Evaluation of
The LaForce-Modified
AMC Hornet
December 1974
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Environmental Protection Agency
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Background
The Environmental Protection Agency receives information about many
systems which appear to offer potential for emission reduction or fuel
economy improvement compared to conventional engines and vehicles. EPA's
Emission Control Technology Division (ECTD) is interested in evaluating
all such systems, because of the obvious benefits to the Nation from
the identification of systems that can reduce emissions, improve economy,
or both. EPA invites developers of such systems to provide to the
EPA complete technical data on the system's principle of operation,
together with available test data on the system. In those cases in
which review by EPA technical staff suggests that the data available
show promise, attempts are made to schedule tests at EPA's Motor
Vehicle Emission Laboratory (MVEL) at Ann Arbor, Michigan. The results
of all such test projects are set forth in a series of Technology
Assessment and Evaluation Reports, of which this report is one.
The conclusions drawn from the EPA evaluation tests are necessarily
of limited applicability. A complete evaluation of the effectiveness
of an emission control system in achieving improvements on the many
different types of vehicles that are in actual use requires a much
larger sample of test vehicles than is economically feasible in the
evaluation test projects conducted by EPA. For promising systems it
is necessary that more extensive test programs be carried out.
The conclusions from the EPA evaluation tests can be considered
to be quantitatively valid only for the specific test car used.
However, it is reasonable to extrapolate the results from the EPA
tests to other types of vehicles in a directional or qualitative manner,
i.e., to suggest that similar results are likely to be achieved on
other types of vehicles.
This evaluation of a LaForce engine is the third opportunity that
personnel from EPA and its predecessor organizations in the U.S. Public
Health Service have had to examine and report on a LaForce engine.
The first occasion was in 1965, when automotive engineers from
the USPHS Division of Air Pollution (DAP) in Cincinnati, Ohio met with
LaForce, Inc. personnel in Pittsburgh, Pennsylvania and examined an
experimental carburetor and variable compression engine. Based on
their examination of hardware and available information, DAP personnel
recommended no further investigation or consideration of these
inventions by USPHS, citing the impracticality of the designs, the
crude state of their development, and the lack of substantiating
test data.
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In late 1971, a 1967 Ford Falcon with LaForce-modified carburetor,
exhaust manifold, ignition timing and valve timing was evaluated in
a test program conducted by EPA personnel at the Ann Arbor laboratory.
The car achieved the exhaust emission levels required by the 1973
standards. Compared to other systems, however, the LaForce modifications
were considered to be more extensive than necessary to attain the
required emission levels. It was also felt that many features in the
system were ineffective.
In late September 1974, EPA was approached by persons representing
Ventur-E, Inc., who proposed that EPA evaluate and test at the Agency's
Ann Arbor laboratory an engine modified and installed in a 1974 Hornet
by Edward P. LaForce and Robert C. LaForce. EPA engineers concluded
that the data submitted for review were not sufficient to justify an
evaluation, since the data were limited to a fuel economy value and
pollutant concentrations (not mass measurements) with the car running
at a constant 30 raph on a chassis dynamometer with no load programmed
into the dynamometer. Power output at the rear wheels was only that
required to deflect the tires and to overcome the small amount of
friction in the dynamometer rolls, a total of about 1 or 2 horsepower.
Ordinarily the dynamometer would be programmed with 11.2 hp at 50 mph
for the 1974 Hornet, the vehicle in which the LaForce engine was
installed. EPA's response, in a letter dated October 3, 1974, was
to urge Ventur-E to test the car by the 1975 Federal Test Procedure
(75 FTP) and also to provide to EPA more information on the road
tests that Ventur-E personnel were conducting for fuel economy. It
was explained that EPA would conduct tests at MVEL if substantiated
fuel economy data warranted it.
No data were forthcoming, but in late November members of the
U.S. Senate Committee on Public Works requested the EPA Administrator
to conduct a thorough evaluation of the LaForce engine at the
Ann Arbor laboratory, and tests of the LaForce engine as installed in
the 1974 Hornet were scheduled in response to that request.
On December 4, 1974, Ventur-E personnel delivered the LaForce
modified car and a standard 1974 Hornet with the same general
specifications to MVEL for the test program. In meetings the next
day EPA personnel discussed the test program and Ventur-E personnel
gave an informal discussion of the LaForce modifications. Checkout,
preparation and familiarization with the test vehicles were conducted
by EPA laboratory personnel with Ventur-E personnel present. Testing
began on December 6, 1974 and was completed on December 12, 1974.
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The following description of the LaForce engine and the claims
made for it is based upon a Ventur-E press release dated November 14,
1974; the statement of Edward P. LaForce, President of Ventur-E, Inc.,
to the U.S. Senate Committee on Commerce on November 26, 1974; and
the written notes of EPA personnel who were present at the meetings
mentioned above between EPA and Ventur-E personnel on December 5, 1974.
In the LaForce intake system the fuel - air charge from a con-
ventional carburetor is made to turn 180 , using "the centrifuge
principle to separate heavy and light elements in gasoline. The
volatile elements are delivered immediately through intake manifolds
to the cylinders. The less volatile elements are cycled through
heating chambers surrounding the exhaust manifolds and then
delivered back to a separator and recycled until they are volatile
enough for delivery to the cylinder."
A LaForce - designed camshaft "causes the inlet valves to close
much later on the compression stroke than in conventional engines."
The fuel - air charge in the cylinder is thus transferred from
cylinder to cylinder, providing even mixture distribution in all
cylinders. It is claimed that the delayed inlet valve closing also
results in better performance at high engine speed. The hydraulic
valve lifters in the stock engine have been replaced by solid
lifters.
Cylinder bore and stroke, pistons, and crankshaft are unchanged
from the stock engine.
The stock cylinder head has been milled, resulting in a smaller
combustion chamber and an expansion ratio that is "two to three
times greater in (the LaForce) engine than in conventional engines,"
which leads to higher efficiency. However because of the delayed
inlet valve closing, conventional compression pressures are
maintained.
The stock exhaust manifold has been divided into two separate
parts to permit alternating of exhaust discharges between them,
and modified to include the heating chambers for the intake system,
and a. dual exhaust system is employed.
The initial ignition timing was said to be advanced 4 over the
stock timing, with the vacuum advance reduced significantly. The
carburetor is essentially stock, but with a lower idle fuel flow
rate and a richening of the main jets. The crankcase ventilation
system is intact, although the evaporative control system has been
removed. Neither the standard 1974 Hornet nor the LaForce -
modified engine employs exhaust gas recirculation (EGR).
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Among the claims made by Ventur-E for the engine are these:
1) "... tests ... show substantially increased power."
2) "Road tests also point to improved performance over comparable
displacement engines."
3) "The LaForce engine, with its much higher efficiency, reduces
pollutants to what appears to be a negligible level."*
4) "The explanation for the improved efficiency of the LaForce
Engine is that we have discovered a way to achieve more complete
combustion of gasoline than the method used by the conventional
engine. Our research has shown that in the conventional engine
only about 3/4 of every gallon of gasoline is involved in the
effective combustion process. The remaining one quarter is
wasted. Not only is it wasted, but it is a major contributor
to our pollution problem. The LaForce engine effectively
utilizes this normally unused quarter of a gallon. In
addition, the engine utilizes the entire gallon more efficiently.
