73-16
Emissions from a Suzuki Fronts GX Equipped
with a Prototype 1975 Control Device
February 1973
Alan Whitmyer
Test and Evaluation Branch
Environmental Protection Agency
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Background
In late November 1972, U.S. Suzuki Corporation brought two
cars to the EPA facility in Ann Arbor for 1973 certification.
Suzuki requested that the Test and Evaluation Branch test one
of the cars with a device designed to make the car meet the
1975 standards. The device is designed to regulate the air/fuel
ratio during accelerations by applying a vacuum to the carburetor
float bowl. The length of time during which the vacuum is
applied is a function of the throttle opening. During cruise
tonditions the device has no effect.
Vehicle Description
The test vehicle is a 1973 Suzuki with a 360 cc (21.9 cu. in.)
two-stroke engine and a manual transmission (4-speed). The
engine is a water-cooled, 3-cylinder, in-line, two-stroke
located in the rear of the car. The car has a two-door body
with a seating capacity of four persons. It is a right-hand
drive vehicle. Weight is 1060 pounds.
Test Program
All tests were conducted as specified in the 1975 Federal Test
.Procedure (FTP). A Beckman 402 flame ionization detector was
used to continuously monitor hydrocarbon emissions. The sample
for the FID was taken immediately downstream of the dilution box.
A heated sample line was used and the sample was drawn through
a transverse probe located in the CVS duct. A total of four
tests were run on the car. Inertia weight was set at 1500 pounds.
In the first two tests conducted on the car, it became evident
that the car was causing a severe interference problem with the
.Beckman FID. Due to this interference we were unable to obtain
any useful information from the first two heated FID traces.
The third test was run with the hood on the engine compartment
closed. This eliminated the interference problem with the FID.
tAt this point, it became evident that the Beckman 402 was badly
in need of an overhaul. The remainder of the tests were conducted
with the FID built in-house by our laboratory personnel.
The final two tests were conducted with a moderate degree of
success. During one test the CVS unit did not begin sampling
until approximately 60 seconds into Bag 1. During the next test
no heated FID sample was taken for Bag 3.
Results
The emission data obtained is shown in Tables I and II. The
vehicle attained 1976 levels of NOx while failing to meet CO
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-2-
and HC requirements. A steady deterioration of CO, CC>2, and HC
occurred during the testing sequence. Due to problems with the
FID and CVS sampling, no single test had complete bag results
for both systems. The individual bag results are shown in
Table II.
Test #3 gave widely varying results, with bag 2 being much lower
for the heated FID and bag 3 results being much higher for the
FID. In test #4, the cold bag results were very close to the
hot FID results for bags 1 and 2.
Conclusions
Although NOx levels were well below 1976 standards, the vehicle
failed both HC and CO standards.
Due to a lack of valid tests, it is not possible to say
whether or not the heated FID gives results that are sub-
stantially different from the cold bag results. Because of
the electrical interference generated by the engine in this
car, it is necessary to shield electrical components being
operated in the test cell when the car is being run.
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TABLE I
SUZUKI FRONTS GX
Mass Emissions, Grams Per Mile
1975 Federal Test Procedure
HC HC CO NOx C02
Test No. cold bag hot cont.
16
16
16
16
-81
-89
-129
-133
1
0
-
. 1
.86
.74
.41
7
11
--invalid
14
.06
.00
.35
0.
0.
0.
22
21
-
21
372
381
391
.70
.12
-
.16
TABLE II
SUZUKI FRONTE GX
Hydrocarbon Mass Emissions, Grams Per Mile
1975 Federal Test Procedure
(individual bag data)
Bag 1 Bag 2 Bag 3
cold hot cold hot cold hot
Test # bag cont. bag cont. bag cont
16-
16-
•16-
16-
81
89
129
133
2
2
-
2
.84
.90
.13 2.14
0.
0.
0.
0.
15
05
23
08
.055
0.10
0.
0.
0.
3.
71
43
63
38
2.23
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