Electric Off-Road Racing Technology: The ODYSSEY 21 and the Future of Desert Motorsport
Electric propulsion has fundamentally altered the performance envelope of off-road racing vehicles. The ODYSSEY 21 electric SUV, developed by Spark Racing Technology for the Extreme E championship, demonstrated across five seasons of competition that electric drivetrains offer characteristics uniquely suited to desert terrain—instantaneous torque delivery, precise power modulation through electronic controls, regenerative braking capability, and mechanical simplicity that reduces failure points in harsh environments. What began as a concept car for a fledgling championship has become a technology demonstrator that is reshaping how the motorsport industry thinks about powertrain architecture for off-road competition.
This technical analysis examines the ODYSSEY 21 platform in detail, explores the engineering challenges of electric off-road racing, and assesses the technology pathways that will define the next generation of electric competition vehicles for desert and cross-country events.
The ODYSSEY 21 Platform: Technical Specifications and Architecture
The ODYSSEY 21 was designed and built by Spark Racing Technology, the French company that also manufactures the Gen2 and Gen3 Formula E cars. The platform was conceived specifically for the demands of off-road electric racing, incorporating lessons from both Spark’s single-seater experience and input from off-road specialists with backgrounds in rally raid, rallycross, and trophy truck competition.
Chassis and Structure
The ODYSSEY 21’s chassis is a tubular steel spaceframe, a construction method chosen for its combination of strength, repairability, and cost-effectiveness. Unlike the carbon fiber monocoques used in Formula E and Formula 1, a tubular spaceframe can be repaired in the field using relatively simple tools and techniques—an essential consideration for a championship that races in remote locations far from sophisticated fabrication facilities.
The spaceframe is built around a central survival cell that meets FIA safety standards for cross-country racing. The roll cage is integrated into the primary structure rather than bolted on as a secondary element, providing continuous load paths that distribute crash energy throughout the chassis rather than concentrating it at attachment points.
The overall dimensions of the ODYSSEY 21 are substantial: approximately 4,400 millimeters in length, 2,300 millimeters in width, and 1,860 millimeters in height. The wheelbase of 2,900 millimeters provides stability over rough terrain while allowing sufficient articulation for the suspension to work effectively over obstacles.
The body panels are constructed from lightweight composite materials, designed to be quickly replaceable after the impacts that are inevitable in off-road racing. The aerodynamic development of the body is minimal compared to single-seater racing cars—at the speeds and on the surfaces where the ODYSSEY 21 operates, aerodynamic downforce is largely irrelevant. Instead, the body is shaped to manage airflow over and around the cooling system intakes and to minimize drag on the high-speed desert sections.
Powertrain Architecture
The ODYSSEY 21’s electric powertrain represents one of the most interesting architectures in contemporary motorsport. The system uses two electric motors—one driving each axle—to provide all-wheel drive, as detailed in Extreme E racing at NEOM. This configuration offers several advantages over a single-motor layout with mechanical differentials and transfer cases.
Each motor produces approximately 272 horsepower (200 kW), giving a combined system output of 544 horsepower (400 kW). Peak torque from each motor is approximately 306 pound-feet, with the total system torque of 612 pound-feet available instantaneously from zero RPM. This characteristic—the ability to produce maximum torque from a standstill—is perhaps the single most significant advantage of electric propulsion in off-road racing.
In a conventional internal combustion off-road vehicle, the engine must build RPM before producing peak torque, and the power must then be transmitted through a clutch, gearbox, transfer case, and differentials before reaching the wheels. Each element in this drivetrain chain introduces losses, complexity, and potential failure points. The ODYSSEY 21’s direct-drive electric motors eliminate all of these intermediate components, delivering power to the wheels through simple reduction gearboxes with minimal parasitic losses.
The dual-motor layout also enables sophisticated torque vectoring without mechanical differentials. By varying the power output of the front and rear motors independently, the electronic control system can adjust the front-to-rear torque split in real time, responding to changes in surface conditions, driver inputs, and vehicle dynamics. This capability is particularly valuable in desert racing, where the surface can transition from firm compacted sand to loose dunes within a few meters.