The result is greater mileage out of each gallon of gas. The
result, in addition, is decreased pollution."
Vehicle Description
Four cars were involved in the test program. The LaForce car was
basically a 1974 American Motors Corporation (AMC) Hornet, equipped
with a six-cylinder engine of 258 cubic inches displacement (CID) and
automatic transmission. Ventur-E personnel stated that they had made
extensive modifications to the induction and exhaust systems, cylinder
head, camshaft, and valve train of the basic engine. This car was
equipped with a rear axle having a gear ratio of 3.08:1.
Two standard, unmodified 1974 Hornets were also tested, the one
furnished by Ventur-E, another rented by EPA from a dealer in the
Ann Arbor - Detroit area. Both these cars were equipped with the
258 CID engine, automatic transmission, and rear axle having a gear
ratio of 2.73:1.
The fourth car, also rented by EPA from a local dealer, was a 1975
Hornet with 258 CID engine, automatic transmission and 2.73 rear axle.
The cars are described in detail in Tables A-l through A-4 in Appendix
A. Ignition timing and mixture settings are discussed below, under Test
Procedures.
Although this claim appears in Ventur-E press releases, no claims
for emission reductions were made to EPA personnel by Ventur-E
personnel in the meetings of December 5, 1974.
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LaForce Engine Concept Analysis
Although EPA has received no information quantifying or documenting
the modifications to the LaForce engine, EPA personnel judge that the
three effective changes to the engine are, in order of decreasing
importance, delaying the inlet valve closing, milling the cylinder
head, and separating liquid fuel from the fuel-air mixture.
Contrary to common belief, it is the expansion ratio of an
Otto cycle engine that determines its efficiency, not the compression
ratio. In a conventional engine, both expansion ratio and compression
ratio are equal and therefore expansion ratio increases (and consequently
efficiency) are limited by pre-ignition and detonation problems that
arise from the attendant higher compression ratio, and heat losses
from the mixture near the end of the compression stroke. It has been
found that an expansion ratio of about 12:1 is the highest that is
practical for a conventional, spark ignited engine.
If a technique could be found to increase the expansion ratio
without increasing the compression ratio then an increase in efficiency
would result without the combustion problems mentioned above. Over
the years several ideas and engine designs have been proposed, including
variable compression ratios, variable stroke, variable valve timing
and so on. All such approaches have been found to be bulky, complex,
costly, with reduced power output, or otherwise impractical.
With its smaller combustion chamber and delayed inlet valve
closing, the LaForce engine is the latest in this line to appear.
The combination of a delayed inlet valve closing and a reduced clearance
volume, achieved by milling the cylinder head, has resulted in an
increased expansion ratio with apparently little or no increase in
compression ratio. If the compression ratio remains the same as in
the standard Hornet engine, no increase in nitrogen oxides (NOx)
emissions would be expected.
Because part of the fuel-air charge is pushed back out of the
cylinder on the compression stroke, the LaForce engine would be
expected to have less power potential than the standard Hornet engine.
The effects of milling the head and delaying the inlet valve
closing may be better understood by referring to Figure 1 and Figure 2
which illustrate the events that occur during the compression stroke
in the standard engine and in the LaForce engine. The AMC combustion
chamber is known to have a wedge shape and is suitably depicted.
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5a
Piston
"\
Swept
Volume
Connecting Rod
BDC
Clearance Volume
TDC
Figure 1. Standard Engine
Effective
I Swept
Volume
Swept
Volume
BDC
Inlet Valve
Closes
Clearance
Volume
TDC
Figure 2. LaForce Engine
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In the standard engine (Figure 1) the inlet valve closes near bottom
dead center (BDC). As the crankshaft rotates, the connecting rod pushes
the piston up, compressing the fuel air charge. Near top dead center
(TDC) the spark plug ignites the mixture and the piston starts downward
on its expansion, or power-producing, stroke. In the standard engine
the expansion ratio and the compression ratio are both 8:1. Swept
Volume is the volume displaced by the piston as it moves from BDC
to TDC. Clearance Volume is the volume above the piston at TDC. In
a standard engine the relationship between compression ratio (C.R.)
and expansion ratio (E.R.) is thus:
C.R. = E.R. = (Clearance Volume + Swept Volume) * (Clearance Volume)
C.R. = E.R. = 8:1
In the LaForce engine (Figure 2) the clearance volume is smaller due
to the milling of the head and the swept volume remains the same (no
change in stroke or crankshaft was made), but the inlet valve closes
at a later time during the compression stroke than in the standard
engine. The volume between the point when the valve closes and TDC
can be referred to as Effective Swept Volume. Because of the delayed
valve closing the Effective Swept Volume is smaller, but since the
Clearance Volume is also smaller the compression ratio remains the
same.
C.R. - (Clearance Volume + Effective Swept Volume) * (Clearance Volume)
C.R. = 8:1
Due to the smaller Clearance Volume, expansion ratio is higher,
with the Ventur-E personnel claiming an expansion ratio 2 to 3 times
greater than in the standard engine. If one assumes the lower value
to be correct, the relationship between expansion ratio and volume is:
E.R. = (Clearance Volume + Swept Volume) T (Clearance Volume)
E.R. = 16:1
The available power is proportional to the volume of the fuel-
air charge remaining in the cylinder when the inlet valve closes,
for both the standard engine and the LaForce engine. To obtain the
increased expansion ratio the LaForce engine intakes only half as
much volume as the standard. Thus the effect of delayed valve closing
on power output can be approximately quantified as follows:
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Power, LaForce Engine
Power Ratio = 7: tr=7°
Power, Stock Engine
= Intake Charge, LaForce Engine
Intake Charge, Stock Engine
= (Clearance Volume + Effective Swept Volume) _ 8 _ 1
(Clearance Volume + Swent Volume) ~16 ~ 2
If, indeed, the LaForce engine has an expansion ratio 2 times that
of the standard engine, then its theoretical power output would be expected
to be one half that of the standard engine. The actual power output of
the LaForce engine was measured in the test program, as described on
page 20 of this report, and was about 20% lower than the standard engine.
This suggests that the expansion ratio is less than 2:1 in comparison
to a standard engine.
Figures 1 and 2, though dimensionally exaggerated, represent the
changes made to the shape of the combustion chamber merely by milling
the head. There is now a flat surface, which, with the piston at
TDC, creates a large "squish" area that is not present in the standard
engine. Squish areas cause quenching of the flame during combustion,
which results in increased hydrocarbon (HC) emissions. The LaForce
car thus might be expected to have higher HC emissions than the stock
cars.
The effect of the LaForce intake manifold is to separate larger
liquid fuel droplets from the stream of air, vaporized fuel and
entrained droplets flowing from the carburetor. This should result
in a more homogeneous mixture, good cylinder-to-cylinder distribution,
and the ability to run with a leaner air-fuel ratio. One drawback
of the LaForce manifold, as EPA's engineers understand it, is a
possible lack of air-fuel ratio control due to the sudden addition
of fuel vapor from the heaters during transient operation. This
richening, if it occurs, would result in higher carbon monoxide (CO)
emissions.
