Hard to believe, but Ford now sells a 662-bhp Mustang. That's right, the new 2013 Shelby GT500 boasts six hundred and sixty two horsepower. Wow. That's more power than the Corvette ZR1. Ford, in fact, says this supercharged new 5.8-liter V-8 is the most powerful engine ever in a North American production car.
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No argument here. With 662 bhp on tap at 6250 rpm and 631 lb.-ft. of torque arriving at 4000 rpm, this new aluminum-block powerplant truly is a beast, giving the GT500 a top speed of 202 mph—reached in 5th gear during testing at the Nardo track in Italy. And while it may be tempting to call this new a front-heavy straight-line rocket, Ford's SVT crew has improved the car in several areas to create a well-balanced GT that's totally at home on a road course yet remarkably civil in everyday situations.
Big, Big Power
The heart of the new 2013 Shelby GT500 is its dohc 5.8-liter V-8, which has the same stroke as the previous 5.4 but has had its bore increased from 90.5 to 93.5 mm. This 32-valve V-8, with block cast by Hansel in Germany, is built to produce (and handle) all that new power, with forged crank, pistons and rods, camshafts similar to those used in the supercar, increased fuel injector flow, improved head gaskets and robust Stellite-faced exhaust valves that withstand the added cylinder pressure. Of note, the redline remains at 6250 rpm, but an over-rev function to 7000 rpm is allowed for up to eight seconds, in part to help prevent the GT500 from hitting its rev limiter during shifts in acceleration runs so 0-60 mph and quarter-mile times can be faster.
Other vitals: The compression ratio has been bumped from 8.4 to 9.0:1, and peak boost—provided by a new 2.3-liter Roots-type TVS blower with a 33 percent larger inlet and a 69-mm pulley (down from 72)—has risen from 9 psi to 14. The previous 5.4 had cast-iron cylinder liners, whereas the 5.8-liter V-8—a true 351 cubic inch V-8—employs plasma-transferred wire arc cylinder liner technology. This super thin (150 microns) spray-on bore surface saves about 1 lb. per cylinder while having the added benefit of reduced friction, less heat transfer and improved durability.
With further regard to durability, the 6-speed manual transmission, the only gearbox available with the GT500, has been considerably strengthened. The helix angle of the gears has been changed for more torque capacity, and both the case and the internal bearings have been strengthened. The new clutch, a dual-disc unit from ZF, has a significantly stronger springs, increased clamping load and higher performance friction material.
Another key piece of the 2013 Shelby GT500's driveline is the new driveshaft, a single carbon-fiber piece that has 36 percent more torque capacity yet weighs 14.4 lb. less than the steel 2-piece unit used previously. SVT engineers praise the stiffness of this piece, and add that its perfect balance is very much appreciated in a car with a 202-mph top speed. And it must be stated that one of the reasons this GT500 has such a high top speed is its high 3.31:1 final-drive gearing, which is made possible by all that torque. This also has the added benefit of improving the car's EPA mileage from 15 mpg city/23 mpg highway to 15/24. No need to pay a gas-guzzler tax here, a fact that was also true in the previous GT500, a car that was electronically limited to 155 mph.
Heat, Heat, Go Away
Heat soak is always a concern with supercharged high-performance engines, and SVT has gone to great lengths to make sure it's not an issue with the 2013 Shelby GT500. The intercooler's heat exchanger, mounted in the nose of this Mustang, is thicker, taller and wider than the previous unit, some 36 percent larger than the last GT500's, and it works with a more efficient charge air cooler mounted below the blower. Moreover, the pistons are now cooled by oil squirters, and there's nothing in the grille area that might even begin to impeded airflow into the nose of the car. The cooling fans now have six blades versus five, and they're driven by more powerful motors. Moreover, the fan shrouds have special ports that open at speed to allow more air across the all-important radiator. Lastly, the oil capacity and coolant capacity have both been increased.
If you plan to have some road course fun with your new 2013 Shelby GT500, order your car with the $2995 Track Package. This fits the base GT500 ($54,995) with an external engine oil cooler, coolers for the differential and transmission. Although this adds some weight to the car (SVT won't specify how much), the Track Package provides good piece of mind to anybody who will be seriously hard on their car.
Every buyer of the new 2013 Shelby GT500, however, should order the $3495 Performance Package. This includes a Torsen limited-slip diff, sportier springs, larger anti-roll bars and, most important, cockpit-selectable Bilstein dampers with Normal and Sport settings.
