A chassis dyno, also called a rolling road, works by using rollers to simulate road conditions in a controlled environment, allowing for various vehicle testing.
Understanding the Basics
A chassis dynamometer, commonly referred to as a "dyno," is a device that allows for the measurement of a vehicle's power and torque without actually driving on a road. It does this through a carefully engineered setup. Let's break down how it works:
Core Components
- Roller Assembly: The heart of the dyno is one or more large, heavy rollers. The vehicle's driving wheels are placed on these rollers. The rollers are usually quite substantial to handle the vehicle's weight and the forces exerted during testing.
- Resistance Unit: This unit is connected to the rollers and provides controlled resistance to simulate the forces the car would experience on the road, such as wind resistance and rolling friction. This resistance is crucial for accurate measurements.
- Measurement Sensors: These sensors are located throughout the dyno and measure the force applied to the rollers by the car's wheels. This allows engineers to calculate horsepower and torque.
Operational Process
Here's a step-by-step look at how a chassis dyno works:
- Vehicle Placement: The car is carefully driven onto the dyno, with its drive wheels positioned on the rollers. The car is securely strapped down to prevent movement during the test.
- Roller Rotation: As the vehicle's wheels spin, they cause the dyno's rollers to rotate.
- Resistance Application: The resistance unit applies a controlled force that opposes the roller's motion. This simulates real-world conditions, as if the car were experiencing resistance on a road.
- Data Collection: Measurement sensors track various parameters, including the speed of the rollers, the resistance force, and the rate of acceleration.
- Power & Torque Calculation: Using the collected data, the dyno calculates the engine's horsepower and torque, usually displayed in a graph.
What Makes it Useful?
Chassis dynos are incredibly useful for a variety of applications:
- Performance Tuning: Mechanics can adjust a vehicle's engine management system and other components, to achieve optimum power output.
- Diagnostic Testing: Identify mechanical or performance issues, by seeing how the vehicle performs under a simulated load.
- Emissions Testing: Dynos can assist in testing the emissions output of a car under simulated driving.
- Research and Development: Automakers use chassis dynos for research, development, and the testing of new models.
- Simulated Road Conditions: A chassis dynamometer is a mechanical device that uses one or more fixed roller assemblies to simulate different road conditions within a controlled environment, and is used for a wide variety of vehicle testing and development purposes.
Types of Chassis Dynos
There are two main types of chassis dynos:
- Inertia Dynos: These dynos use the mass of the rollers to apply resistance. They are simpler and less expensive but offer less precise control.
- Braked Dynos: These dynos use a braking mechanism to control the resistance, providing more accurate measurements and allowing for more complex testing scenarios.
