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High output turbocharged diesel engines require efficient air delivery systems with high pressure ratio, broad range and surge-free compressors of very high efficiency. Similarly, high efficiency turbines with variable stators will be needed to maintain high turbine speed at times when engine speed and airflow are low. The turbocharger that evolved in a U.S. Army TARADCOM sponsored program to meet these goals has a backward curved centrifugal compressor with a wedge type moveable vane diffuser for surge control and a radial inflow turbine with individually pivoted nozzle vanes for inlet flow area control. After several design iterations and bench tests, extensive engine tests were conducted to demonstrate the substantial improvements in diesel engine performance that are attainable with these turbochargers.

This paper reviews active work being carried out in Europe. A newly developed range of I.C.'s is described. Test panels using Vacuum Fluorescence, DC Electroluminescence, and Light Emitting Diodes are being built into display modules and fitted to vehicles for evaluation. The present state of development with DC Electroluminescence is described, including combined instrument panels which can be made now. The relative merits of other available systems particularly relevant to economics are compared. A range of digital clock variants, including timers, and the integration into tachometer and instrument panels leading to general digital instruments are also described. Also covered are the special problems of trip and total odometers and the available solutions. Finally the paper covers the addition of microprocessors to the control electronics adding the possibility of other functions such as diagnostic and message panels.

The present performance capabilities of liquid crystal displays relative to automotive requirements is reviewed. Fundamental material limitations to LCD performance will be discussed. Operating characteristics that may be anticipated in the next two to five years, in regards to such parameters as operating voltage, operating and storage temperatures, humidity resistance, response time, viewing characteristics, color and display styling will be treated. In addition, examples of the use of LCDs for portrayal of analog and vectorgraphic information will be presented.

The advances being made in the liquid crystal technology are now enabling the liquid crystal display (LCD) to be used in the hostile environment of the automobile. The liquid crystal technology advances, combined with their known qualities, aesthetics, and ever-increasing potential, make them a candidate for the display technology of the near future. This paper reviews the current “state-of-the-art” of LCD's and discusses how electronics may be used to solve many of the practical problems of integrating LCD's into instrumentation systems. This paper concentrates on the practical issues that must be addressed when considering the LCD technology for automobiles.

A new type of thin film light source has been developed. It's most interesting feature is voltage control of the emission color. The underlying physical principles give new insight into light producing mechanisms.

Vacuum fluorescent displays offer the instrument engineer a wide range of design options. Close liason between the instrument engineer and the display engineer is an important part of the design cycle. Various specification proposals are made and a new design proposal is introduced.

A new microcomputer family simplifies the system design of display panels and dashboards by minimizing the parts count. Both high voltage and low voltage drive capability together with analog inputs and outputs enable efficient human communication while simultaneously performing system control and computations.

Digital instrument cluster system designs can be optimized through the use of single-chip microcomputers except when the disadvantages of their use become severe. A new microcomputer design eliminates many of the drawbacks while preserving the economic and space-saving features of previous single-chip microcomputers.

New fuel efficient 7.5″ (190.5 mm) and 8.5″ (213.9 mm) cast center axles have been introduced in the 1979 Ford and Mercury full-size cars. The design, development and manufacturing of these axles contain several new and interesting features which offer maximum manufacturing flexibility and improved reliability.

The ambient light levels incident on electronic displays located in the instrument panel can be sufficiently bright to impair their readability, unless optical filtering techniques are employed. The aim of this study was to develop the experimental procedures and associated instrumentation to objectively and quantitatively measure the readability of a given electronic display - optical filter combination. Readability was quantified through the two criteria of recognition accuracy and response time. The effects of display parameters such as character size, luminance, and background color on the accuracy and response time data, and subsequent filter choice, were evaluated.

A flywheel to manage energy between a prime mover and a load has been used in many engineering applications. Automotive applications, however, pose a number of difficult problems which can be overcome only with proper design. Substantial mileage and performance improvements while meeting emission constraints can then be accomplished with the concept. An experimental flywheel car has been designed and built at the University of Wisconsin that has demonstrated a mileage improvement of about 50% over a corresponding production vehicle on the EPA/FUDC. With continued research and development gains of 100% appear feasible.

THE SINGLE RAIL SHIFT OVERDRIVE (SROD) 4-speed manual transmission was designed and developed to incorporate the reliability and durability characteristics of a totally enclosed, non-adjusting, single-rail shift mechanism while maintaining the conventional 4-speed shift pattern. An additional objective was to optimize fuel economy with 3.3L, 4.1L and 5.0L engines while maintaining acceptable vehicle performance, acceleration and vehicle driveline noise, vibration and harshness. The design procedures used to obtain the design objective and to satisfy performance requirements are reviewed.

