14. 6.2-liter Hemi Demon V8
If you think the insane Hellcat V8 with 707 HP is not powerful enough, there is the 6.2-Liter Demon V8 built by the same guys in the Chrysler SRT department. This powerplant delivers 820 HP and is available in limited production. It is also in the track-ready Dodge Challenger Demon.
The Demon is more than a Hellcat with more boost and over 100 HP more. Even though these two engines share similar architecture and blocks, there are over 25 important differences between the two.