2025 China Endurance Championship (CEC) GTL Technical Regulations

This document is the technical rules of the 2025 CEC China Endurance Championship GTL Group. It specifies the definition, registration, requirements of various systems and components of participating vehicles in detail. The following are the specific contents:

1. Vehicle Definition and Registration

• Definition: The prototype vehicle must be a mass-produced passenger car with a production of 2,500 or more vehicles within 12 consecutive months.

• Registration: The document does not clearly mention the specific registration process and required materials.

2. Basic Requirements for Participating Vehicles

• At least one driver's door and co-pilot's door. Formula, non-hardtop vehicles, assembled steel frame vehicles and central steering wheel vehicles are prohibited from participating (except those approved by the organizing committee).

• Must be a four-wheel vehicle with front-wheel steering, rear-wheel or all-wheel drive, and only one internal combustion engine is allowed as the power unit.

• Must comply with the "Safety Modification Rules for Mass-produced Vehicles in Domestic Automobile Competitions in 2018" and these technical rules, and install the data acquisition system specified by the organizing committee.

3. Modification restrictions

• Modifications that are not explicitly permitted are prohibited, and permitted modifications must not lead to unauthorized modifications.
• Bolts, nuts, etc. can be replaced with parts of the same material, diameter and thread, and locking devices can be added.
• It is allowed to replace commercially available engine assemblies, but the air restrictor required by the group must be used, and the original vehicle firewall cannot be changed.

4. Vehicle weight

• Different engine displacements and drive forms correspond to different minimum vehicle weights. The turbine exhaust volume is calculated by multiplying the actual exhaust volume by 1.6.
• The minimum weight can be achieved by adding a ballast box in the car. The ballast box and ballast must be firmly installed. The ballast is fixed with at least 4 bolts with a mechanical energy level of 8.8 or above and a minimum diameter of 10mm. The contact area between the frame and the mounting plate at the fixing point is not less than 40cm².
• The car must meet the minimum vehicle weight limit throughout the event, especially when crossing the finish line. The organizing committee has the right to adjust the vehicle weight according to the actual power output of the engine.

5. Safety regulations

• The safety regulations in the "2018 Domestic Automobile Competition Mass Production Model Safety Modification Rules" must be followed, including requirements for additional locks, racer seats, seat belts, roll cages, fire extinguishers-fire extinguishing systems, protective nets, etc.
• For example, two safety locks are installed on the engine compartment and luggage compartment locks, and the original lock system must be removed or invalid; the seats must be replaced with competition seats that meet FIA standards, and the seat belts must meet the corresponding standards; some steel pipes of the roll cage must be wrapped with sheaths; install fire extinguisher systems and protective nets that meet the requirements, etc.

6. Engine system

• The engine must be the original engine of the participating model, the control unit must also be the original, the ignition system is not limited, and it must be equipped with an officially designated data recorder.
• There are detailed modification and restriction requirements for the cooling system, oil supply and intake system, air filter, lubrication system, cylinder head and cylinder block, flywheel, exhaust system, engine and gearbox brackets, etc.
• There are no restrictions on the modification of thermostats and fan control systems in the cooling system, but the radiator must be installed in the original position; the pipelines of the supercharger and other fuel supply and air intake systems must be in the engine compartment, and the throttle must be an original part, etc.

7. Transmission system

• The gearbox must be original, the number of clutch plates shall not exceed 2, and carbon friction plates shall not be used; the differential can be replaced with a mechanical type, and relevant heat dissipation devices can be installed; there are certain restrictions on the modification of the drive shaft, and it is recommended to add a fracture insurance mechanism to the rear drive shaft.

8. Suspension system

• The original subframe must be used, and the wheelbase must be kept within ±50mm of the original. The relative positions of the installation points of the various parts of the suspension system are subject to certain restrictions, and some parts can be modified by strengthening and replacing materials.

• The steering system is regarded as part of the suspension system, and the wheel bearings can be replaced with enhanced ones, but the type and inner diameter must be consistent with the original.

9. Wheels and tires

• The wheels must be a metal monolithic structure, and a tire nut locking mechanism can be installed. The diameter of the fixing bolts should not be less than the original factory. Each wheel is fixed with 5 screws. The maximum 18-inch × 11J wheel can be used, and the weight of a single wheel should not be less than 11 kg.
• The maximum cross-sectional width of the tire of a naturally aspirated engine corresponding to different engine displacements, the turbine exhaust volume is calculated according to the rules, and the tires are implemented according to the requirements of the event organizer. The use of related special devices and air pressure regulation systems is prohibited, and spare tires are prohibited on the car.

10. Ground clearance

• When there is no driver and the tire pressure is 1.6 bar, the parts of the car except the wheels and tires shall not be less than 60mm from the designated ground for vehicle inspection. The organizing committee may adjust the minimum ground clearance of different models during the interval between events to balance the performance. The car must meet the requirements during the entire event.

11. Brake system

• There are no restrictions on brake shoes, calipers, and discs. It is allowed to install front and rear brake pressure distribution brackets. There is no limit on the installation method of brake pipes. The original hand brake can be removed or replaced. The driver is restricted in the adjustment method of front and rear brake force distribution. The brake pipe must comply with relevant regulations. There are requirements for the installation position of the brake cooling pipe.

12. Body

• Appearance: The maximum width of the body is 1950mm. The original rearview mirror must be used. The whole car surround, rear wing, etc. are allowed to be installed, but there are size and shape restrictions. The body part can be modified, such as removing decorative strips, cutting tire chambers, etc.
• Cockpit: The co-pilot and rear seats need to be removed, the interior panels can be replaced with specific materials, the driving control components can be modified without restrictions but mass-produced parts must be used, and the steering wheel is not restricted but cannot have openings.
• Instrument panel: Modification is not limited but the installation cannot cause danger, and the original control switch can be changed.
• Engine compartment and luggage compartment: some sound insulation and decorative materials can be removed, unused batteries and spare tire racks can be removed (unwelded), and the rectifier under the original engine compartment can be removed or modified.

13. Electronic system

• The outer protective cover of the wiring harness must be made of flame-retardant material, the battery manufacturer and capacity are not limited, the installation method has requirements, and it is forbidden to use other devices for charging; the generator power can be replaced, and the drive wheel and belt are not limited; the original lighting system must be retained except for the fog lamp, and the headlights comply with regulations; fuses can be added and a power distribution control system can be used; the sensors used for data collection of the whole vehicle are not limited, but the sensors specified by the organizing committee must be installed.

14. Fuel supply system

• The fuel tank must be equipped with a leak-proof quick refueling interface, and a fuel tank certified by the International Automobile Federation must be used. The installation position is specified, and an auxiliary fuel tank with a maximum volume of 1 liter can be installed. There are detailed requirements for the installation and protection of the fuel tank.
• The fuel pipe must use aviation safety fuel pipes and be installed in accordance with regulations. One fuel supply pipe and one fuel return pipe are allowed; the number of fuel pumps is unlimited, and they must be protected against fire and leakage and separated from the cockpit.

15. Other regulations

• The use of ice or dry ice inside and outside the car is prohibited during the entire event. Drivers are allowed to use ice to cool down.
• Except for radio communication between the team and the driver, other methods of transmitting data from the sports vehicle are prohibited. The installation of an on-board data recording system is allowed. The timing pulse transmitter can be used but it must be disconnected from the engine control.