Battery System
The ODYSSEY 21’s battery pack was supplied by Williams Advanced Engineering (now Fortescue Zero), the technology division of the Williams Formula 1 team. The lithium-ion battery pack has a capacity of 54 kilowatt-hours, housed in a protective enclosure mounted in the floor of the chassis between the axle lines.
The battery pack architecture uses pouch-format lithium-ion cells arranged in modules. The cell chemistry—a nickel-manganese-cobalt (NMC) formulation—was selected for its balance between energy density (maximizing the amount of energy stored in a given weight and volume), power density (the ability to deliver high current for the intense discharge demands of racing), and thermal stability (resistance to thermal runaway under extreme operating conditions).
The pack’s structural design incorporates multiple layers of protection against the impacts and vibrations inherent in off-road racing. The outer casing is constructed from aluminum alloy panels reinforced with steel impact structures at critical points. Internal crash structures separate the cell modules, preventing a breach in one area of the pack from propagating to adjacent modules.
Thermal management of the battery pack is one of the most critical engineering challenges in the ODYSSEY 21. The pack generates significant heat during both discharge (when the motors are drawing power) and charge (during regenerative braking), as detailed in the AlUla desert X-Prix. In the desert environments where Extreme E races, ambient temperatures compound the internal heat generation, creating conditions where the battery can approach its thermal limits rapidly.
The cooling system uses a liquid-cooled circuit with glycol-water coolant circulating through channels integrated into the battery pack’s structure. The coolant absorbs heat from the cells and carries it to a front-mounted radiator, where it is dissipated to the atmosphere. The effectiveness of this system is directly affected by ambient temperature—the smaller the difference between coolant temperature and ambient temperature, the less effectively the radiator can reject heat.
In desert conditions, where ambient temperatures can exceed 40 degrees Celsius, the cooling system must work exceptionally hard to maintain battery temperatures within the optimal operating window of approximately 25-45 degrees Celsius. When battery temperature rises above this window, the management system reduces available power to protect the cells—a phenomenon known as thermal derating that directly impacts performance.
Teams competing in Extreme E invested significant development resources in optimizing battery cooling for desert conditions. Strategies included enhanced air ducting to the radiator, pre-cooling the battery pack before racing stints, and software modifications to manage power delivery patterns that minimized peak heat generation.
Suspension System
The ODYSSEY 21’s suspension system is designed for the extreme demands of off-road racing at speed. Both front and rear axles use double-wishbone configurations with coilover damper units providing approximately 350 millimeters of wheel travel—roughly four times the travel of a Formula 1 car.
The suspension geometry is optimized for the specific requirements of high-speed off-road running. The anti-dive characteristics on the front axle are calibrated to resist the nose-down pitch that occurs during braking on loose surfaces, maintaining consistent geometry through deceleration phases. The anti-squat characteristics on the rear axle manage the rearward weight transfer during acceleration, preventing the rear of the car from sitting down excessively under power.
The dampers themselves are triple-rate units, meaning they provide three distinct levels of resistance depending on shaft speed. At low shaft speeds (corresponding to body roll and pitch changes during cornering and braking), the dampers provide firm resistance to control body movement. At medium shaft speeds (corresponding to bumps and undulations in the terrain), the dampers soften to allow the wheels to follow the terrain without transmitting excessive force to the chassis. At very high shaft speeds (corresponding to sharp impacts from rocks, jumps, and sudden compressions), the dampers open further to absorb the energy without overwhelming the chassis structure.
The spring rates are carefully matched to the damper characteristics. Progressive-rate springs (where the spring rate increases as the spring compresses) are used to provide a comfortable initial response to small terrain variations while preventing the suspension from bottoming out under heavy loads, as detailed in sustainability initiatives at Extreme E events.
Ground clearance is set at approximately 350 millimeters, providing adequate protection for the underbody components—particularly the battery pack—while maintaining a center of gravity low enough for acceptable stability during high-speed cornering.
Traction Control and Vehicle Dynamics Systems
The ODYSSEY 21’s electronic systems represent perhaps the most sophisticated aspect of the entire vehicle. The traction control system, stability control system, and power management system work together to manage the car’s behavior in conditions where the relationship between driver inputs and vehicle response is constantly changing.
