Ford Shelby GT500KR : The most powerful Mustang

With Texas-seized fanfare, complete with fireworks and a chili cook-off, Carrol finished his 85th lap of the sun this past March.

For, on the same day he clicked off 85 years, the first example of the latest and perhaps the greatest car to bear his name, the 2008 Shelby GT500KR (as in “King of the Road“), rolled out of the company’s Las Vegas shop. This new KR, which is essentially a 2008 Shelby GT500 Mustang turned up to eleven, was created to celebrate the 40th Anniversary of the original King of the Road, a hotted -up version of the already plenty hot 1968 Shelby GT500.

Chatting with Mustang architect Lee Laccoca one day in 1967, ol’ Shel got the wind of plans within Chevrolet to announce a King of the Road version of the Corvette in a scant 2 weeks. The car debuted in April of 1968 with 428ci Cobra Jet V-8 engine, very conservatively rated at 335hp and 440 pf of torque. Before they were done, Shelby and Ford had unleashed 1571 GT500KR Mustangs on an unsuspecting America; 1053 fastback coupes and 518 convertibles. The new KR is a coupe-only model, and among the modern-era Mustangs, it perhaps best recalls the dizzyingly fast Cobra R from 8 yrs ago. Like the Cobra R, the GT500KR as first seems almost too savage and single minded for its own good, monumentally powerful and possessed of preternatural racetrack reflexes.

But the King is vastly more civilized, offering a surprisingly tame Highway ride and amenities the Cobra R never did, including AC, a stereo, and a back seat. You can even specify a DVD-based navigation system and a Sirius Satellite Radio.

The sprawling facility, now home to the Ford Racing High performance Driving School, is the grand undertaking of Utah businessman, Larry Miller, who, in addition to owning more than 40 car dealerships and the Utah Jazz basketball team, happens to be a Shelby and Ford fanatic. Among the inestimably valuable cars in his tidy museum is the very first production Shelby Cobra (CSX2002) and the 1966 Le Mans-winning GT40. There is very little about the Shelby GT500KR that can be described as restrained. To their credit, however, SVT and Shelby exercised a remarkably light touch in the appearance department. Everything that looks different here is different for a purpose.

The KR is a bit more hunkered down than the GT500; it is lower by 20mm up front and 15mm at the rear. A broad carbon fiber front splitter increases downforce over the front wheels by a significant 31% while reducing drag by 3%, and a revised rear spoiler (more petite than the GT500’s) helps cut the car’s drag coefficient from 0.384 to 0.372.

Otherwise, there are the expected stripes and rocker-panel graphics, a handful of the 40^th anniversary badges, embroidered head-rests we could do without, a numbered plaque on the dashboard and the hood – a scooped and vented tumescent sculpture in carbon fiber. The suspension is fundamentals unchanged from the rest of the Mustang range – struts up front and a solid axle at the rear – but SVT has revised every aspect of its tune for KR service. During discussions with engineers from SVT and Shelby regarding KR’s handling, the conversation turned to that live axle. “Surely there is a better solution than a big hunk of iron b/w the rear wheels,” say journalists.

“Surely a sophisticated independent rear suspension would better befit a vehicle of the King’s stature and price tag.”

With a burly iron block and aluminium 4-valve heads, the KR’s suprcharges and intercooled 5.4l V-8 is an impressive sight, filling the Mustang’s engine bay like Ray Lewis fills a bathtub. The engine barks to life with 540hp and 510 pound-feet of torque, which is 40 horses and 30 pound-feet more than the standard GT500. Don’t be deceived by this relatively modest bump in output, however. The difference in character b/w the two cars is dramatic – every bit is pronounced as the differences b/w the base Mustang and the GT, and b/w the GT and the GT500. Aerodynamics and underhood air management figured prominently in the KR’s development, motivated by the expectation that more than a few KR owners actually know their way around a racetrack.

Far more than just a style statement, the car’s visually defining twin-nostril carbon fiber composite hood is a terrifically clever piece of kit and a masterfully engineered tool for managing the flow of air.

Technical Specification:

Bodywork
Type	2+2 Fixed-head coupe
No. of Doors	2
Dimensions & Weight
Wheelbase	2720 mm	107.1 in
Track – Front	1572 mm	61.9 in
Track – Rear	1588 mm	62.5 in
Length	4775 mm	188 in
Width	1877 mm	73.9 in
Height	1365 mm	53.7 in
Wheelbase Ratio	1.76
Ground Clearance	120 mm	4.7 in
Kerb weight	1771 kg	3904 lb
Weight Distr. (front)	58%
Fuel capacity	60.6 l	13.3 UK Gal
Engine
Bore x Stroke	90.22 mm x 105.80 mm	3.55 in x 4.17 in
Cylinders	V-8 in 90 deg Vee
Displacement	5409 cc
Type	Double Overhead camshaft	4 valves per cylinder Total 32 valves
Construction	Aluminum head	Cast Iron Block
Sump	Wet sumped
Compression ratio	8.40:1
Fuel System	EFI
Maximum Power	547.5 PS @ 6250 rpm	540.0 bhp (402.7 kW)
Specific Output	99.8 bhp/l	1.64 bhp/cu in
Maximum torque (SAE net)	692.0 Nm @ 4500 rpm	510 ft-lb (70.6kgm)
Coolant	Water
Bore/Stroke ratio	0.85
Unitary Capacity	676.13 cc/cylinder
Aspiration	S/charged
Compressor Type	1 Roots-type supercharger
Intercooler	Air-water
Catalytic Converter	Y
Chassis
Engine Location	Front
Engine Alignment	Longitudinal
Drive	Rear Wheel Drive
Steering	Rack & Pinion PAS
Wheels – Front	9.5 x 18
Wheels – rear	9.5 x 18
Tyres – Front	P255/45 Z-18
Tyres – Rear	P285/40 ZR-18
Brakes – Front	356 mm
Brakes – Rear	300 mm
Top Gear Ratio	0.63
Final Drive Ratio	3.73