Does the Noise Rejection feature cause serious phase shifting of data?
It is doubtful that noise rejection itself could cause any phase shift. An observed phase shift is more likely caused by too high a smoothing value for the data set. You can prove this by setting the smoothing value to zero. However, a phase shift could be caused by a test that idles before actually starting to accelerate. Removing some data lines at the beginning of the test using the SFBrowser tool can help achieve the correct results. Another problem can be that the noise rejection “noise threshold” was set too high for the data set. The default noise threshold was 60%. The noise threshold is another ProFilter parameter accessible through the Pro Filter setup window. Pro Filter will not work on chassis dynos if a “gear shift” occurs when running an acceleration test. This makes the feature unusable for vehicles equipped with automatic transmissions that are notorious for shifting during the acceleration run.
