Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p10
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 10/71)
Character Range: 234422–237665

In no case, however, shall descending continual sweeps of engine speed be used   for governed or turbocharged engines.

1.5.                            Replicate tests

              An engine need not be mapped before each and every test cycle. An engine shall be remapped prior to a test cycle if:

                —    an unreasonable amount of time has transpired since the last map, as determined by engineering judgement,

                or

                —    physical changes or recalibrations have been made to the engine which may potentially affect engine performance.

              2.                                GENERATION OF THE REFERENCE TEST CYCLE

              The transient test cycle is described in Appendix 3 to this Annex. The normalised values for torque and speed shall be changed to the actual values, as follows, resulting in the reference cycle.

2.1.                            Actual speed

              The speed shall be unnormalised using the following equation:

                                   Actual speed = % speed (reference speed – idle speed) + idle speed 100

              The reference speed (nref) corresponds to the 100 % speed values specified in the engine dynamometer schedule of Appendix 3. It is defined as follows (see Figure 1 of Annex I):
                              nref = nlo + 95 % × (nhi - nlo)

              where nhi and nlo are either specified according to Annex I, Section 2 or determined according to Annex III, Appendix 1, Section 1.1.

2.2.                            Actual torque

              The torque is normalised to the maximum torque at the respective speed. The torque values of the reference cycle shall be unnormalised, using the mapping curve determined according to Section 1.3, as follows:

              Actual torque = (% torque × max. torque/100) for the respective actual speed as determined in Section 2.1.
              The negative torque values of the motoring points ('m') shall take on, for purposes of reference cycle generation, unnormalised values determined in either of the following ways:

                —    negative 40 % of the positive torque available at the associated speed point,

                —    mapping of the negative torque required to motor the engine from minimum to maximum mapping speed,

                —    determination of the negative torque required to motor the engine at idle and reference speeds and linear interpolation between these two points.

2.3.                            Example of the unnormalisation procedure

              As an example, the following test point shall be unnormalised:

              % speed = 43

              % torque = 82

              Given the following values:

              reference speed =  2 200 min−1  idle speed = 600 min−1 results in,
                           actual speed = (43 × (2 200 − 600)/100) + 600 = 1 288 min−1 actual torque = (82 × 700/100) = 574 Nm
              where the maximum torque observed from the mapping curve at 1 288 min−1 is 700 Nm.

3.                                 EMISSIONS TEST RUN

              At the manufacturers request, a dummy test may be run for conditioning of the engine and exhaust system before the measurement