2025 China Endurance Championship (CEC) National Cup 1600-2000 Technical Regulations V1

The "2025 CEC National Cup 1600-2000 Technical Rules V1" was formulated by the China Automobile and Motorcycle Sports Federation. It specifies the various technical requirements and rules for the 1600 and 2000 groups of the China Endurance Championship National Cup. The following is a summary of the definitions, basic requirements for participating vehicles, modification specifications, safety standards, etc.:

I. Basic definitions and entry thresholds

1. Prototype vehicle definition

It must be a mass-produced passenger car with a production of at least 2,500 vehicles within 12 consecutive months.

2. Prohibited models

Formula, non-hardtop vehicles, assembled steel frame vehicles, and central steering wheel vehicles (unless approved by the organizing committee).

3. Basic vehicle structure

-Equipped with at least a driver's door and a co-pilot's door, and a four-wheel layout (front-wheel steering).

-Only a single internal combustion engine is allowed as a power unit, which must comply with the "2018 Domestic Automobile Competition Mass Production Vehicle Safety Modification Rules".

II. Core parameters of the vehicle and modification restrictions

1. Weight limit

• Balance requirements: Minimum weight must be achieved through a balance box, which is fixed to the bottom of the cockpit or luggage compartment, using ≥4 8.8-grade bolts (diameter ≥10mm), with a contact area ≥40cm².

2. Engine rules

• Intake and displacement: Naturally aspirated, up to 4 cylinders; 1600 group displacement ≤1600cc, 2000 group displacement ≤2000cc (K series over 2000cc requires special restrictions).
• Speed limit:
• 1600 group: Maximum 8500 rpm;
• 2000 group: ≤2000cc maximum 8300 rpm, >2000cc maximum 7700 rpm (the organizing committee can adjust).
• Air restrictor:
• 1600 group maximum inner diameter 50mm;
• 2000 group ordinary engine 70mm, K series high-performance engine 54mm (over 2000cc is 52mm).
• Modification prohibited: Do not modify the firewall, and do not use titanium/magnesium/ceramic materials (unless equipped by the original manufacturer).

3. Transmission system

• Transmission: Only manual transmission is allowed, and sequential transmission can be used (simulated sequential gear shifting is considered sequential), with a maximum of 6 forward gears and a reverse gear.
• Clutch: A maximum of 2 clutch plates, the outer diameter of the friction plate ≥183mm, and carbon materials are prohibited.
• Differential: Only mechanical differentials are allowed, and a lubricating oil cooling system can be installed on the rear drive.

III. Safety standards and mandatory configuration

1. Roll cage and seat

• Must comply with the "2018 Domestic Automobile Competition Mass Production Vehicle Safety Modification Rules", the seat must be FIA certified (8855-1999 or 8862-2009 standard), the mounting bracket material thickness ≥3mm (steel) or ≥5mm (aluminum).
• The seat belt must comply with FIA 8853-2016 and be equipped with a 5-point seat belt.

2. Fire extinguishing system

• A ≥2kg dry powder fire extinguisher (fire 3C certification) must be installed, and the FIA certified fire extinguishing system is recommended (Technical List N°16/52/97).

3. Protective net

• The driver's side window must be equipped with a protective net, the material is non-flammable, the mesh is 25×25mm-60×60mm, fixed to the roll cage and equipped with a one-hand release device (color code is orange/red).

4. Electrical and fuel safety

• The wiring harness must be made of flame-retardant materials, the battery must be fixed to a metal support, and the battery in the cockpit must be equipped with a ventilation pipe.
• The fuel tank must be FIA-certified (FT3/FT5, etc.), installed in the area behind the B-pillar of the roll cage, and the refueling port is located outside the car and does not protrude from the body.

Fourth, body and chassis modification specifications

1. Appearance restrictions

• The maximum width of the 1600 group is 1850mm, and the 2000 group is 1920mm; it is allowed to add surrounds and rear wings, but the height of the rear wing must not exceed the roof, the width must not exceed the body, and spoilers and spike structures are prohibited.
• The engine guard must be made of metal (thickness ≥5mm) and must not be used as an aerodynamic component.

2. Suspension and braking

• The suspension system can be modified, but the steering gear must use mass-produced parts, and the electronic power pump must not be installed in the cockpit.
• The brake system allows the replacement of calipers, discs, and plates, and the ABS system needs to be removed. The front and rear brake force distribution is only allowed to be adjusted by mechanical levers or spring preload distribution valves.

3. Wheels and tires

• 1600 sets of maximum 15-inch × 8J wheels (4/5 screws), 2000 sets of maximum 17-inch × 9J wheels (only 5 screws); spare tires and tire pressure adjustment systems are prohibited.

V. Other important rules

1. Data and communication
   Remote data transmission is prohibited. Only team and driver radio communication is allowed. The on-board data recording system cannot have an accelerometer.
2. Prohibited items
   It is prohibited to use ice cubes/dry ice to cool the vehicle (except for personal cooling by the driver).
3. Ground clearance
   When there is no driver and the tire pressure is 1.6bar, the minimum ground clearance is 80mm, which must be maintained throughout the journey.

VI. Reference standards and the authority of the organizing committee

• The core reference is the "2018 Domestic Automobile Competition Production Vehicle Safety Modification Rules". The organizing committee has the right to adjust parameters such as vehicle weight, speed, and restrictor size according to actual conditions, subject to the supplementary rules.
• All modifications must comply with the rules. Modifications that are not explicitly allowed are prohibited, and other restrictions cannot be circumvented through modifications.