The concept of removing the larger fuel droplets from the fuel
air mixture delivered by the carburetor, and vaporizing them with
exhaust system heat, is not a new one. "Quick heat" or "Early Fuel
Evaporation (EFE)" manifolds have been developed by several auto
manufacturers, and some 1975 models already use such devices. The
EFE system consists of a modified intake manifold and exhaust system
plumbing arrangement which creates high temperatures at the floor of
the intake manifold to vaporize the fuel that is unable to remain
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entrained in the fuel-air mixture as it changes direction between the
carburetor and the intake ports. While most EFE - type systems utilize
exhaust heat to vaporize the fuel, a system under development by Chrysler
uses electric resistance to heat the intake manifold floor.
Other independent developers have also demonstrated mixture
improvement systems which EPA has evaluated in the past. Quoting from
EPA report number 72-20 (April 1972) on intake system modifications
made by Mr. Robert Edde, "The main feature of the system was a special
intake manifold which had been designed to remove liquid fuel from
the intake charge. This was accomplished by using a gap which could be
crossed only by fuel in the vapor state, suspended in the air charge
or clinging to the upper walls of the intake manifold." As with the
EFE concept and the LaForce concept the object is to vaporize liquid
fuel after it is brought into contact with a heat exchanger of some
type.
The intake systems developed by Edde, GM, Chrysler and others
have all demonstrated emissions as low as the 1975 Federal Standards
when installed on conventional engines without catalysts.
Test Program
A. Test Procedures
In order to respond fully to the Senate Public Works Committee
request of November 25, 1974, for an evaluation of the LaForce
vehicle, a broad range of emissions, fuel economy and performance
tests was carried out. These tests were conducted during the
program:
1. 1975 Federal Test Procedure (75 FTP)
This procedure, described more thoroughly in Appendix B (and in
complete detail in Reference 1), is the procedure used in the
certification tests of new cars beginning with the 1975 model
year. It is also the procedure EPA has been using since 1971 to
evaluate prototype engines and emission control systems. The
1975 FTP provides the most representative characterization
available of exhaust emissions and urban fuel economy. During
the test the vehicle is driven on a chassis dynamometer over a
stop-and-go driving schedule having an average speed of about
20 mph. Through the use of flywheels and a water brake, the
loads that the vehicle would actually see on the road are
simulated. The vehicle's exhaust is collected, diluted and
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thoroughly mixed with filtered make-up air, to a known constant
volume flow, using a positive displacement air pump. (This
procedure is known as Constant Volume Sampling - CVS).
A continuous sample of the diluted exhaust-air stream is collected
and pumped into impermeable, chemically inert Tedlar sample bags
(evacuated at the start of the test) during the test period. At
the end of the test period the samples are analyzed for
concentrations of HC, CO, NOx and CO- (carbon dioxide). The
sample probe is a quarter-inch diameter stainless steel tube,
placed diametrically across the duct, having a number of equally
spaced holes which face upstream. Previous studies involving
cars powered by various gasoline - fueled conventional engines,
stratified charge engines and rotary engines, and using heated
and non-heated FID instrumentation, have confirmed that 1) the
exhaust-air stream at the sample point is homogeneous and 2)
the sample collected is representative.
2. EPA Highway Cycle (HWC)
This test, which employs the same dynamometer and sampling
procedure as the 1975 FTP, provides exhaust emissions and
fuel economy information for non-urban conditions. The driving
schedule has a length of about 10.2 miles and an average speed
of 48.6 mph. The highway driving schedule is described in
detail in Reference 2.
3. Steady State Tests
These tests, again employing the chassis dynamometer and CVS system,
are routinely conducted at MVEL on prototype systems to help give
insight into the operational differences and exhaust emission and
fuel economy variations among vehicles. Speeds between 0 and 60
mph are investigated. Steady state data must be interpreted
cautiously, because the vehicle is being exercised in an
unrepresentative manner. Many vehicle operation surveys conducted
by EPA and others have clearly shown that true steady state
operation rarely occurs in customer use.
4. Acceleration Tests on Chassis Dynamometer
Wide open throttle (WOT) acceleration from 0 to 60 mph were
conducted on the chassis dynamometer to help assess the relative
performance and power output of all test cars except the 1975
standard Hornet. Neither emissions nor fuel economy were
measured during these tests, only the 0 to 60 mph time in seconds.
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5. Acceleration Tests on Test Track
At the request of EPA, General Motors Corporation consented to
run acceleration tests, on the two cars supplied by Ventur-E, at
the GM Proving Ground near Milford, Michigan. The tests, conducted
by personnel from GM's Product Evaluation group, consisted of
1) a standing start, WOT acceleration to one quarter mile, 2) a
30 to 70 mph WOT acceleration simulating the acceleration of a
car on an expressway entrance ramp, and 3) the U.S. Department
of Transportation (National Highway Traffic Safety Administration)
low speed and 4) high speed passing maneuvers. The former is
a 20 to 35 mph WOT acceleration, the latter a 50 to 80 mph WOT
acceleration.
In tests 1) and 2) the cars were run at a weight of 3500 pounds,
which included the driver, test gear and an observer. In 3) and
4) the cars were tested at the gross vehicle weight of 4176 pounds,
which included the driver, test gear, two observers and bags of
lead shot.
For reasons of insurance coverage, test track safety, and experience
with the test track layout and test procedures, if was understood
beforehand that the drivers in all tests would be GM personnel.
A fifth wheel, attached to the rear bumper of each car, furnished
signals to the on-board data acquisition system which computed
and printed out speed, time and distance.
6. Maximum Power Tests on Electric Chassis Dynamometer
The LaForce-modified Hornet and the EPA-rented 1974 Hornet were
subjected to tests on a large roll (48" diameter) electric
chassis dynamometer. At three different vehicle speeds - 50,
55 and 60 mph - the maximum power output at the rear wheels
was determined.
B. Test Fuels
Leaded Indolene 30 gasoline, one of the standard test fuels used
by EPA, was used in the first two series of emissions tests (1975
FTP, Highway Cycle, Steady States) on the LaForce car, the LaForce -
supplied 1974 Hornet, and the EPA-rented 1974 Hornet. At the request
of Ventur-E representatives a leaded pump gasoline (Mobil Regular)
was used in subsequent tests in all three cars.
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il
The reason given by Ventur-E personnel for this request was that
their entire engine/intake system was developed using normal pump
gasoline. Their claim was that Indolene is sufficiently different
from pump gasoline in its mixture of hydrocarbon components that
the full effect of the LaForce intake system may not be realized
if Indolene is used, resulting in higher emissions and degraded
performance.
By EPA specification (Reference 1) Indolene is a relatively
non-volatile, summer-grade fuel with a Reid Vapor Pressure (RVP) of
about 9 pounds. In contrast the Mobil Regular purchased at a
local service station was a winter-grade, relatively volatile
fuel of 11.3 pounds RVP. A copy of the EPA distillation report is
included in Appendix F. The rented 1975 Hornet was run on non-
leaded Indolene in both series of tests run on it.
