The Dodge Demon represents the pinnacle of factory-built performance sedans, engineered to dominate the quarter-mile and leave competitors in its dust. Understanding what engine does a Dodge Demon have is the key to unlocking the secret behind its staggering 840 horsepower figure. This machine is not just a modified Challenger; it is a purpose-built executioner designed from the factory to obliterate expectations. The heart of this beast is a Hemi V8, but it is a specific, heavily modified iteration that sets it apart from every other vehicle on the road.
The 6.2-Liter HEMI Hellcat Redeye
At the core of the Demon's fury lies the 6.2-liter HEMI V8, specifically the Hellcat Redeye engine. This powerplant is the same unit found in the Dodge Challenger SRT Hellcat Redeye, but the Demon's implementation is far more aggressive. The engineers at Mopar dialed in the calibration to extract every possible horsepower, resulting in a certified output of 840 horsepower and a mind-bending 770 pound-feet of torque. This isn't just a number; it is a physical force that pushes the driver back into the seat with violent authority during acceleration.
Forced Induction: The Roots Supercharger
Unlike a naturally aspirated engine that relies on atmospheric pressure, the Demon utilizes a massive roots-type supercharger to cram air into the combustion chambers. This Eaton-supplied blower is a sight to behold, sitting atop the engine and feeding air directly into the intake manifold with brute force. The supercharger is responsible for the distinctive whine that precedes the Demon's launch, a sound that signals immediate violence. This forced induction system allows the small displacement V8 to outperform much larger engines, creating a power band that is both immediate and relentless.
Advanced Engineering and Forged Internals
To handle the immense power output, the Demon features a forged crankshaft, connecting rods, and pistons that are significantly stronger than standard components. The cylinder heads are specifically designed to optimize airflow and cooling, ensuring the engine remains stable under extreme conditions. Additionally, the Demon benefits from an upgraded valvetrain and high-flow fuel injectors, all contributing to the engine's ability to sustain high RPMs and produce massive amounts of power without failure. This level of engineering ensures reliability despite the immense stress placed on the motor.
Cooling and Performance Upgrades
Managing the heat generated by such a powerful engine required a complete redesign of the cooling system. The Demon comes equipped with an enlarged transmission cooler, an auxiliary transmission cooler, and a massive air-to-air intercooler. These components work in tandem to keep both the engine and the transmission within optimal operating temperatures, even during repeated hard launches or extended track sessions. Without these critical cooling upgrades, the demonic performance figures would be impossible to maintain consistently.
Transmission and Drivetrain Integration
The monstrous power generated by the engine is transferred to the rear wheels via a TorqueFlite 8HP90 automatic transmission. This eight-speed gearbox is fortified with a stronger torque converter and upgraded internal components to endure the punishing torque figures. The final drive ratio is optimized for both explosive acceleration and high-speed performance, ensuring the power is delivered efficiently to the pavement. This robust drivetrain is the unsung hero, translating the engine's fury into controlled, terrifying speed.
The Result: Unparalleled Performance Metrics
The combination of the 840-horsepower HEMI and the specialized hardware allows the Demon to achieve performance metrics that were once the realm of fantasy. It sprints from zero to 60 miles per hour in a mere 2.3 seconds and completes the quarter-mile in an eye-watering 9.65 seconds when equipped with the proper tires. These numbers are not achieved on a lightly modified road car; they are the result of a factory-built machine that treats physics as a suggestion. The engine is the catalyst that enables these breathtaking statistics.
