In introducing the 2015 Dodge Challenger SRT Hellcat with 707 horsepower and 650lb-ft of torque, the Chrysler Group is showing that they might not have the bestselling muscle car in America, but they are very capable of making the most powerful muscle car. More so, it will be difficult for General Motors or Ford Motor Company to come up with a street legal engine that will beat the Hellcat so maybe – just maybe – this monster Hemi will serve as the most powerful muscle car engine of all time.