Dr. Diandra: Dishing the dirt on racing the Next Gen car at Bristol

Racing the Next Gen car at Bristol requires the most modifications of any track on the schedule.

Even the tires are different.

Here are three other ways the Next Gen car becomes a dirt car, just for this weekend.

The primary challenge of dirt racing is that it’s dirty.

The last place you want dirt is in a high-tech engine with the tightest of clearances. A throttle-body air filter is permitted at all tracks, but essential at Bristol.

The second-last place you want dirt is embedded in your radiator. Radiators use airflow to cool water coming from the engine. Without airflow, the engine could overheat.

The radiator air inlet sits in the center of each car’s front fascia. Although each manufacturer’s fascia styling is different, the openings are the same. The diagram below shows a Ford’s front fascia. Red indicates the areas where up to two 4”-diameter brake duct openings can be put on each side.

Teams place grates over the radiator air inlet openings at all tracks. When running the Next Gen at Bristol, they use an additional screen with a fine-mesh filter fabric placed not more than 2 inches in front of the usual screen. Air can flow into the radiator around the top, bottom and sides of the extended filter, while mud is captured. The mesh can be changed out as needed.

Stewart Haas Fords used white screens in 2022, making them the easiest cars on which to see the feature. Although the photo below makes it look like the extended screen is right in front of the fascia, there’s actually more than an inch between them.

The protrusion at the very bottom of the screen is a camera — this one with a rather large glob of dirt on it.

The photo below shows a Gen-6 Ford fitted out for dirt racing. The extended splitter of the Gen-6