In what is likely a direct response to the Chevy Camaro ZL1 and its superb magnetorheological suspension, these monotube shock absorbers transform the GT500, making it civil in everyday situations yet sporty on the track. There's a big difference in ride quality between the two settings, and although the ride is very comfortable in Normal, the damping remains excellent and the car is still quite fun on a twisty road. In Sport, which is essentially a setting for the track, the ride is a bit harsh, but it's a small price to pay for the composure it gives the car on a fast and unforgiving track like Road Atlanta. For the record, the GT500 was tuned all around the world, at the Nürburgring, Grattan in Michigan, VIR and even a couple of endurance tests at bumpy Sebring, where Carroll Shelby was able to sample the car (and even spin it out a couple of times!) late last year before falling ill.
In short, the new Bilsteins work wonders for the GT500, aided by sticky Goodyear Eagle Supercar G:2 tires that have been built specifically for this car. The 265/40ZR-19 front tires have been tuned for maximum lateral grip, to help the car change direction, whereas the 285/35ZR-20 rears (the max width that will fit) emphasize excellent forward bite. The break-away characteristics under power are quite smooth and controllable, as long as the driver is reasonably judicious with the throttle.
Huge Brembos, with 15.0-in. front rotors clamped by 6-piston calipers, are always at the ready, aided by 13.8-in vented rears and a new Super Dot 4 brake fluid with a higher boiling point.
On the Road Atlanta track, the 3852-lb. GT500, which has 56 percent of its weight on its front wheels, bends into corners with surprising aplomb, not up to Corvette Z06 levels but still able to carry lots of speed thanks in part to a 1.4-mm-larger front anti-roll bar and 1 degree of negative camber (the previous GT500 had 0.8 degrees).
On the Atlanta Dragway, we sampled , a new technology on the 2013 GT500 that's designed for dry high-grip situations and is intended to make typical GT500 drivers be able to post excellent acceleration numbers. Here's how: With traction control off, push the LC button on the left side of the dash. Clutch in. Put it in 1st. Then floor the throttle, at which point the rpm stay at a predetermined setting. Next, the driver lets out the clutch and keeps the accelerator pinned while the ECM expertly manages wheelspin via automatic brake and throttle intervention.
It works well. I was able to post several quarter-mile passes in the 12.3 second range, at around 120 mph. And one of the SVT engineers said that 9 times out of 10, he's faster with Launch Control than without. What makes the Ford different from other launch controls? Via controls on the steering wheel, the launch rpm can be varied in 100-rpm increments to suit the conditions. For the record, Ford says the GT500 can hit 60 mph in 3.7 seconds and blast through the quarter mile in 11.7 sec at 135 mph, figures that are very similar to the Ford GT supercar's. Sixty, of note, is reached in 1st gear, so that time is unaffected by a gear change.
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2013 Shelby GT500 Burnout
On the road, the GT500 feels fast, but it lacks the absolute smack-in-the-back hit of a Corvette Z06 in a roll-on test in, say, 3rd gear. Chalk it up to its several hundred pounds of extra weight and high gearing that finds the car loafing along at 1450 rpm at 60 mph in 6th gear. And at 100 mph, the engine is only turning 2000 rpm. Nevertheless, it's still quite potent, and even though the clutch pedal is a tad heavy, the GT500 is a remarkably easy car to drive. Do, however, keep the traction control on for a while, as this car can easily spin its rear wheels in 1st, 2nd and 3rd gears.
So, what would we choose: the Boss 302 or the 2013 Shelby GT500? It's a tough call because they are very different cars. The Boss is for road racing, a pure delight with its lighter weight, shorter gearing and more pointable nature. But the GT500, with its cockpit-adjustable dampers and new launch control software, is super impressive in its reasonable price (given its power) and its ability to wear three hats well—that of "Dragstrip King, Road Course Warrior and Boulevard Cruiser," in the words of Steve Ling, the SVT Marketing Manager. And with only about 4000 Shelby GT500s expected to be sold per year, why not buy the most potent Mustang you can buy?
When we asked the SVT folks about the GT500's test times around the Nürburgring Nordschleife in Germany, they politely declined to answer the question. They did, however, encourage us to pit the car against the Chevy Camaro ZL1 on any track, at any time. Here's my quick seat of the pants assessment: I suspect the GT500 will be faster in acceleration, but the ZL1, though heavier, will perhaps have a slight cornering advantage because it's wider and feels like it has a lower enter of gravity.
Needless to say, we plan to take the SVT folks up on their offer...