
Citroen C3 ERX
The Citroën C3 ERX is the world's first all electric race car based on a Rally2 platform and tailormade for EV customer motorsport. Equipped with a FIA certified STARD EV powertrain, it is perfectly suited for rallycross, hillclimb and any other national and international sprint races.

The Citroën C3 ERX is the world's first all electric race car based on a Rally2 platform and tailormade for EV customer motorsport. Equipped with a FIA certified STARD EV powertrain, it is perfectly suited for rallycross, hillclimb and and any other national and international sprint races.
Citroën C3 ERX core values are shared with the Rally2 version : performance, reliability and cost efficiency. Citroën C3 ERX combines the best of two worlds : the successful Citroën C3 Rally2 chassis and the Austrian EV motorsport pioneer STARD´s (Stohl Advanced Research and Development) groundbreaking REVelution EV powertrain. This vehicle is the world's first true road car based customer electric motorsport vehicle with a full FIA certified EV motorsport powertrain system and battery.
Electric Powertrain
The car is equipped with STARD´s in house developed EV powertrain system which is the world´s first powertrain kit optimised for customer motorsport resulting in an unchalenged performance/cost ratio.
The powertrain system has full FIA safety certification which makes the C3 ERX the world´first ever road car based EV race car with with FIA certification and just the 2nd ever motorsport powertrain to receive this pedigree besides Formula E.
Offering 450 kW of combined power and over 1000 Nm of torque, the performance of the car is breathtaking.
The main targets for the powertrain system were :
- Safety: the STARD prepreg carbon fibre HV battery pack is situated within the safety cell of the car and can withstand 60G deceleration without damage.
- Reliability: The STARDxBRUSA E-Motors and Inverters are optimised for rough motorsport and based on road car technology which results in a perfect reliability even in harshest conditions.
- User friendliness: based on MoTeC electronic hardware with a STARD in house developed software package, the complete powertrain is extremely easy to handle for customers even without any engineer support.
Michael Sakowicz, STARD CEO: "Our powertrain system is as cost efficient, robust and easy to handle as no other system currently on the market. This is also influenced by the complete turnkey solution from one supplier, STARD, which results in all individual elements perfectly matching each other.“
The transmission is a STARD proprietary EV specific motorsport solution with unchallenged flexibility. Adjustable differentials, two gears and ratio options from 4:1 up to 14:1 for both gears offer setups from rallycross to top speeds over 300 km/h records.
Chassis and ground connection
The C3 ERX shares its rolling chassis and suspension components with Citroën C3 Rally2. As a result, performance and grip is optimised on any possible surface : from tarmac over to mixed surfaces or pure gravel with a number of setup options available.
It also guarantees a perfect quality and spare parts supply based on the proven established Rally2 concept from Citroen Racing.
Options include setups for 15“, 16“, 17“ and 18“ wheels.
Development
While the extensive development and racing activity of the Citroen C3 Rally2 chassis is well known, the STARD powertrain system has also undergone a huge amount of testing and racing activity by STARD and worldwide customers.
The Citroën C3 ERX's powertrain has completed around 10.000 km of test and race distance since middle 2019, at the hands of over 60 professional independant race drivers.
The thorough testing also covered all types of surfaces - ranging from gravel, ice, snow, tarmac and mixed surfaces - and temperatures - ranging from -20°C to 38°C - proving the functionality of the system in a wide range of possible conditions.
At its international race debut in the Projekt E race in 2020 in Riga, Latvia, Cyril Raymond has driven the car to its first race victory at its first event.
Citroën Racing and STARD are continuously developing the car further.
Marketing
The C3 ERX has been primarily developed for the FIA international series Projekt E, which was launched in 2020 as the leading electric support category in the FIA World Rallycross Championship.
However the car can be raced in a big number of international and national racing series worldwide, with additional series being added continuously.
ERX (former known as Projekt E)
DRX (German National Rallycross Championship)
BRX 5 Nations (British Rallycross Championship)
Austrian Rallycross Championship
Hungarian Rallycross Championship
Norwegian Rallycross Championship
Italian Rallycross Championship
Hillclimb Events, City Rallysprints, Rallysprint Events
If you plan to compete in a series which is not listed below, please contact STARD for support and advice.
Technical sheet
Model : STARD Citroen Racing C3 ERX
Vehicle : C3 Rally2 based, developed and built by STARD supported by Citroen Racing
Vehicle type : Electric Rally2 based AWD Race Car
Body : Citroën C3 Rally2 based bodyshell with FIA homologated rollcage
Bodywork : Citroën Racing C3 Rally2 based Carbon Fiber Bodywork
Performance :
Combined Power / Torque : 450 kW / 1002 Nm
Powertrain : STARD #REVelution RCR3b Motorsport EV Powertrain
E Motor : 3x STARDxBRUSA specific Motorsport Hybrid Snychronous Motors & Controllers
E-Motor Position : Transversely Mounted 1x Front and 2x Rear
VCU (Vehicle Congrol Unit) : Central Motec M150 VCU with STARD developed firmware
Power and Torque per Motor : 3 x 150kW / 334 Nm peak / 13.500 max rpm
Torque Distribution : STARD proprietary 2-Axle Torque Vectoring system
Battery pack (RESS) : FIA approved STARD #REVelution RESS-CR-0403-A01 Motorsport Battery Pack
Cells : STARD specific Ultra High Performance Li-ion cells
Minimum Charging Time 80% SOC : Fast DC-20 min, STD DC-56 min
Casing : FIA tested Carbon Fibre Structure with Quick Release Fixation
System Voltage / Capacity : 420 V / 35 kWh
Cooling/Heating : STARD proprietary Liquid Conditioning System
Electric / Electronic : FIA approved System and Safety Features
Wiring loom : STARD proprietary Motorsport Wiring Harness
Driver display / data logger : Motec C127 Display with Logging Function
Power distribution : Motec PDM30 Power Box with STARD Software
Transmission : STARD #REVelution 2-Motor 2-Speed Motorsport Transmission
Type : Up to 2 Motor Input (1 per side) with shared Input Shaft, 2-Speed and straight cut Gears
Position : Front 1 Transmission with 1 Motor (2nd Motor Option), Rear 1 Transmission with 2 Motors
Shifting System : Electric rotary Acutator with Dog Gears (paddle shift)
Differential : Multi-discs adjustable limited Slip Differential, external Preload adjustment
Layout : Independant Front & Rear axle, no mechanical connection Front-Rear, same Transmission Front & Rear
Suspension : Citroën C3 Rally2
Type : Citroën Racing Rally2 based Mc Pherson Front and Rear
Damper : Citroën Racing Rally2 based Reiger Dampers 3-way adjustable
Steering / Brake : Citroën Racing C3 Rally2
Steering : Citroën Racing Rally Electrohydraulic Steering System
Brake system : Citroën Racing Rally Alcon Brakes Front and Rear, blended adjustable Recuperation
Pedal box : Citroën Racing Rally Pedal Box with Brake Balance Adjuster and Rr Brake Pressure Reducer
Wheels : STARD OZ-Racing Magnesium Wheels
Dimensions
Length : 3,996 mm
Width : 1,830 mm
Wheelbase : 2,567 mm
Track Width : 1,640 mm