GEN4 Radiator – 2026 & Up | Micro Sprint – Cross Flow

2026 GEN4 Radiator

Our updated 2026 GEN4 Radiator was designed to improve airflow, cooling efficiency, durability, and overall reliability.

The GEN4 design significantly increases airflow to the underside of the radiator while introducing a triangulated mounting system that eliminates the traditional radiator brackets most prone to cracking and failure. The result is a stronger, more secure mounting design built to withstand the demands of racing.

A cross-flow radiator design helps maintain consistent pressure on the return side of the engine water pump. Because coolant returns from the lowest point of the radiator, the system is less susceptible to introducing air pockets caused by a loss of coolant or inconsistent flow. As with any cooling system, all trapped air should be properly removed before racing. See our air-removal tips below for the recommended procedure.

Another major improvement is the additional open space above the radiator and beneath the hood. When paired with the GEN4 body design, this provides a cleaner path for hot air to escape instead of becoming trapped around the radiator.

The GEN4 radiator also features integrated fan mounting brackets and accommodates a larger cooling fan capable of moving nearly 1,300 CFM—almost double the airflow of the 12-inch fan previously used with our GEN3 radiator.

GEN4 Improvements

• Increased airflow underneath the radiator
• Triangulated mounting design for improved strength and durability
• Eliminates failure-prone traditional radiator brackets
• Cross-flow design for more consistent coolant circulation
• Low-mounted return helps reduce the potential for air entering the cooling system
• Increased open space above the radiator for improved hot-air evacuation
• Integrated fan mounting brackets
• Larger fan producing nearly 1,300 CFM  (Guhl relay system requires a 30AMP fuse over the stand 20AMP fuse for the fan to operate correctly)
• Nearly 2X the fan airflow compared with the previous GEN3 setup

FITS Late 2025 and Up GEN4 D1 Chassis: (Chassis updates are required for this radiator to be a direct fit)

Tips for Removing Air Pockets

• Reverse-fill the system: After installing all coolant lines, remove the thermostat and backfill the cooling system from the engine. This helps ensure the engine block is completely filled with coolant before starting.
• Use a radiator fill funnel: A radiator fill funnel makes it easier to keep the system topped off while air works its way out.  (find it here on Amazon)
• Confirm the system is completely full: If you’ve added less than 1 gallon of coolant, there is likely still an air pocket somewhere in the system.

• Burp the cooling system: Most thermostats do not fully open until approximately 190°F. Run the engine until it reaches 190–200°F. When the thermostat opens, you should see:

  • A temperature drop of approximately 30–40°F
  • The coolant level in the radiator/funnel drop

  Top the system back off with coolant and repeat this process 3–4 times to help remove trapped air.

• Bleed the system: Slightly crack open the -12AN fitting on the return line. Once you have a steady, consistent flow of coolant with no air coming from the fitting, the air has been removed from that portion of the system.
• Leave the fill funnel installed overnight: Keep coolant in the funnel overnight. If any remaining air pockets work their way to the top of the system, the coolant level in the funnel will drop as coolant replaces the trapped air.