A digital transmission shift schedule control has been developed which measures throttle position and vehicle speed to determine the proper gear ratio based on preprogrammed upshift and downshift schedules. Transmission pleasability was evaluated for various degrees of resolution for these two primary input variables. Five- and six-bit vehicle speed and three- and four-bit throttle position resolutions were tested. Throttle position was measured with an experimental variable reluctance (variable frequency oscillator) device, located above the throttle pedal; vehicle speed was measured by a magnetic pickup from a toothed wheel on the transmission output shaft. The electronic control system has been evaluated for over 4000 miles under city, highway, sea level and high altitude conditions.

With the big gains in automobile fuel economy already accomplished, primarily with off-shelf technology, further improvements above that expected by further downsizing will now require advanced technology. One area in which advancing the state of the art may not only benefit fuel economy but preserve drive-ability is in the fluid dynamic performance of torque converters. While lockup clutches may preclude the need for higher converter efficiency, improved performance in the primary gears where lockup is inhibited would still benefit fuel economy. The gains, however, would be less, but driveability would be improved by the higher coupling efficiency. Detailed fluid dynamic investigations were performed on a three-element torque converter. These investigations were based on computer solutions that have been successfully applied in the design of gas turbines. Using a numerical solution, surface velocities were computed along the reactor blade based on a two-dimensional flow field.

This paper discusses current powertrain matching methodology and its applications. Modular computer programs, which model each component of the vehicle/powertrain system, simulate the vehicle over specified driving cycles to project fuel economy and performance. Fuel economy opportunities due to better powertrain matching are discussed, including optimum engine sizing, torque converter matching, transmission gear ratio spacing and shift scheduling, axle ratio and vehicle weight effect. An emission projection technique utilizing time weighted engine speed/load points generated either by experiment or by analytical models is used to quantify fuel economy/emissions trade-offs.

In developing high speed swirl supported direct injection diesel engines it has been a general experience that different engine results (performance, smoke and emission) may be obtained when using different intake port designs, although the swirl numbers (stationary flow test rig) of the different ports were identical. Therefore, an in-cylinder flow investigation under motoring conditions using hot wire anemometry was performed for three different inlet port designs having the same swirl number. Special emphasis was drawn on the engine design parameters being as close as possible to reality. Thus, the flow investigation and the engine tests were carried out at a typical compression ratio of 18 : 1 using a standard combustion bowl in the piston as well as produceable inlet ports. All flow measurements were carried out under motoring conditions covering the speed range from 1100 to 2400 rpm.

The lower efficiency of the indirect-injection diesel engine, with respect to the direct injection type, is due to additional heat transfer from the combustion chamber, gas pumping between chambers, later injection timing and a different burning rate schedule. The paper describes a project to isolate and quantify these reasons for low efficiencies, using a mathematical model, supported by experimental verification. The model is based on a two-zone system (main and pre-chamber), with component models for heat transfer, gas flow through the passage etc. Experimentally derived heat release schedules in main and pre-chamber are used. It is shown that for a 0.1 m bore engine, with a Ricardo Comet Vb pre-chamber, the different burning rate schedule is the major contribution to the difference in efficiency, with injection timing and gas pumping being the least significant.

A continuously variable transmission with an overall ratio of 6 may be worked out on a purely hydrostatic basis. High power to weight ratio hydraulic pump and motors can be designed to avoid bulk and weight penalty. Mass production can be used. Materials and manufacturing processes are not more sophisticated than in conventional automobile manufacturing. Although lower than in gear transmission, efficiency of the hydrostatic transmission is suitable for automobile use.

Starting from a classification of car transmissions and from the manufacturers requirements, especially for fuel savings, the potential advantages of continuously variable transmissions permitting to associate low engine RPM with high vehicle speed, are shown. The control of the engine, transmission and clutch to reach a given optimum, is explained. Here are given results of simulation or testing of vehicles equipped with a Renault hydrostatic prototype transmission, a 2-mode hydromechanical transmission and a Van Doorne prototype Transmatic. Highway fuel economy trends are quantified in case of substitution of the conventional S.I. engine for Diesel and/or turbocharged engines.

The more detailed the performance specifications for diesel engine are defined, the more difficult is the task to find the best possible compromise in applying a fuel injection system. This paper outlines in detail the strategy, how the objectives can be achieved within a reasonable time frame. The application of this strategy is demonstrated using actual results of a study based on optimization of exhaust emissions and fuel economy.