PONTIAC, Michigan — FiatChrysler’s SRT boffins have created the company’s most powerful production engine ever for the 2018 Dodge Challenger SRT Demon, making an SAE-certified 840 horsepower and 770 pound-feet of torque on 100-octane-plus race fuel, or 808 horsepower and 717 pound-feet on 91 octane Premium. That’s good for a factory-official quarter-mile time of 9.6-seconds at 1.8-g’s acceleration, according to Advanced and SRT Engineering director Chris Cowland. By comparison, a Tesla Model S can accelerate at a rate of up to 1.4 g’s (based on car magazine testing), says FiatChrysler passenger car chief Tim Kuniskis.
The SRT boffins sold FiatChrysler CEO Sergio Marchionne on the idea about two years ago by proposing “a low 10-second musclecar,” Kuniskis says, with 50 more horses than the Dodge Challenger SRT Hellcat’s, for 777 horsepower. SRT over-delivered and brought the project under-budget, with numbers worthy of Marchionne’s other automaker, in Maranello.
“There’s a reason it’s red,” Cowland joked about the engine block, when asked whether Ferrari engineers have been to visit Auburn Hills HQ. But horsepower isn’t the biggest story, according to Cowland.
“The torque number is the reason this car is so fast,” he says.
At its New York International Auto Show launch, Dodge SRT announced that with a 3.9-psi Torque Reserve system boost generating 221 pound-feet, total launch torque is 405 pound-feet. Another 8.3 psi of boost from the street legal drag racer’s Torque Reserve and TransBrake adds 317 pound-feet of incremental torque, for a total of 534 pound-feet at launch. This is the sort of head-spinning math and engineering that SRT offered up in an embargoed presser at the M1 Concours in Pontiac.
Based on the dollar value of components, SRT considers 62 percent of the Demon engine to be new and unique to the Hellcat Hemi. This includes the block, crank, connecting rods, pistons and supercharger. The maximum horsepower comes in at the 6,300 redline, which is up 300 revs over the Hellcat V-8. The supercharger’s maximum boost is 14.5 psi, compared with 11.6 psi for the Hellcat engine.
The Demon supercharged Hemi V-8 comes standard with the 8-speed automatic that’s optional on the Challenger Hellcat. Shifts have been slowed slightly to 400 milliseconds for the road, and speed up to 200 milleseconds in track mode. The Demon’s rear axle is a 3.09:1, instead of the 2.62:1 in the Hellcat.
SRT attributes 15 horses of the gain to its Air Chiller, which feeds air conditioning to the coolant when under high race loads, thus dropping engine temperature by 10 degrees Celsius. A two-stage pressure system determines whether there’s race fuel or 91-octane in the system, causing the knock system to revert to standard calibration if the octane is too high. At the rated horsepower, Cowland says, the fuel flow is 1.36-gallons per minute.
Even running the 91 octane, Kuniskis says, the Demon covers the quarter-mile at 9.87-seconds at 136 mph. “It does 11.6-flat in Eco mode.”
EPA fuel economy numbers aren’t yet available, he said. There is no cylinder shutoff, but the Demon meets low-emissions vehicle (LEV) and full onboard diagnostic (OBD II) standards, as well as SAE J2805 pass-by noise standards. It meets SRT durability standards, with full SRT warranty, Kuniskis adds.
The passenger car chief figures Demon already has done its part as a halo for the Dodge Challenger, a large-for-its-class pony/musclecar on sale with few changes for a decade, now. Dodge will sell just 3,000 of the ‘18 Demons in the U.S. and 300 in Canada, but Kuniskis says Challenger website traffic is up 50 percent and pricing inquiries are up 20 percent so far, for the first five months of this year. Through May, 2017 Dodge Challenger sales is within 10,000 units of the Ford Mustang, and within just 3,000 units of the Chevrolet Camaro, and that’s without a rental fleet-friendly convertible available from those competitors.
So say you’re one of the lucky 3,300 who’s laid out $85,090 (U.S.) for a 2018 Dodge Challenger SRT Demon. Can it race in anything other than a quarter-mile of straight drag strip? Yes, Kuniskis says. It “rides like a Hellcat with a little more compliance.”