C. Fuel Economy Calculations
EPA normally computes fuel economy from chassis dynamometer
CVS tests using the carbon - balance method. Explained in
References 3 and 4, it makes use of HC, CO and C02 mass emissions
data and the assumptions that 1) all carbon in the exhaust is in
the form of either HC, CO or C02, and 2) all carbon in the exhaust
came from the fuel. This method is accurate, repeatable, and
simple since those three emissions are always measured. However,
in response to requests made by Ventur-E representatives, fuel
economy was also determined by a gravimetric method, in which
the weight of the fuel used during a test was measured. Because
of the relatively crude apparatus employed by EPA for this method,
it is less accurate, with greater test-to-test variability. The
combination of vapor locks in the plumbing, the loss of fuel vapors
escaping from the weigh can and evaporative losses in the vehicle's
fuel system during a test causes fuel economy determined by the
gravimetric method to be less reliable than that determined
by the carbon balance method.
Gravimetric fuel economy was measured in all chassis dynamometer
tests on the LaForce car and the LaForce - supplied 1974 Hornet,
and on most chassis dynamometer tests run on the EPA - rented 1974
Hornet.
D. Tuning and Adjustment of Test Cars
Consistent with procedures followed in other EPA device evaluation
test programs, Ventur-E personnel were invited to tune both their cars
to their desired timing, idle speed and idle CO settings at the
beginning of the test program.
EPA engine diagnostic equipment and laboratory personnel were
made available for this initial tuneup.
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12
No adjustments were allowed to be made on the LaForce modified
car after the initial settings by LaForce. This practice is consistent
with EPA policy in the conduct of tests of this type, the purpose of
which is to evaluate as fully as possible the validity of claims being
made for a particular development. Because there can be test-to-test
variability, EPA's general practice is to run a series of at least
three complete tests, and to use the average of the results of the
several tests as the best estimate of the performance of the vehicle
under test. Obviously, it is necessary to avoid changing the calibra-
tions of the test vehicle while these repeat tests are being made, for
to make such changes would invalidate the objective of avoiding skewed
results which can be caused by random test variability. In fact,
calibration parameters on the LaForce car were checked prior to each
test to assure that no malfunction or calibration shift had occurred.
Changes were made to timing and carburetor parameters on the
EPA-rented 1974 Hornet, however, after the first two series of tests
(1975 FTP, Highway Cycle, Steady States). The reason for this was
to allow a comparison of the LaForce car with the stock car and also
with the stock car adjusted for better economy. Starting with the same
car, two different approaches to improve fuel economy were taken: the
LaForce modifications and the EPA adjustments, and a comparison of the
results allows an assessment of the LaForce engine in the proper context:
the fuel economy improvements possible with two different modifications
to the same basic engine.
The rented Hornet was selected as the best vehicle for comparison
purposes for these reasons:
1. It was not supplied by Ventur-E, Inc. and therefore EPA
was relatively free to make adjustments.
2. Nearly all of the recommended break-in mileage had been
accumulated on it, while the Ventur-E supplied standard car had
less than half that mileage.
The Ventur-E supplied standard Hornet and the rented 1975 Hornet
were not subjected to as many comparison tests because they were not
considered fully comparable, inasmuch as they were not fully broken-
in. Had they been fully broken-in their fuel economy would probably
have been one to two miles higher.
The rented standard 1974 Hornet was tested in two different
configurations: 1) adjusted to manufacturer's specifications and
2) recalibrated for better fuel economy, to better determine the
fuel economy potential of the standard engine.
E. Proposal to Isolate Effects of LaForce Modifications
Part way into the test program it was proposed to Ventur-E
representatives by EPA that a study be undertaken to determine how
much each of two basic LaForce modifications, the intake system
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13
and the valve timing change, contributed to the total. This would be
accomplished by removing the intake and exhaust systems from the modified
car and installing them on the standard 74 Hornet furnished by Ventur-E.
Also, the standard intake and exhaust systems would be mounted on the
modified engine. It was felt that this cross-switch of components
would allow EPA personnel to determine the effect of the intake system
alone and of the valve timing changes alone. It was proposed that
the cross-switch would be performed by EPA laboratory personnel, in
the MVEL, under the direction of Ventur-E personnel
While Ventur-E personnel were willing to permit the cross-switch
experiment, EPA personnel accepted the persuasive arguments that
Ventur-E had been making against the experiment: that the cross-
switch would take at least two days to accomplish, that several more
days might be spent in trying to make both engines run optimally,
and finally that the amount of useful information likely to be
derived did not justify the effort required. Hence, the cross-switch
tests were not conducted by EPA.
Results and Discussion
As shown in the first three columns of Table 1, exhaust emission
levels of the LaForce - modified car were generally higher than the
emissions of the stock vehicles. Specifically, HC emissions from
the LaForce car were 72% higher than those from the economy-tuned
1974 Hornet, and CO emissions were 265% higher. The higher HC and CO
emissions indicate that the LaForce engine had less complete combustion
of the fuel than the standard vehicles. The lower exhaust temperatures
measured at the tailpipe (see Table 2) could be an indication of lower
exhaust temperatures at the engine. This would contribute to the
higher HC and CO emissions of the LaForce car by reducing post-
cylinder oxidation reactions.
All fuel economy data reported herein were calculated by the
carbon-balance method.* The fuel economy of the LaForce car was
significantly higher than the Ventur-E furnished and EPA -rented
standard versions of the Hornet. However, recalibration of the
EPA - rented standard Hornet narrowed the composite fuel economy
difference to 8%. (Composite fuel economy is explained in Appendix G)
The comparison in Table 1 of data from the rented 1974 Hornet (3) and
data on the 1975 Hornet (4) acquired during the 1975 certification
program, indicates the trend in emissions and fuel economy resulting
from AMC's current optimization programs. The 1975 Hornet is
simultaneously demonstrating 8% better composite fuel economy than
the 1974 Hornet and substantially lower emissions. The NOx emissions
* See Appendix H for comparison of gravimetric fuel economy and
carbon-balance fuel economy.
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-------
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13b
TABLE 2
TEMPERATURE COMPARISON
Temperatures taken on LaForce car and LaForce-supplied standard
car at tailpipe. Temperatures mentioned here are highest for the
particular test phase or cycle. A reading of 500+ denotes that
the temperature went off scale.
Cycle
Bag 1 of 1975 FTP
Bag 2 of 1975 FTP
Bag 3 of 1975 FTP
Hiway
Idle
15 Steady State
30 Steady State
40 Steady State
50 Steady State
60 Steady State
Temperature, F
LaForce
(avg. of 2 pipes)
160
155
165
320
140 (still hot from
Hiway cycle)
125
142
195 upward trend
265 upward trend
350 upward trend
Standard Car
450
455
439
500+ for entire test
215 constant
228 constant
380 steep upward trend
437 constant
500+
500+
-------
-------
13c
Table 3
Maximum Power @ Rear Wheels, Electric Dynamometer
1) HP
T x N
5250
where
N = rpm of dyno roll
T = torque at dyno roll, ft - Ibs
dyno roll diam. = 48"
Vehicle
Speed,
mph
Engine
Speed,
rpm
Torque at
Rear Wheels,
ft - Ibs
Calculated
Horsepower
at Rear Wheels
LaForce Car
EPA-rented
74 Hornet
Economy-Tuned
50
55
60
50
55
60
3500
3850
3850
EPA-rented
74 Hornet
Mfrs. Spec
50
55
60
3050
3300
3500
3025
3300
3435
830
815
600
1032
968
893
1038
955
887
55.4
59.8
48.0
68.8
71.0
71.5
69.2
70.1
71.0
-------
-------
13d
W
C/2
Pi
O
SB
w
W
Pi
70
60
50
40
Stock '74 Hornet
manufacturers specifications
economy tuned
32% loss
LaForce Car
50 55 60
VEHICLE SPEED (MPH)
Figure 3. REAR WHEEL HORSEPOWER
LAFORCE VS. STANDARD VEHICLE
-------
-------
14
from the 1974 Hornet, as recalibrated by EPA for fuel economy (2) were
higher than before recalibration, but the use of proportional EGR would
be expected to reduce NOx without adversely affecting economy. With
the use of improved emission control techniques such as catalytic
converters and proportional EGR systems, future versions of the AMC
Hornet would be capable of duplicating the fuel economy of the LaForce
car with an even greater advantage in emission control than is evident
from these tests.
On an equal performance basis (Reference 2) the fuel economy
of the 1974 Hornet as recalibrated by EPA was essentially equivalent
to the LaForce vehicle. As explained in the "Vehicle Description"
section of the report the intake valve timing modifications made by
LaForce would be expected to reduce the maximum power output of the
engine. The 0 to 60 mph acceleration times shown in the last two
columns of Table 1 indicate a 20% power loss for the LaForce engine
compared to the economy-tuned 1974 Hornet (2), and about a 17% power
loss compared to the stock 1974 Hornet at manufacturer's specifications
(3). Appendix C shows the computation of this power difference.
A nominal 20% power loss is also apparent from the full load steady
state tests run on the electric chassis dynamometer. The results
of these tests are tabulated in Table 3 and shown in Figure 3.
Appendix D explains the calculations necessary to correct the economy
of the standard Hornet to the performance level of the LaForce car.
Note that the difference in axle ratio was also considered in the
calculations. As shown in the seventh column of Table 1, on an
equal performance basis the difference in composite fuel economy
between the LaForce car and the economy-tuned 1974 Hornet is less
than 2%.
Differences in economy between the two standard 1974 Hornets (3)
and (6) and between the two 1975 Hornets (4) and (5) are at least
partially attributable to the differences in mileage accumulated
on each vehicle. In both cases the car with poorer fuel economy had
accumulated fewer miles. The AMC six-cylinder engine is known to require
a substantial break-in period (approximately 5000 miles) during which
time the fuel economy can be expected to improve by 1-2 mpg.
Differences in fuel economy between the "economy tuned" Hornet (2) and
the stock configuration of the car (3) were due primarily to increased
vacuum spark advance and increased initial spark advance. The 1974
Hornet relies on spark retard for NOx control possibly because of the
low production cost associated with that control approach; it could
deliver better fuel economy with acceptable emissions if a better EGR
system were used.
-------
-------
14a
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14b
50 .-
LaForce Car
25
3 40
!
w
CO
w
a 30
o
8
w
w
E
74 Hornet,
Economy Tuned
20
10
74 Hornet,
Manufacturer's
Specifications
75 Hornet
Manufacturer' s
Specifications
(not broken in)
10
20 30 40 5(
STEADY STATE SPEED, MILES PER HOUR
Figure 4. FUEL ECONOMY VERSUS SPEED
-------
-------
15
The modulation of spark timing used by AMC results in the greatest
fuel economy loss during low speed cruises. The earlier tests reported
by LaForce, such as the test at the Dover Downs race track, compared
fuel economy during low speed cruises, and the fuel economy advantage
of the LaForce car over the standard Hornet was at its greatest at these
low speeds. This driving mode (30 mph cruise) coupled with the fact
that the comparison car used by LaForce was not fully broken-in, in
the judgement of EPA, causes the difference in fuel economy claimed by
Ventur-E to be somewhat exaggerated.
The steady state economy data measured by EPA are summarized in
Table 4 and plotted in Figure 4. The most significant difference
between the LaForce car and the EPA economy-tuned Hornet occurred at
idle. This difference could be due in part to the effects of the valve
timing modifications made by LaForce.
Detailed emissions, fuel economy and performance data for all tests
can be found in Appendix E. Tables E-l and E-2 indicate that a slight
decrease in HC and CO emissions from the LaForce car, accompanied by
a slight increase in NOx emissions, occurred when the more volatile
pump gasoline was used, as would be expected. The differences in fuel
economy are considered insignificant. The same effects are seen in
the steady state data.
Performance test data are shown in Table E-10. The LaForce car
is seen to be slower in all acceleration modes. At the time this
report was prepared, the final report on acceleration tests at the
GM Proving Ground had not been received. Preliminary data available
at the end of testing are presented in Table E-ll.
All vehicles involved in the program were free of any driveability
problems.
The claims made for the LaForce engine, listed earlier in this
report, may now be compared with the results of the EPA evaluation
program.
1) In maximum - power tests made at three different vehicle
speeds on an electric chassis dynamometer, the LaForce car delivered
15 to 32% less power than the economy-tuned standard car.
2) Road tests and dynamometer tests showed that the LaForce car
had lower acceleration than the standard car. The LaForce car required
about 10% more time to reach 60 mph from a standing start.
-------
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-------
-------
17
References
1. Environmental Protection Agency, "New Motor Vehicles and New Motor
Vehicle Engines". Federal Register, Volume 37, No. 221, Part II,
November 15, 1972, pages 24, 250 - 24, 320.
2. Thomas C. Austin, Karl H. Hellman, and C. Don Paulsell, "Passenger
Car Fuel Economy During Non-Urban Driving", Paper No. 740592, Society
of Automotive Engineers.
3. Thomas C. Austin and Karl H. Hellman, "Passenger Car Fuel Economy -
Trends and Influencing Factors", Paper No. 730790, Society of Auto-
motive Engineers.
4. Environmental Protection Agency, "Control of Air Pollution from
New Motor Vehicles and Engines - Federal Certification Test Results
for 1974 Model Year". Federal Register, Volume 38, No. 212, Part II,
November 5, 1973, page 30494.
-------
-------
18
Appendix A
Vehicle Descriptions
The cars described in the following tables were similar in these
respects: weight, transmission type, basic engine, and chassis.
The LaForce - modified car differed from the other three in
axle ratio, 3.08:1 compared to 2.73:1 for the other three cars.
Had the LaForce car also been equipped with a 2.73 rear axle, it is
expected that its fuel economy would be slightly better and its
acceleration times slightly worse. The effect on emissions is
impossible to estimate.
The LaForce - supplied standard 74 Hornet and the EPA - rented
75 Hornet were both considered to be not broken-in because of low
mileage accumulation at the start of the test program.
Manufacturer's specifications for initial timing and idle
CO concentration are as follows:
'74 Hornet: 3° + 2 1/2° BTDC @ 700 rpm/Dr
1 - 1.5% CO
3° + ;
1% CO
'75 Hornet: 3° + 2° BTDC @ 550 rpm/Dr
-------
-------
19
TABLE A-l
TEST VEHICLE DESCRIPTION
Chassis model year/make - 1974 AMC Hornet, LaForce modified vehicle
Source: Ventur-E, Inc.
Engine
6,
type to
bore x stroke 3.75 x 3.90 in. (95.2 x 99.1 mm)
displacement 258 CID (4229 cc)
compression ratio 8.0:1
max. power @ rpra 89 hp (66.4 kW) @ 3500 rpm (estimated)
fuel metering IV fixed orifice carburetor
fuel requirement 91 RON leaded
exhaust system dual
Drive Train
transmission type 3 speed automatic
final drive ratio 3.08:1
Chassis
type Unitized, front engine, rear wheel drive
tire size C78 x 14
curb weight 3050 Ibs (1383 kg)
inertia weight 3500 Ibs (1588 kg)
passenger capacity 5
Emission Control System
engine modifications
Initial Test Conditions
Odometer reading 8295 miles
Ignition timing 7 BTDC
Idle CO concentration 0.15%
-------
-------
20
TABLE A-2
TEST VEHICLE DESCRIPTION
Chassis model year/make - 1974 AMC Hornet
Source: Ventur-E, Inc.
Engine
4 cycle.nOHV, In-Line 6, Wedge head,
type Otto cycle
bore x stroke 3.75 x 3.90 in. (95.2 x 99.1 mm)
displacement 258 CID (4229 cc)
compression ratio 8.0:1
max. power @ rpm 110 hp (82 kW) @ 3500 rpm
fuel metering IV fixed orifice carburetor
fuel requirement 91 RON leaded
exhaust system single
Drive Train
transmission type 3 speed automatic
final drive ratio 2.73:1
Chassis
type Unitized, front engine, rear wheel drive
tire size 6.95 x 14
curb weight 2950 Ibs (1338 kg)
inertia weight 3500 Ibs (1588 kg)
passenger capacity 5
Emission Control System
engine modifications
Initial Test Conditions
Odometer reading 1995 miles
Ignition timing 5
Idle CO concentration 0.1%
-------
-------
21
TABLE A-3
TEST VEHICLE DESCRIPTION
Chassis model year/make - 1974 AMC Hornet
Source: EPA - supplied, rented from local dealer
Engine
4 cycle.,OHV, In-Line 6, Wedge head,
type Otto cycle '
bore x stroke 3.75 x 3.90 in. (95.2 x 99.1 mm)
displacement 258 CID (4229 cc)
compression ratio 8.0:1
max. power (? rpm 110 hp (82 kW) @ 3500 rpm
fuel metering IV fixed orifice carburetor
fuel requirement 91 RON leaded
exhaust system single
Drive Train
transmission type 3 speed automatic
final drive ratio 2.73:1
Chassis
type Unitized, front engine, rear wheel drive
tire size ! . ! . 6-95 x 14
curb weight 2950 Ibs. (1338 kg)
inertia weight 3500 Ibs. (1588 kg)
passenger capacity 5
Emission Control System
engine modifications
Initial Test Conditions
Odometer reading 4?30 miles
Ignition timing . ". 5 BTDC
Idle CO concentration 1.0%
-------
------- An error occurred while trying to OCR this image.
-------
-------
23
Appendix B
1975 Federal Exhaust Emission
Test Procedure
The Federal procedure for emission testing of light duty vehicles
involves operating the vehicle on a chassis dynamometer to simulate
an 11.1 mile commuting trip in an urban area. Through the use of
flywheels and a water brake, the vehicle's actual load on a level
road is simulated. The driving schedule is primarily made up of stop
and go driving and includes some operation at speeds up to 57 mph.
The average vehicle speed is approximately 20 mph. The 1975 FTP
captures the emissions generated during a "cold start" (12-hour soak
-------
-------
24
Appendix C
The product of power times time required to reach 60 mph is the
same for two vehicles accelerated from a stop, since their kinetic
energy is equal at a given speed. This can be expressed as:
Vl = V2 (1)
where: PI is the rated power of the standard Hornet engine (110 hp)
t is the time it takes the standard Hornet to accelerate
P. is the power of the LaForce engine
t_ is the time it would take the LaForce vehicle to reach
60 mph with the same axle ratio as used in the standard
Hornet .
Correcting the 0-60 time for the LaForce vehicle for the 10% difference
in axle ratio would be expected to increase the 0-60 accel time by
about 3% according to Huebner .
1.03 x 17.6 = 18.3 = t2 (2)
substituting the known values from equation (2) and Table 1 into
equation (1) :
(HOhp) 14.8 sec = P (18.3 sec)
89hP = P2
The percentage power loss for the LaForce engine is
~ P2)/P1 = (11° ~ 89)/110 = 20%
G.J. Huebner Jr. and D.J. Gasser, "General Factors Affecting
Vehicle Fuel Consumption", SAE paper 730517, 1973.
-------
-------
25
Appendix D
Constant Performance Correction Factor Calculation From
SAE paper 730790:
MPG = A + B (1_) + C (HP) + D (HP ) + E (AR) + F (HP) + G (CID) (1)
IW IW CID
where: A = 5.6678
B = 48,702
C = -204.32
D = 3.2784
E = -.66387
F = .03012
G = -.00909
IW = inertia weight
HP = rated horsepower
CID = engine displacement
AR = axle ratio
substituting the values for the standard '74 Hornet
MPG = 13.71 (2)
Substituting the values for a modified Hornet with a 3.08 axle and an
89 hp, 209 CID engine ( same specific power):
MPG = 14.58 (3)
The ratio of (3) over (2) is the correction factor to be applied to
the actual test results of the standard Hornet:
.. '71 = 1.064 = correction factor
-------
-------
26
Appendix E
Emission, Fuel Economy, and Performance Results
The following pages present the detailed data generated on the
test cars in the EPA test program. The results are listed for each
individual test, and averages are calculated when multiple tests
were run.
On Tables E-l to E--9 the third test listed for the LaForce
supplied 1974 standard Hornet and for the LaForce modified car was
run, in each case, using Mobil Regular leaded gasoline obtained from
a local retail station (see page 10 of test report). On the rented
1974 Hornet the tests in which the cars were adjusted to the LaForce
standard car specifications and as well as the tests that were run
with the car in 'fuel economy tuned' condition were run on the same
Mobil Regular gasoline. All other tests were run on Indolene leaded
test gasoline, except that the 1975 car was run on the Indolene unleaded
gasoline, for that car was certified using unleaded gasoline. All
performance tests were run on Mobil Regular leaded gasoline.
-------
-------
27
Table E-l
1975 FTP
Mass Emissions City Fuel
Grams Per Mile Economy
HC CO NOx mpg
LaForce-Supplied 74 Hornet .67 5.39 3.49 14.5
.68 5.42 3.52 14.7
.70 5.07 15.4
avg. .68 5.29 3.50 14.8
LaForce Modified Car
avg. 2.87 22.57 3.30 -~.~
Rented 74 Hornet -
(Mfrs. Specs.) 1.16 19.5 2.72 15.3
1.18 20.4 2.92 15.4
3.05
2.89
2.69
25.6
21.8
20.3
3.22
3.29
3.40
20.3
20.8
20.8
avg.
