irregularities in crankshaft velocity introduced when measuring crankshaft rotation at a section of a crankshaft in an internal combustion engine that is less damped to torsional oscillations than is another more accessible crankshaft section are corrected using a narmax - generated model to predict rotation measurements that would have been obtained at the inaccessible section based on data actually collected at the accessible crankshaft section . thus , the effects of torsional oscillations in the crankshaft are substantially filtered away , resulting in crankshaft acceleration values that form the basis of a misfire detector having nearly maximum signal - to - noise performance .