The traction control system monitors the rotational speed of all four wheels and compares them to the expected speeds based on vehicle velocity and steering angle. When a wheel begins to spin faster than expected (indicating loss of traction), the system reduces motor torque to that axle to restore grip. The speed and sensitivity of these interventions are adjustable, and teams invested heavily in developing calibrations optimized for specific surface types.
The stability control system monitors yaw rate (the car’s rotational velocity around its vertical axis) and compares it to the expected yaw rate based on steering angle and vehicle speed. When the actual yaw rate diverges from the expected value—indicating either understeer or oversteer—the system applies differential braking and torque modulation to correct the deviation.
In desert conditions, the interaction between traction control and stability control creates complex calibration challenges. The traction control system must allow enough wheelspin for the car to maintain forward progress in soft sand (where some degree of wheelspin is actually necessary for propulsion), while preventing the excessive wheelspin that wastes energy and creates dangerous handling characteristics. Similarly, the stability control must allow enough yaw to enable the car to rotate through corners on loose surfaces (where some degree of oversteer is the fastest technique), without permitting the uncontrolled spins that result from excessive rotation.
The best Extreme E teams developed adaptive calibrations that used machine learning algorithms to modify these parameters in real time based on sensor data. These systems could identify changes in surface type—from compacted sand to loose sand to gravel—and adjust the electronic behavior accordingly, without requiring driver intervention.
Performance Characteristics: Electric vs. Internal Combustion Off-Road
The ODYSSEY 21’s performance in desert racing conditions revealed several fundamental advantages—and some notable limitations—of electric propulsion compared to the internal combustion engines that have traditionally powered off-road competition vehicles — a topic explored further in Saudi Arabia’s racing drivers.
Acceleration and Torque Delivery
The most obvious advantage of electric propulsion is the instantaneous availability of maximum torque. The ODYSSEY 21 can deliver its full 612 pound-feet of torque from zero RPM, with no turbo lag, no clutch engagement delay, and no need to reach a specific engine speed before peak torque becomes available.
This characteristic transforms the driving technique required for fast off-road driving. In a conventional internal combustion vehicle, extracting maximum acceleration from loose surfaces requires careful clutch modulation and precise throttle control to match engine speed to wheel speed. In the ODYSSEY 21, the driver can demand full torque immediately, and the electronic systems manage the delivery to maximize traction.
The practical result is that the ODYSSEY 21 can accelerate from standstill to 100 kilometers per hour in approximately 4.5 seconds on hard surfaces—impressive for a vehicle weighing 1,780 kilograms. On loose sand, the acceleration is slower due to reduced traction, but the electric torque delivery still provides a significant advantage over equivalent internal combustion vehicles, which lose effectiveness on loose surfaces as their engines struggle to maintain the RPM range where peak torque is available.
Weight and Center of Gravity
The ODYSSEY 21’s battery pack, while representing a significant portion of the vehicle’s total mass, is positioned in the floor of the chassis, resulting in a low center of gravity. This positioning provides stability benefits that partially offset the weight penalty of the battery.
In off-road racing, a low center of gravity reduces the tendency for the vehicle to roll over during high-speed cornering or when traversing side slopes. The ODYSSEY 21’s center of gravity height is approximately 600 millimeters—comparable to or lower than many internal combustion off-road racing vehicles where the heavy engine is mounted higher in the chassis.
However, the total weight of 1,780 kilograms is significant. Equivalent internal combustion vehicles (such as the cars competing in the Dakar Rally’s T1 category) typically weigh between 1,200 and 1,500 kilograms. The additional weight of the battery affects acceleration on steep gradients, increases braking distances, and amplifies the forces transmitted through the suspension during impacts—requiring stronger (and heavier) suspension components, which further increases the overall mass.
Range and Energy Management
The most significant limitation of the ODYSSEY 21’s electric powertrain is its range. The 54 kilowatt-hour battery provides enough energy for the short, intense stints of Extreme E’s format (typically 15-20 minutes of racing per stint), but would be inadequate for the multi-hour stages of a rally raid event like the Dakar Rally, as detailed in Gen3 electric racing technology.
Energy management during racing is a critical skill for both drivers and engineers. The available energy must be distributed across the entire stint, accounting for the varying demands of different course sections. Fast, flat sections consume less energy per kilometer than technical sections with heavy acceleration and braking, while climbing gradients demands significantly more energy than descending.
