Modern dynamometers have revolutionized performance testing by replacing manual data recording with sophisticated, computerized systems. These systems acquire and store data, overcoming the limitations of traditional methods where observers had to manually transcribe readings, a task made even more challenging by the intense noise generated during testing.
A reliable data acquisition system with a fast sampling rate is crucial for accurate engine analysis. Ideally, the system should capture at least 100 samples per second (100Hz) from all sensor channels, with 200Hz or higher being preferable. This high sampling rate allows for the detection of subtle torque and RPM fluctuations between spark plug firings – rapid changes that are imperceptible during on-track or on-road driving. A sampling rate of 200 Hz ensures capturing the dynamic behavior of the engine.
However, lower sampling rates, such as 50Hz, can lead to inaccurate data representation as they only capture a single torque and RPM sample every other revolution. This can result in data synchronization with either plug firings or lower-power compression strokes, skewing the overall picture. Fast and reliable acquisition systems reading each cycle multiple times enable data averaging, mitigating these inaccuracies.
Averaging is a vital step in data acquisition, transforming raw data into meaningful insights. While experienced dynamometer operators can discern power curves from raw data, averaging helps inexperienced users by producing smoother, clearer graphs. The ability to average and dampen data streamlines analysis by reducing the volume of data points. For example, a 10-second dynamometer pull at 100Hz generates 1000 lines of data. Averaging eliminates transient noise and generates clear printouts, making it easier to identify performance trends and optimize engine tuning.