Citroen Sport's ecological competition concept car, the C4 WRC HYmotion4, will be unveiled at the 2008 Paris Motor Show this month.
The C4 WRC HYmotion4 concept car is the first World Rally Car to be equipped with a hybrid energy recovery system which delivers added performance and lower emissions.
A statement from the manufacturer read:
"This new concept car - which sports a split livery, with the team's familiar World Rally Championship colours on one side, and a design based on a more restful colour scheme redolent of natural materials on the other - illustrates Citroen's stand on environmental matters, including in the world of motor sport which stands out as a source of performance-related, reliable and rational technological innovations.
"The HYmotion4 system enables a proportion of the kinetic energy produced during braking to be recovered and stored. This energy is accumulated by a motor generator in the form of electricity in battery packs positioned at the rear of the car. It can then be employed either to deliver extra power when accelerating or to drive the car using emission-free electrical power alone, with no engine noise or exhaust fumes.
"This system can significantly enhance the efficiency of a competition car during the different running phases:
- Braking energy is not entirely dissipated in the environment,
- The availability of additional torque thanks to an electric motor increases the internal combustion engine's useful rev range,
- At a constant speed in electric mode, the vehicle benefits from a longer range (plus 40km), while fuel consumption on road sections is reduced by 30 per cent.
"These real performance gains have been achieved thanks to the innovative technological solutions which have been developed to transform the C4 WRC into the C4 WRC HYmotion4.
"The system comprises four key components:
- A 125kW electric motor-generator connected to the rear differential (gear driven),
- A pack of 990-cell lithium-ion batteries which deliver a voltage of 400V. Positioned over the fuel tank.
- Two additional cooling systems for the motor-generator and batteries, with a specific radiator positioned under the right-hand side of the floor.
- An electronic control unit to manage the system's power electronics circuit.
"The driver is free to select one of the four running modes using the HYmotion4 pre-selection rotary control:
- Internal combustion engine mode: the most frequently-used mode for the C4 WRC (used on stages and potentially on road sections).