40 CFR § 1036.510 - Transient testing.

§ 1036.510 Transient testing.

(a) Measure emissions by testing the engine or hybrid powertrain on a dynamometer with one of the following transient duty cycles to determine whether it meets the transient emission standards in subpart B of this part:

(1) For spark-ignition engines, use the transient duty cycle described in paragraph (a) of appendix B of this part.

(2) For compression-ignition engines, use the transient duty cycle described in paragraph (b) of appendix B of this part.

(3) For spark-ignition hybrid powertrains, use the transient duty cycle described in paragraph (a) of appendix B of this part.

(4) For compression-ignition hybrid powertrains, use the transient duty cycle described in paragraph (b) of appendix B of this part.

(b) Perform the following depending on if you are testing engines or hybrid powertrains:

(1) For engine testing, the transient duty cycles are based on normalized speed and torque values relative to certain maximum values. Denormalize torque as described in 40 CFR 1065.610(d). Denormalize speed as described in 40 CFR 1065.512.

(2) For hybrid powertrain testing, follow § 1036.505(b)(2) to carry out the test except replace Pcontrated with Prated, the peak rated power determined in § 1036.527, keep the transmission in drive for all idle segments after the initial idle segment, and for hybrid engines select the transmission from Table 1 of § 1036.540 substituting “engine” for “vehicle”. You may request to change the engine commanded torque at idle to better represent curb idle transmission torque (CITT).

(c) The transient test sequence consists of an initial run through the transient duty cycle from a cold start, 20 minutes with no engine operation, then a final run through of the same transient duty cycle. Emissions from engine starting is part of the both the cold and hot test intervals. Calculate the total emission mass of each constituent, m, and the total work, W, over each test interval according to 40 CFR 1065.650. Calculate the official transient emission result from the cold-start and hot-start test intervals using the following equation:

(d) Calculate cycle statistics and compare with the established criteria as specified in 40 CFR 1065.514 for engines and 40 CFR 1037.550 for hybrid powertrains to confirm that the test is valid.

[86 FR 34385, June 29, 2021]

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