The Ram TRX comes from Dodge with a supercharged 6.2 L Hemi V8 making 702 hp. However that is not enough for Hennessey Performance. They swapped the factory motor for a supercharged 426 ci Hellephant V8 that typically makes 1000 hp and 969 lb-ft of torque. Once again that is not enough for the company. So they upgraded the supercharger and installed larger injectors to boost the engine’s output to 1,200 hp. That power is routed through 6×6 locking rear axles to Hennessey 20-inch wheels to 37-inch offroad tires.
Source: Hennessey Performance