Teams developed sophisticated energy management strategies that balanced aggressive driving in critical sections (where position could be gained or lost) with more conservative energy use in less critical areas. The most effective strategies used predictive models that estimated energy consumption for the remaining course based on terrain data, adjusting the available power level in real time to ensure the car completed the stint without running out of energy.
Regenerative Braking in Off-Road Conditions
Regenerative braking—the process of using the electric motors as generators during deceleration, converting kinetic energy back into electrical energy stored in the battery—is a standard feature of electric vehicles. In on-road applications, regenerative braking can recover 10-30 percent of the energy used during driving, extending range significantly.
In off-road conditions, regenerative braking is both more challenging and more valuable. The challenge arises from the unpredictable surface conditions—on loose sand or gravel, applying regenerative braking can lock the wheels or cause them to lose traction, leading to loss of control. The value comes from the frequent deceleration demanded by the terrain, with multiple braking events per lap creating opportunities for energy recovery.
The ODYSSEY 21’s regenerative braking system was calibrated to work in conjunction with the conventional friction brakes. At low deceleration levels, regenerative braking alone provided the braking force, recovering energy without engaging the friction brakes at all. At higher deceleration levels, a blend of regenerative and friction braking was applied, with the balance managed by the electronic control system to maintain stability.
The most sophisticated teams developed regenerative braking maps that adjusted the regeneration level based on surface conditions. On firm surfaces where grip was available, higher regeneration levels could be used safely. On loose surfaces, the regeneration was reduced to prevent wheelspin, with the friction brakes taking a greater share of the braking load.
Desert-Specific Engineering Challenges
Sand Ingestion and Filtration
The fine sand particles encountered in Saudi Arabian desert racing create serious engineering challenges for all vehicles, but electric vehicles face specific vulnerabilities. While electric motors are inherently sealed and resistant to contamination, the cooling systems, electronic control units, and electrical connectors are all susceptible to sand damage, as detailed in the motorsport-automotive industry connection.
The primary concern is the cooling system. Air-cooled components—including the battery pack’s radiator and the motor controllers’ heat sinks—rely on a flow of clean air to reject heat. Sand particles in the airflow can clog radiator fins, reducing cooling efficiency, and can erode the surfaces of heat exchangers, reducing their thermal conductivity over time.
Teams competing in Saudi Arabia developed multilayer filtration systems for all air intakes. These systems typically consisted of a coarse pre-filter (to capture large particles), a main filter element (to capture fine particles), and in some cases an electrostatic layer to attract the finest particles that would pass through conventional media.
The challenge was balancing filtration effectiveness against airflow restriction. More aggressive filtration captured more particles but reduced the volume of air reaching the cooling system, potentially creating more thermal problems than it solved. The optimal solution was a system that maintained adequate airflow while capturing the vast majority of particles large enough to cause damage—a balance that required extensive testing and iteration.
Thermal Management in Extreme Heat
Operating temperatures in the Saudi Arabian desert regularly exceed 45 degrees Celsius during summer months, with ground surface temperatures reaching 70 degrees Celsius or higher. Even during the cooler months when Extreme E events were typically scheduled, ambient temperatures of 30-40 degrees Celsius were common.
These temperatures create cascading thermal challenges throughout the vehicle. The battery pack’s optimal operating temperature of 25-45 degrees Celsius means that in the hottest conditions, the battery may already be near its upper temperature limit before any racing has taken place. The motors, which generate significant heat during operation, must reject that heat to an ambient environment that is already extremely warm. The electronic control systems, designed to operate within temperature ranges typical of European or North American environments, may reach thermal limits that trigger protective shutdowns.
The ODYSSEY 21’s cooling architecture addressed these challenges through a combination of liquid cooling (for the battery and motors) and enhanced air cooling (for electronic systems). Pre-cooling strategies—running the cooling systems at maximum capacity before driving stints to bring component temperatures as low as possible—proved effective at extending the available racing time before thermal derating occurred.
Some teams experimented with phase-change cooling materials—substances that absorb significant amounts of heat energy as they transition from solid to liquid—as supplementary cooling for the battery pack. These materials provided a thermal buffer that could absorb heat spikes during intense acceleration and braking, smoothing the thermal profile and reducing peak temperatures, as detailed in the official Formula E championship.
