The brand-new Mustang Shelby GT500 is the hottest thing to come out of Dearborn in years. Here’s what will make super snake rain fire and brimstone like the biblical end of days.
As in previous generations of this alpha Mustang, the 2020 model is powered by a supercharged V8. Anything less would be sacrilege, akin to naming an electric crossover Mach1… (We jest!) Not surprisingly, Ford is being cagey about output figures, only stating that it will deliver more than 700 horsepower. Hey, they’ve got to keep up with the folks in Auburn Hills.
For this latest Shelby, rather than starting from scratch, engineers kicked off development by reaching into the parts bin, grabbing a block from Ford’s plenty-potent Shelby GT350 Mustang. Displacing a healthy 5.2-liters, it proved a more-than-robust foundation to start with, though changes a-plenty have been made so it doesn’t crumble under the strain of copious boost.
“It’s all about making sure the engine stays together,” said Carl Widmann, Ford Performance chief engineer. The forces at work inside a supercharged powerplant are different than those found in one that’s naturally aspirated and spins north of 8,000 rpm. Appropriate changes had to be made to prevent this V8 from scattering like a fragmentation grenade the first time an owner does hot laps or blasts off down a drag strip.
The block itself, which is cast of aluminum and features a closed-deck design for added strength, has gained additional ribbing to enhance overall rigidity. That foundation is also deck-plate honed so the cylinder bores stay nice and round when the heads are bolted down. Sandwiched between these components are rugged four-layer gaskets.
As in the latest iteration of the standard 5.0-liter “coyote” V8, the bores in this supercharged engine feature plasma-transferred wire arc cylinder liners, a fancy process that basically sprays molten steel onto the bores of the aluminum block, forming a durable surface the pistons ride against. Pat Morgan, powertrain manager at Ford Performance explained this is a process they developed. It’s similar to what other companies in the automotive industry use but with some special tweaks. The main advantage of this technology is weight reduction as you don’t need heavy press-in cylinder liners.
GT500 blocks are not cast in house by Ford, but they are machined and the bores get sprayed at the company’s Essex factory in Windsor, Ontario, Canada. As with its other specialty powerplants, assembly is completed on the niche line at the company’s Romeo Engine Plant in Southeastern Michigan.
Keeping the cylinder heads securely attached, which is always a good thing, “We changed the head-bolt system design,” said Morgan. They made the fasteners longer, “So we could move the first-engaged threads down lower in the block.”
With its tight 100-millimeter bore spacing, Ford’s modular engine family could never support the gargantuan displacements GM’s LS V8 range can provide. But forced-induction is a great equalizer on both the street and strip.
With such little material between each cylinder bore strength might be a concern but Morgan says not to worry. “We’ve found over the years that this modular architecture is just really, really tough,” with customers pushing out 1,200 horsepower using stock blocks. Durability should not be an issue with the 2020 GT500.
Ensuring this beast of an engine never wants for lubricant, the oil pan has been enlarged by adding side tanks, little kick outs that increase capacity. It’s also been equipped with active baffling. “You don’t want to get oil away from the pickup. That’s really bad for the bearings when they don’t have any oil,” said Widmann with a smile. Overall crankcase capacity should measure around 11 quarts of 5W-50.
Helping the GT500 cope with strenuous on-track driving Morgan said, “We have shortened the drain interval on this,” noting that it’s been reduced to around 7,500 miles, though the car will be equipped with an oil-life monitoring system, which informs drivers when a change is required based on usage.
Seeing this engine on a stand gives you an opportunity to get a good look at it from all angles, and one interesting thing about it is how tiny the oil filter is. It looks too small even for a Fiesta hatchback, let alone a car with more than 700 horses under the hood. But according to Morgan this is not an issue. “That actually has a synthetic element in it to reduce the pressure drop across the filter.” He added that this design packages nicely in the car and provides more-than-adequate filtration capacity.
Rounding out our tour of this engine’s lower end, the new GT500 Mustang will feature a cross-plane crankshaft, rather than the more exotic flat-plane unit found in its less-potent Shelby sibling.
Moving upward, this 5.2-liter beast if force-fed by a 2.65-liter roots-style Eaton blower, one engineers worked hard to push as deep into the valley of the engine’s “V” as possible in order to keep the hoodline low. Unlike some other Ford engines, this example benefits from cast-aluminum cam covers rather than plastic ones. Morgan said they cope better with the intense heat coming off the nearby exhaust system than a composite material would.
Further keeping underhood temps in check, Widmann said the car’s overall frontal area for cooling has roughly doubled compared to the GT350.
That supercharger breaths through a massive 92-millimeter throttle body, one that looks large enough to ingest flocks of migratory birds if they were unfortunate enough to cross this car’s flightpath. Curiously, fuel is delivered by a port-injection setup. Why not go direct? Morgan said this is because DI systems often take up a lot of under-hood real estate, space they didn’t have, plus they wanted to maximize the size of the supercharger’s cooler for enhanced performance.
Getting rid of post-combustion byproducts, this blown 5.2-liter engine features the same exhaust-header design as Ford’s standard “coyote” V8. If it ain’t broke don’t fix it, right? “We’ve found it works very well to get good pulse separation, good tuning and it works for the right sound,” said Morgan. “So, it was the right combination.”
All this advanced engineering should deliver hellacious performance, a stable exceeding 700 horses. When pressed for more specific output figures Widmann responded, “We didn’t want to give you guys a new number today because we’re still working on it.” Maybe the GT500 will have closer to 800 ponies when everything’s said and done.
This car promises to be an overachiever in a segment of already-Herculean automobiles. Regardless of its final horsepower and torque figures, Widmann said the 2020 Ford Mustang Shelby GT500 will be able to hit 60 miles an hour in the mid-three-second range and eradicate the quarter-mile in less than 11. Those numbers, by anyone’s measure, are nothing short of blistering.
a version of this article first appeared on AutoGuide