It’s been ten years since Dodge dropped a bomb on the automotive world with a single number: 707. That was the horsepower figure for the then-new 6.2-liter supercharged HEMI, an engine codenamed Hellcat that didn’t just join the modern horsepower war—it reset the entire battlefield. The Hellcat put Detroit’s rivals and expensive European supercars on notice, kicking off a 10-year reign of tire-shredding dominance that has become the stuff of legend.

Photo credit to: Dodge Garage

The Secret Mission in Auburn Hills

The vision for the engine started with then-Dodge boss Tim Kuniskis, but the secret mission to build it fell to a dedicated team of Street & Racing Technology (SRT) engineers in Auburn Hills, Michigan. Jim Wilder, a development manager on the project, recalled that the initial test mules started with a 6.4-liter HEMI and an aftermarket blower making just over 600 horsepower. Right away, the team ran into their biggest challenge: cooling. Wilder remembered the battle, saying, “I didn’t make friends in the studio with requests and demands for more airflow through the grill.”

Photo credit to: Dodge Garage

Engineering a Supercharged HEMI

Making big power was only part of the challenge. The team had to ensure the engine could survive, pass strict emissions tests, and, just as importantly, sound right. “A muscle car needs to sound good and tough,” Wilder noted. “That’s not a line on a chart or curve — it’s your ears telling you that the sound matches the car.”

Engineers painstakingly balanced the iconic supercharger whine with the deep V8 rumble, creating a signature sound that became instantly recognizable.

Photo credit to: Dodge Garage

The Big Reveal and a Legendary Name

The project was so secretive that few people at the company even knew about it. The Hellcat name itself was an internal code name, following SRT’s tradition of naming engines after military aircraft, in this case, the iconic WWII Naval fighter. When the team realized that over 700 horsepower was achievable, 707 was set as the target because it had a nice ring to it.

Photo credit to: Dodge Garage

A Decade of Dominance

After debuting in the 2015 Challenger and Charger, the Hellcat’s influence spread. This incredible supercharged HEMI would go on to power the Jeep Trackhawk, Dodge Durango, and Ram 1500 TRX. It also served as the foundation for even wilder creations like the Redeye, Demon, and Demon 170 models, cementing its place as one of the most important and fearsome V8 engines of the 21st century.