Steering on the Ram Rebel TRX concept is unchanged from the Ram 1500, featuring electric power steering (EPS). By using an electric motor to power the truck’s rack and pinion steering system, the engine is relieved from the task of a constantly turning hydraulic pump. Also, EPS reduces complexity by removing a pump, high-pressure hydraulic hoses and cooling apparatus. With EPS, each Rebel TRX concept can be specifically calibrated to optimize steering effort and precision regardless of body or powertrain configuration. Additionally, EPS senses constant input from the driver, for example a crown in the road, and compensates for improved comfort.
Tires and wheels
High-speed truck off-road race teams commonly use a 37-inch tire for its height and durability. The Rebel TRX is no exception and ruthless to the medium that lies between the powertrain and the ground.
Tires with 37 inches of height, 13.5 inches of width, aggressive treads and 10-ply design are assigned the task for the Rebel TRX. Tires are normally held to a wheel by air pressure. The Rebel TRX concept features custom beadlock wheels from Mopar. Beadlock wheels provide additional tire-holding strength by pinching the outside of the tire to the rim.
This increase in holding strength prevents higher horsepower vehicles from spinning the wheel inside the tire “breaking the bead.” It also allows much greater lateral pressures like those incurred in a 60 miles per hour (mph) sideways drift through rocks. Additionally, beadlocks increase run-flat operation and allow for extremely low pressure use without losing a tire off the rim.
The Rebel TRX carries two complete spare tire and wheel packages on a dedicated rack in the bed of the truck. The backup rubber allows for not one, but two tire replacements. Tools and jack are located in custom, lockable storage between the wheels in the bed.
The added weight located rearward also helps handling characteristics of the Rebel TRX.
Getting up to 100 mph is not a challenge for Ram Rebel TRX, but stopping the machine requires a four-wheel disc brake system. The factory hydraulic-boost compensation unit enhances brake pedal feel and performance during emergency stop events. Up front are Baer Brakes six-piston monoblock calipers mounted to 15-inch, two-piece slot, drilled, zinc plated rotors. The rear uses six-piston calipers with 14-inch rotors to provide incredible stopping power.
Once the powertrain engineering team was given details on performance expectations and packaging concerns for the Rebel TRX concept, it became clear only one option would meet the requirements. In order to address those demands, the Rebel TRX is driven by FCA’s supercharged 6.2-liter HEMI® V-8 with an output of 575 horsepower – the most powerful Ram 1500 the company has ever built. The V-8 mill is mated to the TorqueFlite 8HP70 eight-speed automatic transmission.
“The Rebel TRX concept demands an engine with specific abilities in a small package. Reaching such horsepower per-liter efficiencies requires forced induction,” said Bob Lee, Vice President — Engine, Powertrain and Electrified Propulsion Systems Engineering — FCA North America. “The proven supercharged 6.2-liter HEMI V-8 delivers 575 horsepower to move this 6,000-pound beast through punishing terrain at a ferocious pace.”
New calibrations were used for the engine, transmission and Ram’s 4×4 Performance Control System to optimize the expected high-speed off-road driving cycle.