View Full Version : Track Evaluation Magazine Article - Shleby Mustang Cobra GT500

Al C
08-07-2005, 08:18 PM
Track Evaluation – 2007 Ford Shelby Mustang Cobra GT500
Shelby Shakedown
Road & Track SPEED Magazine – Life at Full Throttle
July – August 2005

Muscle cars aren’t just for burnouts any more. Sure, back when Ford was spreading Mustang shock towers with 428 Cobra Jets, and Carroll Shelby was making them even faster, a GT-500 Shelby handled like a turbocharged bar of soap on the shower floor. But that was a couple of million smoked Poly Glass tires ago.

Now Carroll Shelby and Ford have reunited, kissed and made-up like the old couple they are. That relationship has resulted in the newest Mustang rendition, which is easily the tightest, best-handling Mustang ever. The car is called the Ford Shelby Cobra GT500, and unlike any other magazine in the world, at least for this week, we’ve driven it on the track.

Okay, we’ve driven the prototype. The 2007 GT500 won’t hit showrooms until mid-2007 and as we follow along, Special Vehicle Team engineers are still tweaking the shock tuning, selecting the final engine configurations and validating all the fun we will ever have with the GT500 before it is released for bad behavior.

The basics, though, are near final. Ford’s biggest-blocked modular V-8, the supercharged 5.4 –liter 4-cam from the Ford GT has been replicated with a vastly less expensive iron truck block, but retains the GT’s 4-valve cylinder heads, camming and bulletproof pistons, crank and rods. The prototype was supercharged with a Lysholm screw-type blower, but production GT500 engines will use Eaton-built Roots blowe4rs because Lysholm can’t whittle it’s compressors fast enough to meet the approximately 7000-unit production goal. Water-to-air intercooling is standard and the working power rating is 450-bhp-plus. We’re expecting a final figure of 465 bhp – or maybe more.

Teamed with a dual-disc, 215 mm clutch, Tremec’s latest T56 6-speed gearbox backs up the V-8 with triple synchros on first and second gears, wider gear teeth and reduced shift effort. The same 8.8 inch live axle as in the standard car was selected, but sporting taller 3.31:1 gears.

Though the MacPherson strut front and 3-link rear suspension remain, the spring, swaybar and shock tuning is optimized for the GT500’s tough street mission. New 285-section tires in the rear wheelwells are able to satisfy Ford’s fender-clearance tests. SVT selected Brembro 4-piston calipers to put the bite on the 14-inch front discs. Rear braking is standard Mustang with better pads.

We’ll let the pics of the show car tell the styling story, but yeah, it looks like a 19668 GT-500 Shelby minus the quarter window air scoops – raw and aggressive. The show car’s GT-like “split spoke” 19-inch billet wheels won’t see production. Instead, the new Shelby will prowl on 18-inch rolling stock, using Goodyear Eagle F1 Supercar tires originally developed for the GT. Aggressive compounding and tread mean these tires won’t last 40,000 miles, but they will survive hot-lapping at the local track.

SVT was putting in fast laps when it had us out to the Grattan, Michigan, road course. A devilishly convoluted and occasionally bumpy track, Grattan is a road tester’s paradise. “A mini-Nurburgring” is how Jay O’Connell, SVT’s chief engineer, summed it up. And with experience in every form of motorsports, including F1 and driving on the real Nurburgring, Jay should know.

Between laps, the engineers were swapping steering racks in the prototype, all in the name of obtaining the best steering feel – and we were starting to get excited. A muscle car on a road course? This should be fun.

And it was. Hammering out of the pits, the GT500 puts down the power through its live axle and goes. There’s enough power and gearing to spin the hides in first, but with the big rear tires and the more plush-than-harsh suspension, traction is good.

Clutch action is a bit long, but light for such power, while the shifter suffers from a rubbery feel that’s more a mental bother than a threat to gear selection. You can blame the new Mustang’s remote linkage while ordering your aftermarket shifter.

It took some laps to see what the engineers were looking for in the GT500’s steering. The steering works fine, but could use more personality, as it is slightly over boosted for track duty. SVT engineers will edge closer to that elusive combination of sports car feel and reasonable parking lot effort demand of a real world car.

The GT500’s handling is awesome. Turn-in was precise and the line around corners accurate and linear. With the new Mustang’s elongated wheelbase, the big engine’s heft is carried mainly between the axles, for minimal understeer. We found ourselves nit-picking our apexing and car placement, pleasantly surprised that the big Shelby would let us. This is real progress over even last year’s Mustang Cobra, much less a ’68 GT-500.

But like the original GT-500, the new Shelby is one big boy. Less tank-like than its immediate SVT Mustang Cobra predecessor, the Shelby still feels like a couple of tons. And it is. Add a large driver, and the Shelby’s fighting trim is 4100 lb. It’s a wonderfully balanced and grippy bulk, but it’s bulk enough to keep from calling this Shelby a sports car. Hammered over high speed bumps, it shakes like a wet dog as the nicely-riding, street-tuned springs and shocks begin to lose control of the forces in motion.

Dearborn’s answer to this is the same as it’s always been: more power. Even cautioned the prototype was a bit lazy during our visit, there was real steam under the GT500’s vented hood. Hit it and the delicious scream of tortured air whines from the supercharger, the V-8 burble turns to a roar, the rear end squats and you’re outta there. The 330 cubic inch displacement give a strong power hit – even if jaded straightline fans will add more rear gear before claiming total satisfaction - and the fun runs smoothly from tach bottom to tack top. SVT is the master of rheostat powerbands with real thrust, and the blown 5.4 is another Ford tour de force.

More than just a dragstrip necessity, the smooth power was key to balancing the Shelby around Grattan’s challenging off-camber turns. If only every car responded so easily and accurately to throttle inputs.

Finally, there is the question of what the Shelby is where the SVT Cobra went. The Shelby GT500 is the new Mustang Cobra with Carroll’s aesthetic sensibility and name added to it. With both SVT and Shelby script appearing on the car, there’s no permanent shift taking place, and SVT is not going away. With an estimated price of $38,500 and a supreme combination of power and handling, we’d say it’s only getting stronger.

08-08-2005, 11:36 AM
I want one :(

Thanks for posting the article Al :thumbsup: