USED DODGE DEMON FOR SALE. Back when the Hellcat was in development, the engineers decided to see how far they could reliably push their 6.2-liter HEMI V8. The result is 840 horsepower and 770 lb-ft of torque. It is made possible by a 2.7-liter supercharger and race fuel. Racing fuel can only be utilized if you purchase the optional Demon Crate.