Steve Turner
Former Editor, 5.0 Mustang & Super Fords
October 1, 2008

With a new calibration, exhaust, and cold-air induction coupled with 3.73 gears out back, the KR accelerates quicker than a base GT500 and is capable of 1g acceleration on a skidpad. The springs are 17 percent stiffer up front and 7 percent stiffer in the rear, and the dampers and sway bars were tuned to work in concert. The results are impressive, as the car handles much better than the base GT500 but retains great ride quality. Now the base GT500 is capable of 0.92 g, so it's no slouch, but the KR takes it up a notch, which is far enough to require the use of an axle-vent reservoir developed for the FR500C to keep fluid from blowing out during prolonged, hard cornering.

There's nothing internally different about the GT500KR's engine versus the base GT500, but it's enhanced with a Ford Racing cold-air induction kit, a more aggressive exhaust system, and a crisper calibration that combine to make the car feel quicker and sharper. Increased ignition timing and improved electronic throttle response are the major contributors. Besides the CAI, billet caps for the radiator, intercooler, power steering fluid, windshield washer fluid, and oil-fill highlight the KR engine compartment. The tag on the core support denotes the true Shelby lineage of the KR.

While the main cold-air intake system is from Ford Racing, the version on the KR features bracing to reduce expansion and contraction from heat. A seal around the mass air housing and between the box and the hood keeps hot engine air out of the inlet. All told, the hood and cold-air intake are said to reduce the base GT500's 37-degree inlet temp increase over ambient by 5 degrees.

A work of art, the carbon-fiber KR hood is Ford's first use of carbon fiber in a production car. It's made up of more than 100 pieces of carbon fiber that are molded together in an autoclave to create a dual-zone pressure management system. Not only does it look great, but the scoops are functional, forcing ambient air into the airbox. Likewise, the rear vents function by letting pressure and heat out of the engine compartment while channeling water away from engine electronics. The hood, along with the exhaust system, contributes to a 22-pound reduction in curb weight versus the base GT500. The hood's outer panel is only 1.2 mm thick, while the inner panel measures only 0.8 mm and is 11 pounds lighter than the base car's aluminum hood.

Besides the way-cool 5.0&SF license plate, the centered Shelby lettering and V-6-style wing are sure signs you've approached a KR. The most telling sign, however, is the raspy rumble of the KR exhaust system which features an H-pipe instead of the X-shape crossover on the base GT500 along with the smaller, cylinder-shaped mufflers from the Bullitt Mustang. Since Shelby Automobiles is the manufacturer of record on the KR, the exhaust-noise standards were more flexible than those of a typical production-line Ford.

At first glance, there isn't much to distinguish the KR from the base GT500's interior other than the cue-ball shifter poking up through the center console. There's also a plaque on the dash and GT500KR stitching on the headrest. The shifter, however, contributes to the high-performance feel of the KR with shift throws that are 10.5 mm shorter than the factory version. The KR unit is actually a revised version of the Ford Racing shifter, which features slightly softer bushings to keep the noise, vibration, and harshness levels within factory specs.