Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p1
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 1/56)
Character Range: 298967–301866

13    0                  0                   210

Sum                                          1,895

7.3. General test sequence

 The following flow chart outlines the general guidance that should be followed during testing. The details of each step are described in the relevant paragraphs. Deviations from the guidance are permitted where appropriate, but the specific requirements of the relevant paragraphs are mandatory.

 For the WHTC, the test procedure consists of a cold start test following either natural or forced cool-down of the engine, a hot soak period and a hot start test.

 For the WHSC, the test procedure consists of a hot start test following engine preconditioning at WHSC mode 9.

7.4. Engine mapping and reference cycle

 Pre-test engine measurements, pre-test engine performance checks and pre-test system calibrations shall be made prior to the engine mapping procedure in line with the general test sequence shown in paragraph 7.3.

 As basis for WHTC and WHSC reference cycle generation, the engine shall be mapped under full load operation for determining the speed vs. maximum torque and speed vs. maximum power curves. The mapping curve shall be used for denormalizing engine speed (paragraph 7.4.6.) and engine torque (paragraph 7.4.7.).

7.4.1. Engine warm-up

 The engine shall be warmed up between 75 per cent and 100 per cent of its maximum power or according to the recommendation of the manufacturer and good engineering judgment. Towards the end of the warm up it shall be operated in order to stabilize the engine coolant and lube oil temperatures to within 2 per cent of its mean values for at least 2 minutes or until the engine thermostat controls engine temperature.

7.4.2. Determination of the mapping speed range

 The minimum and maximum mapping speeds are defined as follows:
                              Minimum mapping speed = idle speed
                              Maximum mapping speed = nhi x 1.02 or speed where full load torque drops off to zero, whichever is smaller.

7.4.3. Engine mapping curve

 When the engine is stabilized according to paragraph 7.4.1., the engine mapping shall be performed according to the following procedure.
(a) The engine shall be unloaded and operated at idle speed;
(b) The engine shall be operated with maximum operator demand 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, or at a constant rate such that it takes 4 to 6 minutes to sweep from minimum to maximum mapping speed. Engine speed and torque points shall be recorded at a sample rate of at least one point per second.

 When selecting option (b) in paragraph 7.4.7. for determining negative reference torque, the mapping curve may directly continue with minimum operator demand from maximum to minimum mapping speed.

7.4.4. Alternate mapping

 If