dyno sample rate

would you happen to know a good rate to use for the torque graph my dyno has 2 settings finding it hard to get a smooth steady graph it can move to quick and be all over the place thanks

Hi dave what dyno do you have ?

normally the slower the the sample rate the smoother it is

This is a shot of my settings adjustable

It looks to me like the "MaxT" setting just controls the length of the X axis (time). The "AVG Samples" setting is a relatively crude smoothing filter that will average for example 50 consecutive measurements to make a single point on the graph. Most good dynos would have some other more advanced filtering tools to also detect and discard erroneous samples before the averaging operation such as large short spikes etc which can have a big impact on the averaging alone option.

If that averaging setting is your only option then you can only increase the averaging samples to smooth things out but the compromise is you will also lose detail and possibly real data at the same time.

There are many causes of torque "noise" on a chassis dyno so the first thing I would do in your case is set the averaging to zero so you can see how bad the data is and possibly identify what is causing the issue rather than just trying to filter it out. For example roller imbalance, absorber runout, erratic speed sensor or toothed wheel accuracy, erratic inertial torque calculation from a noisy RPM input etc.