Aerodynamic Forces

Rules Changes…Again

NASCAR issues rules change on Wednesday – one of which extends an earlier rule change to try to improve aerodynamics at intermediate tracks. The other is designed to cut off an entirely new direction of research before it starts. […]

Michigan International Speedway

Michigan: Don’t Believe the Speeds

All the talk at Michigan about high speeds and the hoopla over passing the 200-mph barrier prompts me to offer this caveat: Take the speeds you hear with a grain of salt because the average lap speeds are estimates, not measurements. […]


Pocono: The Shifty Triangle

NASCAR engines like to run at about 8000-9500 rpm (revolutions per minute); however, the tires on the car rotate around 2400 rpm at 200 mph. The gearing in the transmission and the rear end gear reduce the rotational engine speed, with different gears providing different reductions. When you talk about the size of a gear, you’re actually talking about the relative sizes of a pair of gears. The gear on the left in the diagram has 20 teeth, while the gear on the right has 10 teeth, so this gear would be a 2:1, meaning that the smaller gear rotates twice every time the larger gear rotates once. […]