(1) To estimate the flow-weighted mean raw exhaust NOX concentration from a turbocharged heavy-duty compression-ignition engine at a NOX standard of 2.5 g/(kW · hr), you may do the following:

(i) Based on your engine design, approximate a map of maximum torque versus speed and use it with the applicable normalized duty cycle in the standard-setting part to generate a reference duty cycle as described in § 1065.610. Calculate the total reference work, Wref, as described in § 1065.650. Divide the reference work by the duty cycle's time interval, Δtdutycycle, to determine mean reference power, Pref.

(ii) Based on your engine design, estimate maximum power, Pmax, the design speed at maximum power, fnmax, the design maximum intake manifold boost pressure, pinmax, and temperature, Tinmax. Also, estimate a mean fraction of power that is lost due to friction and pumping, p frict. Use this information along with the engine displacement volume, Vdisp, an approximate volumetric efficiency, hV, and the number of engine strokes per power stroke (two-stroke or four-stroke), Nstroke, to estimate the maximum raw exhaust molar flow rate, n exhmax.

(iii) Use your estimated values as described in the following example calculation:

(2) To estimate the flow-weighted mean NMHC concentration in a CVS from a naturally aspirated nonroad spark-ignition engine at an NMHC standard of 0.5 g/(kW · hr), you may do the following:

(i) Based on your engine design, approximate a map of maximum torque versus speed and use it with the applicable normalized duty cycle in the standard-setting part to generate a reference duty cycle as described in § 1065.610. Calculate the total reference work, Wref, as described in § 1065.650.

(ii) Multiply your CVS total molar flow rate by the time interval of the duty cycle, Δtdutycycle. The result is the total diluted exhaust flow of the ndexh.

(iii) Use your estimated values as described in the following example calculation:

(1) To estimate the flow-weighted mean raw exhaust NOX concentration from a turbocharged heavy-duty compression-ignition engine at a NOX standard of 2.5 g/(kW · hr), you may do the following:

(i) Based on your engine design, approximate a map of maximum torque versus speed and use it with the applicable normalized duty cycle in the standard-setting part to generate a reference duty cycle as described in § 1065.610. Calculate the total reference work, Wref, as described in § 1065.650. Divide the reference work by the duty cycle's time interval, Δtdutycycle, to determine mean reference power, Pref.

(ii) Based on your engine design, estimate maximum power, Pmax, the design speed at maximum power, fnmax, the design maximum intake manifold boost pressure, pinmax, and temperature, Tinmax. Also, estimate a mean fraction of power that is lost due to friction and pumping, p frict. Use this information along with the engine displacement volume, Vdisp, an approximate volumetric efficiency, hV, and the number of engine strokes per power stroke (two-stroke or four-stroke), Nstroke, to estimate the maximum raw exhaust molar flow rate, n exhmax.

(iii) Use your estimated values as described in the following example calculation:

(2) To estimate the flow-weighted mean NMHC concentration in a CVS from a naturally aspirated nonroad spark-ignition engine at an NMHC standard of 0.5 g/(kW · hr), you may do the following:

(i) Based on your engine design, approximate a map of maximum torque versus speed and use it with the applicable normalized duty cycle in the standard-setting part to generate a reference duty cycle as described in § 1065.610. Calculate the total reference work, Wref, as described in § 1065.650.

(ii) Multiply your CVS total molar flow rate by the time interval of the duty cycle, Δtdutycycle. The result is the total diluted exhaust flow of the ndexh.

(iii) Use your estimated values as described in the following example calculation: