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monoxide, carbon dioxide, and oxides of shall be determined by the procedure nitrogen. A parallel sample of the dilu- outlined in Appendix B or other suittion air is similarly analyzed for hydro- able means. carbon, carbon monoxide, and oxides of (2) The road load power listed in the nitrogen.
table above shall be used or the vehicle (b) During dynamometer operation, a manufacturer may determine the road fixed speed cooling fan shall be posi load power by the following procedure tioned so as to direct cooling air to the and request its use: vehicle in an appropriate manner with (i) Measuring the absolute manifold the engine compartment cover open. The vacuum of a representative vehicle, of fan capacity shall normally not exceed the same equivalent inertia weight class, 5,300 c.f.m. If, however, the manufac
when operated on a level road under balturer can show that during field opera
anced wind conditions at a true speed of tion the vehicle receives additional cool- 50 m.p.h.. and ing, the fan capacity may be increased or (ii) Noting the dynamometer indiadditional fans used if approved in ad cated road load horsepower setting vance by the Administrator. In the case required to reproduce that manifold of vehicles with front engine compart vacuum, when the same vehicle is opments, the fan(s) shall be squarely po erated on the dynamometer at a true sitioned between 8 and 12 inches in front
speed of 50 m.p.h. The tests on the road of the cooling air inlets (grill). In the
and on the dynamometer shall be percase of vehicles with rear engine com formed with the same vehicle ambient partments (or if special designs make absolute pressure (usually baromet the above impractical), the cooling
i.e. within +5 mm. Hg. fan(s) shall be placed in a position to
(iii) The road load power shall be deprovide sufficient air to maintain engine
termined according to the procedure outcooling.
lined in Appendix B and adjusted accord(c) The vehicle shall be nearly level ing to the following if applicable. when tested in order to prevent abnor (3) Where it is expected that more mal fuel distribution.
than 33 percent of the vehicles in an (d) Flywheels, electrical or other engine family will be equipped with air means of simulating inertia as shown in conditioning, the road load power listed the following table shall be used. If the above or as determined in paragraph 2 equivalent inertia specified is not avail of this subsection shall be increased by able on the dynamometer being used, the 10 percent for testing all test vehicles next higher equivalent inertia (not to representing such engine family. exceed 250 lbs.) available shall be used. (f) The vehicle speed (m.p.h.) as Equivalent Road load
measured from the dynamometer rolls Loaded vehicle weight, inertia power @
shall be used for all conditions. A speed pounds
weight, 50 m.p.b., vs. time recording, as evidence of dynapounds horsepower
mometer test validity, shall be supplied Up to 1,125.
on request of the Administrator. 1,126 to 1,375...
(g) Practice runs over the prescribed 1,376 to 1,625.
1,500 1,626 to 1,875.
driving schedule may be performed to 1,876 to 2,125..
find the minimum throttle action to 2,126 to 2,375.
maintain the proper speed-time relation2,376 to 2,625 2,626 to 2,875.
ship. 2,876 to 3,250.
10.3 3,251 to 3,750..
NOTE: When using two-roll dynamometers 3,751 to 4,250.
12.0 a truer speed-time trace may be obtained by 4,251 to 4,750..
12.7 minimizing the rocking of the vehicle in 4.751 to 5,250.
the rolls. The rocking of the vehicle changes 5.251 to 5,750.
13.9 5,751 to above...
the tire rolling radius on each roll. The rock
ing may be minimized by restraining the (e) Power absorption unit adjustment. vehicle horizontally (or nearly so) by using
(1) The power absorption unit shall a cable and winch. be adjusted to reproduce road load power (h) The drive wheel tires may be inat 50 m.p.h. true speed. The indicated flated up to 45 p.s.i.g. in order to prevent road load power setting shall take into tire damage. The drive wheel tire presaccount the dynamometer friction. The sure shall be reported with the test relationship between road load (ab- results. sorbed) power and indicated road load (i) If the dynamometer has not been power for a particular dynamometer operated during the 2-hour period im
mediately preceding the test it shall be sion vehicles as if the first gear did not warmed up for 15 minutes by operating exist. it at 30 m.p.h. using a nontest vehicle. S 85.79 Automatic transmissions. $ 85.77 Three-speed manual transmis (a) All test conditions shall be run sions.
with the transmission in “Drive" (highest (a) All test conditions except as noted
gear). Automatic stick-shift transmisshall be run in highest gear.
sions may be shifted as manual transmis(b) Cars equipped with free wheeling
sions at the option of the manufacturer. or overdrive units shall be tested with
(b) Idle modes shall be run with the this unit (free wheeling or overdrive)
transmission in “Drive" and the wheels locked out of operation.
braked (except first idle; see $ 85.80). (c) Idle shall be run with transmis
(c) The vehicle shall be driven with sion in gear and with clutch disengaged
minimum throttle movement to main(except first idle; see § 85.80).
tain the desired speed.
(d) Acceleration modes shall be driven (d) The vehicle shall be driven with
smoothly allowing the transmission to minimum throttle movement to maintain the desired speed.
shift automatically through the normal (e) Acceleration modes shall be driven
sequence of gears. If the vehicle cannot
accelerate at the specified rates, the smoothly with the shift speeds as recom
vehicle shall be accelerated at WoT until mended by the manufacturer. If the
the vehicle speed reaches the speed at manufacturer does not recommend shift
which it should be at that time during speeds, the vehicle shall be shifted from
the driving schedule. first to second gear at 15 m.p.h. and
(e) The deceleration modes shall be from second to third gear at 25 m.p.h.
run in gear using brakes or throttle as The operator shall release the accelerator
necessary to maintain the desired speed. pedal during the shift, and accomplish the shift with minimum closed throttle § 85.80 Engine starting and restarting. time. If the vehicle cannot accelerate at (a) The engine shall be started acthe specified rates, the vehicle shall be cording to the manufacturer's recomaccelerated at WOT until the vehicle mended starting procedures. The initial speed reaches the speed at which it 20-second-idle period shall begin when should be at that time during the test. the engine starts.
(f) The deceleration modes shall be (b) Choke operation: run with clutch engaged and without (1) Vehicles equipped with automatic shifting gears from the previous mode, chokes shall be operated according to the using brakes or throttle as necessary to manufacturer's operating or owner's maintain the desired speed. For those manual including choke setting and modes which decelerate to zero, the “kick-down” from cold fast idle. If choke clutch shall be depressed when the speed "kick-down” time is not specified, it shall drops below 15 m.p.h., when engine
be performed 13 seconds after the enroughness is evident, or when engine
gine starts. The transmission shall be stalling is imminent.
placed in gear 15 seconds after the engine (g) Downshifting is allowed at the be is started. If necessary, braking may be ginning of or during a power mode if employed to keep the drive wheels from recommended by the manufacturer or if
turning. the engine obviously is lugging.
(2) Vehicles equipped with manual 8 85.78 Four-speed and five-speed man
chokes shall be operated according to
the instructions which will be included ual transmissions.
in the manufacturer's operating or own(a) Use the same procedure as for er's manual. If not specified, the choke three-speed manual transmissions for shall be operated to maintain engine idle shifting from first to second gear and at 1,100+50 r.p.m. during the initial from second to third gear. If the manu idle period and used where necessary facturer does not recommend shift during the remainder of the test to keep speeds, the vehicle shall be shifted from the engine running. third to fourth gear at 40 m.p.h. Fifth (c) The operator may use more choke, gear may be used at the manufacturer's more throttle, etc., where necessary to option.
keep the engine running. (b) If transmission ratio in first gear (d) If the vehicle does not start after exceeds 5:1, follow the procedure for 10 seconds of cranking, cranking shall three- or four-speed manual transmis- cease and the reason for failure to
start determined. The revolution counter on the constant volume sampler (see $ 85.85, Dynamometer test runs) shall be turned off and the sample solenoid valves placed in the “dump” position during this diagnostic period. In addition, either the positive displacement pump should be turned off or the exhaust tube disconnected from the tailpipe during the diagnostic period. If failure to start is an operational error, the vehicle shall be rescheduled for testing from a cold start. If failure to start is caused by vehicle malfunction, corrective action of less than 30 minutes duration may be taken and the test continued. The sampling system shall be reactivated at the same time cranking is started. When the engine starts, the driving schedule timing sequence shall begin. If failure to start is caused by vehicle malfunction and the vehicle cannot be started, the test shall be voided, the vehicle removed from the dynamometer, corrective action taken, and the vehicle rescheduled for test. The reason for the malfunction (if determined) and the corrective action taken shall be reported.
(e) If the engine “false starts”, the operator shall repeat the recommended starting procedure (such as resetting the choke, etc.).
(1) If the engine stalls during an idle period, the engine shall be restarted immediately and the test continued. If the engine cannot be started soon enough to allow the vehicle to follow the next acceleration as prescribed, the driving schedule indicator shall be stopped. When the vehicle restarts the driving schedule indicator shall be reactivated.
(2) If the engine stalls during some operating mode other than idle, the driving schedule indicator shall be stopped, the vehicle restarted, accelerated to the speed required at that point in the driving schedule and the test continued.
(3) If the vehicle will not restart within 1 minute, the test shall be voided, the vehicle removed from the dynamometer, corective action taken, and the vehicle rescheduled for test. The reason for the malfunction (if determined) and the corerctive action taken shall be reported. & 85.81 Sampling and analytical system
(exhaust emissions). (a) Schematic drawings. The following figures (Figs. la and lb) are sche
matic drawings of the exhaust gas sam-pling and analytical systems which will be used for testing under the regulations in this part. Additional components such as instruments, valves, solenoids, pumps, and switches may be used to provide additional information and coordinate the functions of the component systems.
(b) Component description (exhaust gas sampling system). The following components will be used in the exhaust gas sampling system for testing under the regulations in this part. See Figure 18. Other types of constant volume samplers may be used if shown to yield equivalent results.
(1) A dilution air filter assembly consisting of a particulate (paper) filter to remove solid matter from the dilution air and thus increase the life of the charcoal filter; a charcoal filter to reduce and stabilize the background hydrocarbon level; and a second particulate filter to remove charcoal particles from the air stream. The filters shall be of sufficient capacity and the duct which carries the dilution air to the point where the exhaust gas is added shall be of sufficient size so that the pressure at the mixing point is less than 1 inch of water pressure below ambient when the constant volume sampler is operating at its maximum flow rate.
(2) A flexible, leak-tight connector and tube to the vehicle tailpipe. The flexible tubing shall be sized and connected in such a manner that the static pressure variations in the vehicle tailpipe(s) remain within +1 inch of water of the static pressure variations measured during a dynamometer driving cycle with no connections to the tailpipe(s).
(3) A heating system to preheat the heat exchanger to within +10° F. of its operating temperature before the test begins.
(4) A heat exchanger capable of limiting the gas mixture temperature variation during the entire test to +10° F. as measured at a point immediately ahead of the positive displacement pump.
(5) A positive displacement pump to pumps dilute exhaust mixture. The pump capacity (300 to 350 c.f.m. is sufficient for testing most vehicles) shall be large enough to virtually eliminate water condensation in the system. See Appendix C for flow calibration techniques.
(6) Temperature sensor (Tl) with an accuracy of +2° F. to allow continuous recording of the temperature of the
dilute exhaust mixture entering the posi- oxide and carbon dioxide concentratiors tive displacement pump. (See § 85.83) by nondispersive infrared (NDIR) analy(1).)
sis and the determination of oxides of (7) Gauge (G1) with an accuracy of
nitrogen concentrations by chemilumi+3 mm. Hg to measure the pressure
nescence (CL) analysis in dilute exhaust depression of the dilute exhaust mixture
samples. The chemiluminescence method entering the positive displacement pump, relative to atmospheric pressure.
of analysis requires that the nitrogen (8) Gauge (G2) with an accuracy of
dioxide present in the sample be con53 mm. Hg to measure the pressure in verted to nitric oxide before analysis. See crease across the positive displacement Appendix E. Other types of analyzers pump.
may be used if shown to yield equivalent (9) Sample probes (Si and S2) results and if approved in advance by the pointed upstream to collect samples from Administrator. See Figure lb. the dilution air stream and the dilute (1) Quick-connect leak-tight fitting exhaust mixture. Additional sample (C4) to attach sample bags to analytical probes may be used, for example, to ob- system. tain continuous concentration traces of (2) Filter (F3) to remove any residual the dilute exhaust stream. In such case particulate matter from the collected the sample flow rate, in standard cubic sample. feet per test phase, must be added to (3) Pump (P3) to transfer samples the calculated dilute exhaust volume. from the sample bags to the analyzers. The position of the sample probe in Fig (4) Selector valves (V4, V5, V6, 17, ure la is pictorial only.
and V8) for directing samples, span (10) Filters (Fi and F2) to remove gases or zeroing gases to the analyzers. particulate matter from dilution air and (5) Flow control valves (N3, N4, N5, dilute exhaust samples prior to entering N6, N7, N8, N9, N10, N11, N12, and N13) sample collection bags.
to regulate the gas flow rates. (11) Pumps (P1 and P2) to pump the (6) Flowmeters (FL3, FL4, and FL5) dilution air and dilute exhaust into their to indicate gas flow rates. respective sample collection bags.
(7) Manifold (M1) to collect the ex(12) Flow control valves (N1 and N2) pelled gases from the analyzers. to regulate flows to sample collection (8) Pump (P4) to transfer expelled bags, at constant flow rates. The mini- gases from the collection manifold to a mum sample flow rate shall be 10 c.f.h. vent external to the test room (optional).
(13) Flowmeters (FL1 and FL2) to (9) Analyzers to determine hydroinsure, by visual observation, that con carbon, carbon monoxide, carbon dioxide stant flow rates are maintained through and oxides of nitrogen concentrations. out the test.
(10) An oxides of nitrogen converter (14) Three-way solenoid valves (V1, to convert any NO2 present in the V2, and V3) to direct sample streams to samples to NO before analysis. either their respective bags or overboard. (11) Selector valves (V9 and v10) to
(15) Quick-connect leak-tight fittings allow the sample, span, calibrating or (C1, C2, and C3), with automatic shut zeroing gases to bypass the converter. off on bag side, to attach sample bags (12) Water trap (Ti) to partially reto sample system.
move water and a valve (V11) to allow (16) Sample collection bags for dilu the trap to be drained. tion air and exhaust samples of sufficient (13) Sample conditioning columns to capacity so as not to impede sample remove remainder of water (WR1 and flow.
WR2 containing indicating CaSO4) and (17) Revolution counters to count the carbon dioxide (CDR1 and CDR2 conrevolutions of the positive displacement taining ascarite) from the co analysis pump while each test phase is in progress stream. and samples are being collected
(14) Selector valves (V12 and V13) to (c) Component description (exhaust permit switching from exhausted absorbgas analytical system). The following ing columns to fresh columns. components will be used in the exhaust (15) Water bubbler (W1) to allow gas analytical system for testing under saturation of the CO2 span gas to check the regulations in this part. The analyt efficiency of absorbing columns. ical system provides for the determina (16) Recorders (R1, R2, R3, and R4) tion of hydrocarbon concentrations by to provide permanent records of calibraflame ionization detector (FID) analy- tion, spanning and sample measuresis, the determination of carbon mon- ments.