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The object of this paper is to present an overview of the procedure leading to the selection of suspension system pivot points, show how to resolve terrain and maneuver loads at the tire contact patch to the vehicles' structure, illustrate the modeling technique used for stress analysis of suspension system components, and illustrate a few examples of suspension system models used to aid in the solution of ride and handling problems.

The comparative dynamic response (acceleration, velocity, and crush) of two cars, differing in mass and structural characteristics and impacting head-on, is examined for various closing speeds and payloads through the use of a computer simulation model. Among other results, this analysis of the so-called vehicle mix problem shows the inherent limitations of “equivalent barrier impact” concepts in analyzing such impacts.

Multiple cyl engine tests demonstrated that lean methanol operation gave improved tail pipe emissions and better Btu efficiency than gasoline. The reductions in NOx emissions were particularly significant. Some loss in maximum power output was experienced, but the loss was less than that for gasoline operation at equivalent NOx emissions. This program was directed toward making the minimum number of engine modifications to simplify retrofitting of existing vehicles to utilize methanol.

Current national interest in alternative fuels has placed considerable emphasis on alcohols, mainly methanol and its blends with gasoline. Vehicle studies with methanol-gasoline and ethanol-gasoline blends showed that adding alcohol to gasoline without carburetor modifications decreased carbon monoxide emissions, volume-based fuel economy, driveability, and performance. Depending on the carburetor's air-fuel ratio characteristics, hydrocarbon and nitrogen oxide emissions and road octane are either increased, decreased, or not affected. These effects can be explained on the basis of changes in stoichiometry, energy content, combustion temperatures, and detonation resistance caused by the addition of alcohol to gasoline.

Comparative testing of pure methanol, methanol/water blends and isooctane in single-cylinder engines has demonstrated that through proper utilization of methanol's fuel-lean combustion characteristics it may be possible to reach CO emissions of the order of 0.1 percent and NOx emission levels of less than 100 ppm in the raw (undiluted) exhaust. Exhaust treatment to remove unburned methanol and partial oxidation products might be required. Concomitant with decreased emissions are specific energy consumption improvements estimated to be in the range of 26 to 45 percent better than achievable with current gasolines and the associated low compression ratio engines and emission control systems. These energy consumption improvements are obtained by virtue of efficient lean operation and by utilizing the high octane values of methanol/water blends at high compression ratios.

A study of methanol as an automotive fuel was conducted using a single-cylinder research engine, a 4-cylinder 122-CID (2,000 cc) engine, and an 8-cylinder 350-CID engine. Results showed that when using methanol as fuel, the single-cylinder engine could operate leaner than the multicylinder engines. This difference is attributable to air-fuel mixture maldistribution associated with the multicylinder engines. Steady-state fuel economy and emissions data are presented and discussed. Results indicate that fuel economy (on an energy input basis) using methanol fuel is about 5% improved as compared to gasoline fuel economy and with substantially lower nitrogen oxides emissions for methanol.

This paper† reviews the current status of work on the sodium-sulfur battery with emphasis on the ceramic electrolyte and container and electrode materials for the sulfur electrode. In. addition, test results are compared with results from cells which were identically constructed except that they were metal-free. Whereas problems still remain, it is concluded that no fundamental obstacle is known which would preclude the commercial development of the sodium-sulfur battery.

It has been successfully demonstrated that axle gear noise is greatly reduced with the addition of a simple and inexpensive device which can be mounted on either of the two side flanges of the final drive without special modifications. The addition of this device, with the resulting additional inertia mass, makes the driveline and its vibration nonsymmetrical with respect to the final drive. This has the effect of decreasing the vibration level of the hypoid gear itself, as well as changing the resonance frequency of the driveline. A theoretical proof is also given in which the approach is to treat the noise not as associated with the final drive itself, but as a vibration problem in the driveline.

In order for bevel and hypoid gears to function efficiently, it has been established that the two mating members must be maintained in close alignment under all operating conditions. Deflection tests were made on gear mountings to determine what happens to the relative positions of mating gear and pinion and what corrective measures are required in the gear mounting to bring the relative positions within acceptable limits (those relative displacements which will not severely impair the load-carrying capacity of the gears or result in noisy gears).

An accurate appraisal of gear tooth stresses is dependent upon knowledge of the deflection characteristics of the gear mounting as well as the details of gear geometry. For optimum load-carrying capacity it is most desirable to achieve as nearly uniform load and stress distribution as possible; and thus gear mountings should be designed to this end. The equations for effective face width and load distribution factor can be introduced into the basic gear tooth strength formulas to give more accurate stress values; in this paper bevel and hypoid gears are discussed in this context.

A new series of enviornmentally-sealed connectors has been developed for automotive use. They are presently being used on truck anti-skid brake control systems. These connectors prevent the entry of moisture and dirt, and are, at the same time, resistant to hydrocarbon fluids used in and around motor vehicles-such as gasoline, motor oil, transmission fluid, etc. The operating temperature is from -40°C-+105°C. Stamped tin-plated contacts are supplied on reels for semi-automatic termination. Two, three, and four pin connectors are presently available. Sealing boots for jacketed cable can be supplied. Special purpose Sure-Sealtm connectors are also being made to fulfill specific requirements.

Recreational Ecological Vehicle (REV) 74 was an intercollegiate All Terrain Vehicle (ATV) design competition organized by the Milwaukee and Cincinnati Sections of SAE. Students from six colleges built ATV's to compete May 30-June 1, 1974 at Michigan Technological University's Keweenaw Research Center test course. Competing categories of noise level, destructiveness to terrain and a 25 mile race over land and water are discussed from the viewpoint of the technical rules and as to the actual course involved with the competition. Michigan Tech designed and built a 4 wheel steer-4 wheel hydrostatic drive ATV for REV-74. This paper provides a detailed design description of the Michigan Tech vehicle along with a review of several production ATV designs and their specifications. Finally, a report of the results of REV-74 is presented.

Evaluation was made of the effects of plasticizer, wax, and high humidity on the peel strength of vulcanized chloroprene rubber bonded to primed steel with a polyurethane adhesive. Antiozone wax in rubber has a pronounced effect in reducing adhesion of the rubber to the adhesive. Dioctyl sebacate plasticizer in the rubber reduces bond strengths moderately. High humidity has a substantial deleterious effect upon the polyurethane adhesive and primer system used in this study.

The history and structure of the Recreational Ecological Vehicle Design Competition, REV-74, is discussed. In this competition, held at Houghton, Mich., several universities designed and constructed all-terrain vehicles which were evaluated in a series of test events. The University of Cincinnati's six-wheeled all-terrain vehicle is described in detail. Features included in the discussion are the vehicle's twin hydrostatic drive transmission, independent suspension, high-frequency muffler, and jet pump drive for water propulsion.

The Milwaukee and Cincinnati Sections of the Society of Automotive Engineers are commended for creating the Recreational Ecological Vehicle competitions. The Society should become more involved with relevant projects by encouraging its membership to establish and support similar events. The Industrial Design Dept. at Arizona State Univ. considers projects of this type sufficiently important to adopt them as the basis for a two semester classroom Design Project. For REV 74, this resulted in the design and construction of an ATV that had a six wheel hydrostatic drive, independent suspension, fore and aft combined steering, and a water propulsion system.

The description of a hydrostatic transmission system designed and built for a six wheel all-terrain vehicle is given. The transmission layout and components are described in detail. The drive train basically consists of a gasoline engine, two pumps, and six hydraulic motors, one for each wheel. The theoretical total horsepower required to get the maximum pressure, 3000 psi (20.7 MPa), and flow, 15 gpm (0.057 m3/min), capabilities of the two hydraulic systems comprising the transmission is 52.5 hp (39.1 kW). A description of the design and construction of the vehicle with the hydrostatic drive is also given. The vehicle will accommodate one passenger, weighs 725 lb (329 kg) empty and can achieve a top speed of almost 30 mph (48 km/h). The instrument panel includes gauges for monitoring the hydraulic line pressures, flowrates and oil temperatures under actual operating conditions. The results of an extensive testing program are given.

Blends of up to 20% methanol in gasoline were evaluated in both engine dynamometer and controlled vehicle tests, and in a 50,000 mile road test. Performance comparisons between methanol blends and base gasolines were made in vehicle driveability and vapor lock tendency, engine deposits and wear, fuel economy, exhaust emissions, compatibility with fuel system materials, and phase stability of the blends. Vapor lock tests in six 1974 cars strongly suggested that the vapor lock tendency of methanol blends is greater than would be predicted for gasolines having the same volatility characteristics. Cold start and warm-up driveability of two 1974 cars at 70°F depreciated as methanol concentration increased in base fuels of three volatility levels. These driveability data were found to correlate well, at a given methanol concentration, with fuel volatility characteristics described by means of a new fuel vaporization pressure technique.

A single cylinder engine was used to study the combustion and emission characteristics of methanol and indolene clear fuel. Measurements on ignition delays, combustion intervals, power, and exhaust emissions were made over a range of speeds, loads, and air-fuel mixture ratios (A/F). The results were used to determine the difference in relative power, efficiency and emissions between the two fuels. Relative to indolene, methanol exhibits faster overall burning rates, (shorter ignition delay periods and combustion intervals). At the same engine air flows and equivalence ratios, methanol produces more power than indolene. Fuel consumption with methanol is higher but the energy consumption rate is lower. NO emissions with methanol are generally lower; but, depending on equivalence ratio, CO and HC emissions are less than, equal to, or greater than those with indolene fuel.

As part of recent IIEC-2 activities, we have studied kinetics of ammonia formation to delineate engine conditions for best net NOx efficiency and to expand the choice of emission control systems. These studies have been carried out in the laboratory with exhaust gases generated by a pulse flame generator and rhodium containing catalysts. Catalyst selectivity, NH3/N2 was found to vary linearly with the CO/O2 ratio in the exhaust gas and with the reciprocal of the space velocity. The effects of temperature and input NOx levels are more complex: Selectivity shows a maximum in the range of 750-1300°F and increases gradually as the NOx level is decreased from 800 - 100 ppm. Based on these results a mechanism is proposed for ammonia formation and a triple-catalyst system is suggested for increasing net NOx efficiency.

A number of approaches to the development of low emissions engines have been reported in the literature. Many of these approaches, however, have reduced emissions by retarding ignition timing. This increases exhaust gas temperatures for more complete HC oxidation in the exhaust system but results in a fuel economy penalty. Previous studies by the authors indicated that NOx can be effectively reduced with judicious use of EGR. While this may result in increased HC emissions, under some conditions it also can result in improved fuel economy. The data reported in this paper demonstrate that the use of EGR is capable of reducing NOx emissions and octane number requirements while improving fuel economy. Any resultant increase in HC emissions can be controlled with an efficient HC/CO oxidation catalyst.