What Is a Chassis Dynamometer and How Do They Work?

A chassis dynamometer, also called a rolling pressure, is a machine that employs one or more fixed rigid roller assemblies to realistically simulate various road conditions in an ordered environment, and has been used for a multitude of automotive testing and performance improvement purposes. This type of dynamo is typically built around the vehicle’s chassis, which is a specially shaped steel shell whose upper edge is lower than its lower front edge. The lower edge is then stapled into the chassis, while the upper edge is then stapled into a rubber-backed foam. Alternatively, a rigid sleeve may be pressed into place around the drum, or alternatively the upper edge may be made stapled into the drum as well.

What is chassis dyno testing?

As the front wheel drive car rolls over the surface being tested, the weight of the dynamo is transmitted via a series of steel springs, and the dynamo is simulating the effects of hydrostatic pressure, roll speed, applied forces and other environmental factors. As the vehicle approaches the end of the distance travelled, the traction load is released, the roll rate starts to decelerate and the gap between the tyre and road surface starts to widen. As the tyre nears the Tyre wall, the air pressures begin to increase, the roll rate starts to increase again and the gap continues to widen until the tyre contact patch becomes full. At this point, the force required to bring the car back to a straight position from the stationary position requires a different kind of force to overcome.

The main advantage of a chassis dynamometer compared to other tests is that it accurately measures the forces needed to bring the vehicle to a straight and comfortable position and to indicate the tyre conditions that are required for maximum performance. There are many advantages to be gained from the use of a dynamometer in the racecar world, particularly where precision is essential. Every single corner on the car needs to be measured precisely to allow the engineers to fine-tuned each area to the smallest detail. It is also necessary to know exactly how a car is performing along the stretch. A good quality racing team uses a dedicated engineer who knows exactly what is happening all through the race, not just during the race. A chassis dynamometer will help the team improve its race performance.