Horses and snakes don’t necessarily play well together in nature, but on a racetrack they’re a legendary pairing. Ford Mustangs adorned with a Shelby Cobra badge are purpose-built to chase lap times and capture checkered flags. The GT350 and upcoming GT500 are the most performance-oriented Mustangs ever, but looking beyond the coiled snake in their grilles shows key differences that give each car its own distinct character.
The GT350 and GT500 both have 5.2-liter V-8s, but don’t let that fool you into thinking the engines are similar. The GT350’s is equipped with a flat-plane crankshaft, a differentiator that completely alters its function. A flat-plane crankshaft has 180 degrees of rotation between crank throws, alternating the firing order between each cylinder bank. This improves airflow through the engine; as one side fires the other evacuates gasses in its exhaust manifold, reducing backpressure. The effect is an engine that breathes more freely and revs more readily. However, this side-to-side firing order produces vibrations that can make a car less comfortable on the street and can even stress the engine internals with large-displacement engines. The GT350 uses a special harmonic balancer to help smooth things out.
The GT500’s engine uses a more common cross-plane crankshaft design. It has 90 degrees of rotation between crank throws; those smaller intervals produce more regular firing. However, since the firing order is unevenly spaced between cylinder banks, heavy counterweights are required to balance out vibrations. Those add rotating mass, making cross-plane engines less free-revving and responsive. Still, the tighter firing provides smoother power delivery and improved torque, especially at low rpm—not to mention that unmistakable V-8 sound.
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Further distinguishing the engines is the fact that the GT350’s is naturally aspirated, while the GT500’s will be supercharged. We’ve waxed poetic about how the GT350’s 526 horsepower and 429 lb-ft of torque are delivered near its 8,200-rpm redline. That sky-high limit is enabled by that lightweight flat-plane crank and contributes to the car’s purpose as a track tool.
Meanwhile, the GT500 is supercharged for better low-end torque, as that’s what the GT500 is known for. Ford hasn’t revealed the 2020 GT500’s power figures, so far only saying it will make more than 700 horsepower and 600 lb-ft. (Update: Ford has confirmed the GT500’s horsepower and torque figures.) We’ll relay exact power figures as soon as Ford discloses them, but given what we know about supercharged cross-plane V-8s, it will have a different, more muscular character than the GT350.
Behind two very different engines are two very different transmissions. The GT350 has a six-speed manual, allowing complete driver control befitting of the car’s track orientation (a mien it leans even harder toward in GT350R guise). The GT500 loses a pedal but gains a gear. A Mustang-first dual-clutch transmission with seven forward ratios is promised to provids near-instantaneous shifts, so there’s no loss of power whether lapping a road course or tearing down a drag strip.
Airflow—both over and through the car—is more of a focus on the GT500 than the GT350. That’s apparent when you compare the two cars’ front ends. The GT500’s has double the open area of the GT350, as well as a metal mesh grille that’s thinner and blocks less air than the GT350’s injection-molded plastic piece (the GT350’s grille opening actually shrunk for 2019 to reduce the front-end lift produced by surplus air getting trapped under the hood). The extra air needed to feed the GT500’s six heat exchangers exits through ducts in the wheel arches and the 6.03-square-foot vent in the carbon-fiber hood—compare that to the little slit in the GT350’s engine cover.
For 2019, the GT350 gained a new rear wing that’s shared with the standard GT500. With an optional Gurney flap, it produces up to 281 pounds of downforce at some unspecified speed. However, the GT500’s available Carbon Fiber Track Package fits the car with the adjustable wing straight off the Mustang GT4 race car, which pushes the rear end into the ground with 550 pounds of downforce. Dive planes on the front bumper help keep the nose planted.
READ MORE: 2019 Ford Mustang Shelby GT350 Driven!
Body and Chassis
Park the cars next to each other and you’ll see that the GT500 has broader shoulders than the GT350. That’s due to the composite front fenders Ford developed specifically for the car, necessary to cover the wider front tires, which as standard are Michelin Pilot Sport 4S. Opting for the Carbon Fiber Track Package, however, adds 20-inch carbon-fiber wheels (0.5 inch wider in the rear) wrapped in Michelin Pilot Sport Cup 2 tires. Ultra-light carbon-fiber 19-inch wheels are standard on the GT350R. Regardless, the GT350 has 15.5-inch front Brembo brake rotors, clamped by six-piston calipers. Those grow to 16.5 inches in the GT500, representing a 20-percent increase in swept area. Both Mustangs ride on magnetic dampers, albeit with different tunes depending on the car and how they’re equipped. No matter the case, Ford’s super-Stangs are the best of the breed.