1717 19-9 2.82 15.3
Rented 74 Hornet - _ -
(.2% CO, 10° BTDC)* 1-22 6.43 4.14 17.1
Rented 74 Hornet -
(Economy Tuned)
Rented 75 Hornet
avg.
avg.
1.68
1.66
1.67
1.83
1.55
1.67
5.85
6.53
6.19
18.8
14.9
16.8
4.89
4.76
4.82
2.94
3.25
3.10
18.6
18.9
18.8
15.6
16.8
16.2
* Adjusted approximately to specifications of the LaForce Modified Car.
-------
-------
28
Table E-2
Federal Highway Cycle
Mass Emissions
Grams Per Mile
LaForce-Supplied 74 Hornet
avg.
LaForce Modified Car
avg.
Rented 74 Hornet
(Mfrs. Specs.)
Rented 74 Hornet
(.2% CO, 10° BTDC) *
Rented 74 Hornet -
(Economy Tuned)
Rented 75 Hornet
avg.
avg.
avg.
HC
.43
.47
.48
.46
2.29
2.30
1.96
2.18
.52
.58
.55
.73
.76
.71
.74
.67
.80
.74
CO
2.22
2.28
2.45
2.32
6.50
6.99
5.39
6.29
3.68
3.90
3.79
2.51
2.57
2.58
2.58
5.63
9.76
7.69
Highway Fuel
Economy
NOx mpg
4.61 23.1
5.35 22.6
5.34 23.9
5.10 23.2
4.58 27.3
4.74 26.9
5.20 27.8
4.84 , 27.3
3.66 24.3
4.34 23.4
4.00 23.8
6.99 24.7
5.35 25.4
5.73 25.9
5.55 25.6
2.51 21.2
2.58 22.1
2.54 21.6
* Adjusted approximately to specifications of the LaForce Modified Car.
-------
-------
29
Table E-3
Steady State - Idle
Mass Emissions
Grams Per Minute Fuel Consumption
HC CO NOx gph
LaForce-Supplied 74 Hornet .186 .328 .064 .574
.176 .332 .052 .558
.138 .340 .056 .540
avg. .166 .334 .058 .558
LaForce Modified Car .296 .604 .044 .339
2.154 .056 .360
.278 .064 .365
avg. .302 1.012 .054 .355
Rented 74 Hornet -
(Mfrs. Specs.) .376 9.12 .050 .594
.394 8.64 .058 .609
avg. .384 8.88 .054 .603
Rented 74 Hornet - .316 2.488 .082 .558
(.2% CO, 10 BTDC)*
Rented 74 Hornet - .390 1.122 .148 .556
(Economy Tuned) .404 2.036 .148 .563
avg. .396 1.580 .148 .561
Rented 75 Hornet .232 .974 .198 .561
.298 3.820 .206 .585
avg. .264 2.396 .202 .574
* Adjusted approximately to specifications of the LaForce Modified Car.
-------
-------
30
Table E-4
Steady State - 15 mph
HC
Mass Emissions
Grams Per Mile
CO
NOx
Fuel
Economy
LaForce-Supplied 74 Hornet
avg.
LaForce Modified Car
Rented 74 Hornet
(Mfrs. Specs.)
Rented 74 Hornet
(.2% CO, 10° BTDC)*
Rented 74 Hornet
(Economy Tuned)
Rented 75 Hornet
avg.
avg.
avg.
avg.
.41
.44
.50
.45
1.10
1.12
1.06
1.09
1.41
1.41
1.41
1.96
1.85
2.59
2.13
2.08
2.07
2.02
2.06
23.12
20.64
21.88
.68
.53
.54
.58
.51
.50
.38
.46
.34
.31
.32
19.2
21.5
22.5
21.0
27.3
27.8
25.9
27.0
23.4
23.3
23.3
1.34
1.53
1.46
1.50
1.00
1.00
1.00
14.28
2.82
3.62
3.22
2.52
4.07
3.30
.32
.48
.50
.49
1.54
1.14
1.34
24.9
26.7
26.7
26.7
21.8
25.0
23.3
Adjusted approximately to specifications of the LaForce Modified Car.
-------
-------
31
Table E-5
Steady State - 30 mph
HC
Mass Emissions
Grams Per Mile
CO
NOx
Fuel
Economy
mpg
LaForce-Supplied 74 Hornet
avg.
.11
.12
.09
1.45
1.44
1.31
1.13
.96
.89
21.7
23.0
24.1
.11
1.40
.99
22.9
LaForce Modified Car
avg.
1.13
1.09
.86
1.72
1.64
1.62
1.33
1.33
1.44
37.6
37.3
36.7
1.03
1.66
1.37
37.2
Rented 74 Hornet
(Mfrs. Specs.)
avg.
.13
.16
.14
1.35
1.40
1.38
.73
.71
24.6
24.7
24.6
Rented 74 Hornet
(.2% CO, 10° BTDC)*
,28
1.51
.78
21.5
Rented 74 Hornet
(Economy Tuned)
Rented 75 Hornet
avg.
avg.
.79
,72
,76
.73
.66
.70
1.43
1.41
1.42
2.16
1.90
2.03
1.33
1.22
1.28
2.91
2.31
2.61
31.5
32.8
32.1
26.2
30.2
28.1
Adjusted approximately to specifications of the LaForce Modified Car.
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32
Table E-6
Steady State - 40 mph
HC
Mass Emissions
Grams Per Mile
CO
NOx
Fuel
Economy
LaForce-Supplied 74 Hornet
avg.
LaForce Modified Car
avg.
.40
.46
.38
1.75
1.76
1.78
2.12
2.09
1.95
27.1
28.0
29.4
.41
1.46
1.76
1.82
2.05
2.83
28.1
1.55
1.55
1.29
2.08
1.81
1.57
2.73
2.82
2.93
35.0
34.7
34.4
34.7
Rented 74 Hornet
(Mfrs. Specs.)
avg.
.53
.56
.54
1.72
1.70
1.71
1.70
1.71
1.70
28.8
29.0
28.9
Rented 74 Hornet
(.2% CO, 10 BTDC)*
.64
1.74
2.47
29.9
Rented 74 Hornet
(Economy Tuned)
Rented 75 Hornet
avg.
avg.
.68
.65
.66
.92
.86
.87
1.70
1.70
1.70
7.59
7.39
7.49
2.48
2.33
2.40
3.37
3.09
3.23
30.6
30.7
30.6
25.7
28.1
26.8
Adjusted approximately to specifications of the LaForce Modified Car.
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33
LaForce-Supplied 74 Hornet
LaForce Modified Car
Rented 74 Hornet
(Mfrs. Specs.)
Rented 74 Hornet
(.2% CO, 10° BTDC)*
Rented 74 Hornet
(Economy Tuned)
Rented 75 Hornet
Table
Steady State
HC
^
.
avg.
1.
I.
1.
avg. 1.
%
avg.
