Dynos measure torque through two primary methods: direct force absorption and calculation based on roller acceleration and RPM.
Direct Force Measurement
- Some dynos are designed to directly measure torque by absorbing the force that the vehicle applies.
- These types of dynos are equipped with mechanisms that physically resist the rotation of the engine, which is connected to the dyno.
- The force measured is directly proportional to the torque produced.
- These systems use load cells or other force transducers to convert the mechanical resistance into an electrical signal that can then be measured and displayed.
Calculating Torque Using Roller Acceleration and RPM
- Other dynos calculate torque indirectly by monitoring the speed of the roller and how quickly it accelerates.
- These systems use an RPM (Revolutions Per Minute) signal and measure the rate of acceleration of the dyno's roller.
- The dyno determines the vehicle's power by measuring how fast the roller spins and how quickly the speed changes.
- This data, along with the dyno's known inertia, can be used to calculate the torque exerted by the vehicle's engine.
- Formula: Torque (T) is derived from the relationship between power (P) and angular velocity (ω): T = P / ω, where power is calculated using the rate of acceleration and the moment of inertia of the rotating components on the dyno.
Table: Dyno Torque Measurement Methods
| Method | Measurement Technique | Data Used | Key Advantage |
|---|---|---|---|
| Direct Force Absorption | Mechanical resistance and force measurement | Force exerted on dyno | Direct reading of torque |
| Roller Acceleration & RPM Calculation | Speed and rate of acceleration tracking | RPM and roller acceleration rate | Uses calculated data to derive torque |
Practical Insights
- The type of dyno used can affect the measurement method and precision.
- Both methods provide a reliable assessment of an engine's torque output when properly calibrated and used.
- Understanding these methods can help in interpreting dyno results and making informed tuning decisions.
- For instance, you may see different torque measurements from various dynos depending on which method is being utilized.
