[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.160-00]
[Page 570-573]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 86_CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND
ENGINES--Table of Contents
Subpart B_Emission Regulations for 1977 and Later Model Year New Light-
Sec. 86.160-00 Exhaust emission test procedure for SC03 emissions.
(a) Overview. The dynamometer operation consists of a single, 594
second test on the SCO3 driving schedule, as described in appendix I,
paragraph (h), of this part. The vehicle is preconditioned, in
accordance with Sec. 86.132-00 of this subpart, to bring the vehicle to
a warmed-up stabilized condition. This preconditioning is followed by a
10 minute vehicle soak (engine off) that proceeds directly into the SC03
driving schedule, during which continuous proportional samples of
gaseous emissions are collected for analysis. The entire test, including
the preconditioning driving, vehicle soak, and SC03 official test cycle,
is either conducted in an environmental test facility or under test
conditions that simulates testing in an environmental test cell (see
Sec. 86.162-00 (a) for a discussion of simulation procedure approvals).
The environmental test facility must be capable of providing the
following nominal ambient test conditions of: 95 [deg]F air temperature,
100 grains of water/pound of dry air (approximately 40 percent relative
humidity), a solar heat load intensity of 850 W/m2, and
vehicle cooling air flow proportional to vehicle speed. Section 86.161-
00 discusses the minimum facility requirements and corresponding control
tolerances for air conditioning ambient test conditions. The vehicle's
air conditioner is operated or appropriately simulated for the duration
of the test procedure (except for the vehicle 10 minute soak), including
the preconditioning. For gasoline-fueled Otto-cycle vehicles, the
composite samples collected in bags are analyzed for THC, CO,
CO2, CH4, and NOX. For petroleum-fueled
diesel-cycle vehicles, THC is sampled and analyzed continuously
according to the provisions of Sec. 86.110. Parallel bag samples of
dilution air are analyzed for THC, CO, CO2, CH4,
and NOX.
(b) Dynamometer activities. (1) All official air conditioning tests
shall be run
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on a large single roll electric dynamometer or an equivalent dynamometer
configuration that satisfies the requirements of Sec. 86.108-00.
(2) Position (vehicle can be driven) the test vehicle on the
dynamometer and restrain.
(3) Required SC03 schedule test dynamometer inertia weight class
selections are determined by the test vehicles test weight basis and
corresponding equivalent weight as listed in the tabular information of
Sec. 86.129-00(a) and discussed in Sec. 86.129-00 (e) and (f).
(4) Set the dynamometer test inertia weight and roadload horsepower
requirements for the test vehicle (see Sec. 86.129-00 (e) and (f)). The
dynamometer's horsepower adjustment settings shall be set such that the
force imposed during dynamometer operation matches actual road load
force at all speeds.
(5) The vehicle speed as measured from the dynamometer rolls shall
be used. A speed vs. time recording, as evidence of dynamometer test
validity, shall be supplied at request of the Administrator.
(6) The drive wheel tires may be inflated up to a gauge pressure of
45 psi (310 kPa), or the manufacturer's recommended pressure if higher
than 45 psi, in order to prevent tire damage. The drive wheel tire
pressure shall be reported with the test results.
(7) The driving distance, as measured by counting the number of
dynamometer roll or shaft revolutions, shall be determined for the test.
(8) Four-wheel drive vehicles will be tested in a two-wheel drive
mode of operation. Full-time four-wheel drive vehicles will have one set
of drive wheels temporarily disengaged by the vehicle manufacturer.
Four-wheel drive vehicles which can be manually shifted to a two-wheel
mode will be tested in the normal on-highway two-wheel drive mode of
operation.
(c) Vehicle and test activities for testing in a full environmental
cell. The SFTP air conditioning test in an environmental test cell is
composed of the following sequence of activities. Alternative procedures
which appropriately simulate full environmental cell testing may be
approved under the provisions of Sec. Sec. 86.162-00(a) and 86.163-00.
(1) Drain and fill the vehicle's fuel tank to 40 percent capacity
with test fuel. If a vehicle has gone through the drain and fuel
sequence less than 72 hours previously and has remained under laboratory
ambient temperature conditions, this drain and fill operation can be
omitted (see Sec. 86.132-00(c)(2)(ii)).
(2)(i) Position the variable speed cooling fan in front of the test
vehicle with the vehicle's hood down. This air flow should provide
representative cooling at the front of the test vehicle (air
conditioning condenser and engine) during the SC03 driving schedule. See
Sec. 86.161-00(e) for a discussion of cooling fan specifications.
(ii) In the case of vehicles with rear engine compartments (or if
this front location provides inadequate engine cooling), an additional
cooling fan shall be placed in a position to provide sufficient air to
maintain vehicle cooling. The fan capacity shall normally not exceed
5300 cfm (2.50 m3/s). If, however, it can be demonstrated
that during road operation the vehicle receives additional cooling, and
that such additional cooling is needed to provide a representative test,
the fan capacity may be increased or additional fans used if approved in
advance by the Administrator.
(3) Close all vehicle windows.