Dust and Static Electricity
The fine sand particles generated during desert driving create static electricity through triboelectric charging—the same phenomenon that causes static shocks from walking on carpet. In an electric vehicle with high-voltage systems operating at 800 volts, static electricity from sand interaction presents unique risks.
The ODYSSEY 21’s high-voltage system includes comprehensive grounding and shielding to prevent static discharge from affecting sensitive electronics. All high-voltage connectors use sealed, insulated housings that prevent sand particles from bridging between conductors. The battery management system includes monitoring for ground fault conditions that could indicate a static discharge event.
Despite these precautions, teams operating in Saudi Arabia reported occasional electronic anomalies that were attributed to static electricity. These included spurious sensor readings, communication dropouts between control units, and in rare cases, brief interruptions to motor control signals. While none of these events resulted in safety-critical failures, they represented an ongoing engineering challenge that required constant vigilance and iterative improvement.
The Future of Electric Off-Road Racing Technology
The ODYSSEY 21 platform, while groundbreaking, represents the first generation of purpose-built electric off-road racing vehicles. The technology pathways emerging from Extreme E’s competitive experience point toward significant advances in performance, range, and capability.
Solid-State Batteries
The most transformative technology on the horizon for electric off-road racing is solid-state battery chemistry. Current lithium-ion batteries use liquid electrolytes that impose fundamental limitations on energy density, thermal stability, and charge rate. Solid-state batteries replace the liquid electrolyte with a solid material, enabling higher energy densities, faster charging, and improved thermal stability.
For off-road racing, solid-state batteries could address the ODYSSEY 21’s most significant limitation—range. A solid-state battery of the same weight as the current lithium-ion pack could provide two to three times the energy storage, enabling longer racing stints or reducing vehicle weight for equivalent range.
Hydrogen Fuel Cell Hybridization
Extreme E’s successor series, Extreme H, is designed around hydrogen fuel cell technology. The hydrogen fuel cell generates electricity from hydrogen and oxygen, producing only water as a byproduct. The fuel cell can operate continuously as long as hydrogen is available, eliminating the range limitations of battery-only systems.
In the Extreme H concept, a hydrogen fuel cell provides sustained power output while a smaller battery pack (compared to the ODYSSEY 21’s) handles peak power demands and regenerative braking energy storage. This hybrid architecture combines the instant responsiveness of electric motors with the range capability of a fuel-based energy source.
Advanced Motor Technology
Current electric motors in racing applications use permanent magnet synchronous designs, which offer the best combination of power density and efficiency for the size and weight constraints of a racing vehicle. However, emerging motor technologies—including axial flux motors, switched reluctance motors, and superconducting motor concepts—promise further improvements in power density and efficiency.
Axial flux motors, in particular, are attracting significant interest for racing applications. Their pancake-like form factor allows them to be integrated directly into the wheel hub, eliminating the reduction gearbox and half-shaft that connect the ODYSSEY 21’s motors to its wheels. This configuration reduces unsprung mass (improving suspension performance), eliminates drivetrain losses, and provides the ability to control the torque at each wheel independently—the ultimate form of torque vectoring.
Conclusion: Electric Propulsion’s Desert Proving Ground
The Extreme E championship, racing across the deserts of Saudi Arabia and other challenging environments, has demonstrated that electric propulsion is not merely viable for off-road competition but offers fundamental advantages that will reshape the discipline. The ODYSSEY 21’s instantaneous torque delivery, precise electronic control, and mechanical simplicity proved their worth in some of the most demanding conditions motorsport can encounter.
The technology challenges that remain—thermal management in extreme heat, range limitations for longer formats, and the weight penalty of current battery technology—are being addressed through research programs that benefit from the competitive pressure and real-world data generated by racing. Each Extreme E event in the Saudi Arabian desert produced insights that advanced the state of electric off-road technology, creating a feedback loop between competition and development that accelerates progress beyond what laboratory testing alone could achieve.
As the motorsport industry looks toward a future where electrification is not optional but inevitable, the lessons learned from electric SUVs charging across the Saudi Arabian desert will prove to be among the most valuable in shaping the technology, regulations, and competitive formats that define the next era of off-road racing.