.
avg.
.
avg.
E-7
-
38
45
46
43
84
87
59
77
48
55
52
67
63
59
61
83
92
88
50 mph
Mass Emissions
Grams Per Mile
CO
2.01
2.04
1.98
2.01
4.09
4.25
2.73
3.69
2.11
2.06
2.08
1.99
1.99
1.94
1.96
5.28
8.40
6.84
NOx
4.01
4.35
4.33
4.23
4.
4.
25
31
4.51
4.36
3.32
3.47
3.40
5.53
5.22
4.70
4.46
1.65
1.28
1.46
Fuel
Economy
mp_g_
24.8
25.4
25.9
25.4
29.6
29.5
30.5
29.8
26.2
26.4
26.3
26.4
27.4
28.6
28.0
* Adjusted approximately to specifications of the LaForce Modified Car.
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34
Table E-8
Steady State - 60 mph
LaForce-Supplied 74 Hornet
avg.
LaForce Modified Car
avg.
Rented 74 Hornet
(Mfrs. Specs.)
avg.
Rented 74 Hornet
(.2% CO, 10° BTDC)*
Rented 74 Hornet
(Economy Tuned)
avg.
avg.
Mass Emissions
Grams Per Mile
HC
?.
2
1
2
.29
.29
.32
.30
.20
.17
.81
.06
.37
.43
.40
.54
.56
.52
.54
.47
.63
CO
2.
2.
2.
2.
6.
7.
5.
6.
2.
2.
2,
2
2
2
2
4
6
NOx
41
39
09
30
76
48
14
46
,59
.55
.57
.43
.41
.41
.41
.27
.60
6.
6.
6.
6.
5.
5.
6.
5.
5.
5,
5,
8
8
7
7
3
3
00
27
96
41
66
92
13
90
.07
.45
.26
.38
.01
.44
.72
.40
.32
Fuel
Economy
mpg
21.
21.
22.
21.
24.
24.
25.
24.
22.
22.
4
7
4
8
6
6
0
7
,8
,7
22.7
22,
23
24
23
19
20.
.9
.2
.1
.6
.4
J.
755 5.43 3.36 20.0
* Adjusted approximately to specifications of the LaForce Modified Car.
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35
Table E-9
Steady State - 30 mph No L. ad
Mass Emissions Fuel
Grams Per Mile Economy
HC CO NOx mpg
LaForce-Supplied 74 Hornet
avg.
LaForce Modified Car
avg.
Rented 74 Hornet
(Mfrs. Specs.) .15 1.30 .55 28.0
.14 1.28 .52 28.2
.09
.09
.20
.13
1.16
.97
.78
.97
1.24
1.23
3.59
2.02
2.25
1.97
1.67
1.96
.70
.68
.60
.66
.87
.84
.78
.83
25.6
26.0
27.0
26.2
41.6
42.2
40.5
41.4
avg.
.14 1.29 .54 28.1
Rented 74 Hornet
(.2% CO, 10° BTDC) * .68 7.58 .49 31.4
Rented 74 Hornet
(Economy Tuned) .76 1.74 .70 36.6
.63 1.23 .66 37.5
avg. .70 1.48 .68 37.0
Rented 75 Hornet .43 1.32 1.53 30.4
.66 3.97 1.64 33.3
avg. .54 2.64 1.58 31.8
* Adjusted approximately to specifications of the LaForce Modified Car.
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36
Table E-10
Chassis Dynamometer Acceleration Tests
Time, Seconds to Speed, mph
0-30 0-40 0-50 0-60
LaForce-Supplied
74 Hornet
5.0
8.1
11.8
16.4
LaForce Modified Car 5.4
9.1
13.0
17.6
Rented 74 Hornet
(Mfrs. Specs.)
15.2
Rented 74 Hornet
(Economy Tuned)
7.6
10.9
14.8
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37
0-30 raph
0-60 mph
0-1/8 mile
0-1/4 mile
30 to 70 mph
Table E-ll
GM Proving Ground Acceleration Tests
Time in Seconds, to Speed, mph, and Distance
LaForce-Supplied
74 Hornet
LaForce
Modified Car
5.7
18.1
14.1
21.7
21.5
7.0
19.9
15.3
23.0
22.5
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38
Appendix F
PETROLEUM DISTILLATION
SAfoPLt iDENT IFiCAT I ON
TEST NUMBER
DATE TAKEN fX~/
DATE ANALYZED
BAROMETRIC PRESSURE
DEGREES F
!BP _
10 ML
20 ML
30 ML /*?_ __ " V
40 ML
50 ML _£'.0
60 ML %
, W/O I w i |» t
90% POINT
FP -
36
"7
DEGREES F
70 ML _JL2JhT
80 ML ?/ ^-
90 ML 3 *f
END POIKT ^
DRY POINT
FINAL VOLUME
P.f-ID VAPOR PRESSURE /I ~ °$
"IBP 1f*- °F
*F
POUNDS
« r
1
Of
°F
ML
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39
Appendix G
Composite Fuel Economy Calculation
City cycle and Highway cycle fuel economy values can be "mileage
weighted" together to produce a "composite" fuel economy value that
reflects the relative amounts of automobile travel in urban and non-
urban areas. The fractions of automobile distances (mileage)
travelled in urban and non-urban areas are known to be .55 and .45,
respectively. Thus the formula used to "mileage - weight" city and
highway fuel economy values is:
mpg composite =
.55 + .45
mpg city mpg highway
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40
Appendix H
Comparison of Carbon Balance and Gravimetric Fuel Economy
In this table the Carbon Balance Fuel Economy is taken as the
standard. Gravimetric Fuel Economy is compared to Carbon Balance in
terms of percent difference. A negative percentage means Gravimetric
Fuel Economy is lower (poorer) than Carbon Balance; a positive
percentage means Gravimetric Fuel Economy is higher (better) than
Carbon Balance.
1. 75 FTP
LaForce Car
-9
Invalid Data
-3
2. Highway Cycle
LaForce Car
-6
-6
-6
3. Steady State Tests
LaForce Car
15 mph -12
-10
0
LaForce-Supplied
74 Hornet
-9
-4
-3
LaForce-Supplied
74 Hornet
-4
-3
-1
30 mph
-13
-13
-11
LaForce-Supplied
74 Hornet
+1
-7
+7
-4
-2
-3
Rented
74 Hornet
-15
- 6
No Data
No Data
Rented
74 Hornet
-3
-4
0
No Data
No Data
Rented
74 Hornet
-6
0
+4
-12
No Data
Invalid Data
-4
+4
-5
No Data
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41
Appendix H Continued
LaForce Car
LaForce-Supplied
74 Hornet
Rented
74 Hornet
40 mph
-13
-12
-15
-6
-5
-7
+12
-4
+4
-5
No Data
50 mph
-4
-7
-8
-3
-4
-1
-3
-4
+2
-5
No Data
60 mph
Invalid Data
-3
-4
Invalid Data
-1
0
-1
Invalid Data
+13
0
No Data
30 mph
No Load
No Data
-10
Invalid Data
-2
+12
+10
0
+14
-3
-1
No Data
See page 11 for discussion of the above data.
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