(4) Connect the emission test sampling system to the vehicle's
exhaust tail pipe(s).
(5)(i) Set the environmental test cell ambient test conditions to
the conditions defined in Sec. 86.161-00.
(ii) Turn on the solar heating system.
(iii) All vehicle test phases of preconditioning, soak, and the
official SC03 test cycle are to be performed in this set of ambient test
conditions.
(6) Set the air conditioning system controls as follows:
(i) A/C mode setting at Maximum.
(ii) Airflow setting at Recirculate, if so equipped.
(iii) Fan setting at Highest setting.
(iv) A/C Temperature setting at full cool (for automatic systems set
at 72 [deg]F).
(v) Air conditioning controls should be placed in the ``on''
position prior to
[[Page 572]]
vehicle starting so that the air conditioning system is active whenever
the engine is running.
(7) Start the vehicle (with air conditioning system on) and conduct
a preconditioning cycle as discussed in Sec. 86.132-00(o)(1).
(i) If engine stalling should occur during any air conditioning test
cycle operation, follow the provisions of Sec. 86.136-90 (Engine
starting and restarting).
(ii) For manual transmission vehicles, the vehicle shall be shifted
according the provisions of Sec. 86.128-00.
(8) Following the preconditioning cycle, the test vehicle (and
consequently the air conditioning system) and cooling fan(s) are turned
off and the vehicle is allowed to soak in the ambient conditions of
paragraph (c)(5) of this section for 10 1 minutes.
(9) Start engine (with air conditioning system also running).
Fifteen seconds after the engine starts, place vehicle in gear.
(10) Twenty seconds after the engine starts, begin the initial
vehicle acceleration of the driving schedule.
(11) Operate the vehicle according to the SC03 driving schedule, as
described in appendix I, paragraph (h), of this part.
(12) Turn the engine off 2 seconds after the end of the last
deceleration.
(d) Exhaust Emission Measurement Activities. The following
activities are performed, when applicable, in order to meet the timing
of the vehicle test and environmental facility activities.
(1) Perform the test bench sampling calibration sequence outlined in
Sec. 86.140-94 prior to or in conjunction with each series of exhaust
emission measurements.
(2) With the sample selector valves in the ``standby'' position,
connect evacuated sample collection bags to the dilute exhaust and
dilution air sample collection systems.
(3) Start the CVS (if not already on), the sample pumps, the
temperature recorder, the vehicle cooling fan, and the heated THC
analysis recorder (diesel-cycle only). The heat exchanger of the
constant volume sampler, if used, petroleum-fueled diesel-cycle THC
analyzer continuous sample line should be preheated to their respective
operating temperatures before the test begins.
(4) Adjust the sample flow rates to the desired flow rate and set
the gas flow measuring devices to zero.
(i) For gaseous bag samples (except THC samples), the minimum flow
rate is 0.17 cfm (0.08 liters/sec).
(ii) For THC samples, the minimum FID (or HFID in the case of
diesel-cycle vehicles) flow rate is 0.066 cfm (0.031 1/sec).
(iii) CFV sample flow rate is fixed by the venturi design.
(5) Attach the exhaust tube to the vehicle tailpipe(s).
(6) Start the gas flow measuring device, position the sample
selector valves to direct the sample flow into the exhaust sample bag,
the dilution air sample bag, turn on the petroleum-fueled diesel-cycle
THC analyzer system integrator, mark the recorder chart, and record both
gas meter or flow measurement instrument readings, if applicable.
(7) Start the engine (with air conditioning system also running).
Fifteen seconds after the engine starts, place vehicle in gear.
(8) Twenty seconds after the engine starts, begin the initial
vehicle acceleration of the driving schedule.
(9) Operate the vehicle according to the SC03 driving schedule.
(10) Turn the engine off 2 seconds after the end of the last
deceleration.
(11) Five seconds after the engine stops running, simultaneously
turn off gas flow measuring device No. 1 (and the petroleum-fueled
diesel hydrocarbon integrator No. 1 and mark the petroleum-fueled diesel
hydrocarbon recorder chart if applicable) and position the sample
selector valves to the ``standby'' position. Record the measured roll or
shaft revolutions and the No. 1 gas meter reading or flow measurement
instrument).
(12) As soon as possible, transfer the exhaust and dilution air bag
samples to the analytical system and process the samples according to
Sec. 86.140 obtaining a stabilized reading of the bag exhaust sample on
all analyzers within 20 minutes of the end of the sample collection
phase of the test.
(13) Immediately after the end of the sample period, turn off the
cooling fan,
[[Page 573]]
close the engine compartment cover, disconnect the exhaust tube from the
vehicle tailpipe(s), and drive the vehicle from dynamometer.
(14) The CVS or CFV may be turned off, if desired.
(e) NOX humidity correction. Calculated NOX
exhaust emissions from air conditioning tests conducted in an
environmental test cell at a nominal 100 grains of water/pound of dry
air are to be corrected for humidity to 100 grains of water/pound of dry
air (see the relationship of Sec. 86.164-00(d)).
[61 FR 54895, Oct. 22, 1996]