipped Mustangs, so the KR's driver is treated to a leather-covered upper dash and a large, leather-wrapped steering wheel that's positioned a little too far away. The standard Shaker 500 stereo system should be called the Leg Shaker 500, because large woofers in the door vibrate the occupants' legs so violently that there might as well be a hormonal Jack Russell terrier hiding in the footwell.
The KR's ultrastiff clutch pedal controls a twin-plate, semimetallic clutch that hisses audibly on engagement - the perfect complement to all the snake emblems on and inside the car. The clutch plates are extragrabby, making shudder-free starts tricky, but once underway, the quick throttle response makes rev-matched shifts a cinch. A KR-exclusive short-shift kit reduces throws by 25 percent compared with the GT500's shifter, and it's refreshingly precise in its operation.
The 2008 GT500KR is the most powerful and quickest Mustang ever. With the help of a shorter final drive (3.73:1 versus the GT500's 3.31:1), it stomps to 60 mph in only 4.3 seconds and roars through the quarter mile in 12.3 seconds at 115 mph, according to Ford. The car gallops on to an electronically limited top speed of 155 mph. On the road, it has little trouble performing magnificent - if sometimes accidental - burnouts off the line. Its live rear axle will readily kick out the tail if it's irritated by a midcorner bump, but thankfully the rear steps out gently and in an easily controlled manner.
On the track, the GT500KR is definitely the king of production Mustangs. On the supersmooth pavement at Miller Motorsports Park near Salt Lake City, the big pony car turns in with authority and generates loads of grip through both low and high-speed corners. Body motions are exceptionally well-controlled, and the KR's brakes - four-piston Brembos up front, two-piston rears - survive lap after lap of hard use. Perhaps the most surprising trick up this steed's sleeve is how well it puts down the thrust of 540 horses. Traction is almost never an issue; full-throttle through smooth second-gear corners results in no excess wheel spin or snap oversteer. The Mustang is, of course, a fairly heavy car with a pronounced front weight bias, so the KR prefers a slow-in, fast-out approach that takes advantage of its massive midrange torque to explode out of corners.
The KR is likely the best Mustang on the road, too, and will certainly become a collector's piece. Like other Mustangs, however, it has fairly numb steering and an interior filled with inexpensive materials. It also lacks an independent rear suspension. An $80,000 price tag on a Mustang is hardly rational, but that won't stop Shelby's devoted fans from gobbling them up. Like all things related to Las Vegas, when you're talking about gross excess, silly little things like price never seem to matter.