Car News

Dodge Gives Up Demon Powertrain's Secrets

Dodge has revealed more details about the 2018 Challenger SRT Demon's engine and powertrain. They want you to know that the 840 hp supercharged 6.2L V8 engine is more than just a Hellcat with more boost.

The big number is that power output. Dodge claims 840 hp and a massive 770 lb-ft of torque. That's if you get the optional Direct Connection controller and are able to find 100 octane (or better) gas. Since race gas can be hard to find, and will set you back a lot more than anything your local station sells, the Demon has a street gas program too. On 91 octane fuel, the Demon delivers a still-absurd 808 hp and 717 lb-bt of torque. That's 101 hp more than the Hellcat.

Dodge says the Demon's engine is 62 percent new compared with the Hellcat V8. It has unique pistons, connecting rods, a different supercharger, and even the block is different for the Demon. Dodge puts every Demon and Hellcat V8 on a dyno for 42 minutes, testing it under load before installing them into a car.

The supercharger is completely new for the Demon. It displaces 2.7L of air per revolution, with rotors 28mm longer than the Hellcat's. It makes up to 14.5 psi of boost, 2.9 psi more than the Hellcat, and can flow over 32,000 litres of air every minute. It has a forged steel crank with hardened bearing surfaces. Flow to the piston-cooling oil jets is doubled. Even the nuts, bolts, and other fasteners in the engine had to be beefed up for the extra power.

At full power, the Demon flows 6.17 litres per minute of gasoline. That's enough to drain the 70L tank in just 11 minutes, 20 seconds. Or by my math, about 70 quarter-mile drag strip runs. With the torque reserve and trans brake systems, the Demon can launch at 1.8g, and Dodge had to redesign the oil pan to make sure the launch didn't starve the oil pump.

To put that power to the ground, and to maximize acceleration, the rest of the driveline gets beefed up too. The limited slip differential gets a 3.09 final drive in place of the 2.62:1 in the Hellcat. That improves acceleration. The driveshaft is 20 percent thicker, with upgraded rear half shafts and upgraded bearings. And the eight-speed automatic has a torque converter with 18 percent more multiplication.

It all makes for a massively impressive powertrain. One that should arrive at Canadian dealers later this year, with most of the rest of a Dodge Challenger wrapped around it.