Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p9
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 9/71)
Character Range: 231688–234704

For test speed A: SVA = (Ymax1,A + Ymax2,A + Ymax3,A) / 3
              For test speed B: SVB = (Ymax1,B + Ymax2,B + Ymax3,B) / 3

              For test speed C: SVC = (Ymax1,C + Ymax2,C + Ymax3,C) / 3 where:
              Ymax1,  Ymax2,  Ymax3 = highest 1 s Bessel averaged smoke value at each of the three load steps The final value shall be calculated as follows:
                       SV = (0,43 x SVA) + (0,56 x SVB) + (0,01 x SVC)
Appendix 2

ETC TEST CYCLE

               1. ENGINE MAPPING PROCEDURE

1.1.                            Determination of the mapping speed range

              For generating the ETC on the test cell, the engine needs to be mapped prior to the test cycle for determining the speed vs torque curve. The minimum and maximum mapping speeds are defined as follows:

              Minimum mapping speed = idle speed

       Maximum mapping speed = nhi × 1,02 or speed where full load torque drops off to zero, whichever is
        lower

1.2.                            Performing the engine power map

              The engine shall be warmed up at maximum power in order to stabilise the engine parameters according to the recommendation of the manufacturer and good engineering practice. When the engine is stabilised, the engine map shall be performed as follows:

                (a)    the engine shall be unloaded and operated at idle speed;

                (b)    the engine shall be operated at full load setting of the injection pump at minimum mapping speed;

                (c)    the engine speed shall be increased at an average rate of 8 ± 1 min−1 /s from minimum to maximum mapping speed. Engine speed and torque points shall be recorded at a sample rate of a least one point per second.

1.3.                            Mapping curve generation

              All data points recorded under Section 1.2 shall be connected using linear interpolation between points. The resulting torque curve is the mapping curve and shall be used to convert the normalised torque values of the engine cycle into actual torque values for the test cycle, as described in Section 2.

1.4.                            Alternate mapping

              If a manufacturer believes that the above mapping techniques are unsafe or unrepresentative for any given engine, alternate mapping techniques may be used. These alternate techniques must satisfy the intent of      the specified mapping procedures to determine the maximum available torque  at  all  engine  speeds  achieved during the test cycles. Deviations from the mapping techniques specified in  this  section  for reasons of safety or representativeness shall be approved by the Technical Service along with  the  justification for their use. 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