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This paper introduces for the first time a fully connectorized passive optical star for use with plastic optical fiber that addresses all automotive application requirements. A unique mixing element is presented that offers linear expandability, uniformity of insertion loss, and packaging flexibility. The star is constructed of all plastic molded components to make it low cost and produceable in high volume and is single-ended to facilitate vehicle integration. The star is connectorized to facilitate assembly into the vehicle power and signal distribution system.

The overall vision of this project was to develop a new technology that will be an enabler to reduce design and development time of HVAC systems by an order of magnitude. The objective initially was to develop a parametric model of an automotive HVAC Windshield Defrost Duct coupled to a passenger compartment. It can be used early on in the design cycle for conducting coarse packaging studies by quickly exploring “what-if” design alternatives. In addition to the packaging studies, performance of these design scenarios can be quickly studied by undertaking CFD simulation and analyzing flow distribution and windshield melting patterns. The validated geometry and CFD models can also be used as knowledge building tools to create knowledge data warehouses or repositories for precious lessons learned.

While long-range planning is important to any organization, because of the constant turnover of volunteer leaders, a long-range strategic plan is crucial for maintaining continuity in a non-profit organization. SAE's strategic planning process resulted in a plan, evaluated and revised annually, which outlines the purpose, missions, and goals of the Society and describes action plans and steps necessary to achieve those goals. SAE's exceptional growth in all areas during the last ten years-for example, membership has grown from 37,000 in 1980 to 58,000 today-is evidence of the success of the process and the plan.

This paper discusses an analytical technique for computing the failure rate of steel springs used in automotive part applications. Preliminary computations may be performed and used to predict spring failure rates quickly at a very early stage of a product development cycle and to establish program reliability impact before commitment. The analytical method is essentially a combination of various existing procedures that are logically sequenced to compute a spring probability of failure under various operational conditions. Fatigue life of a mechanical component can be computed from its S-N curve. For steels, the S-N curve can be approximated by formulae which describe the fatigue life as a function of its endurance limit and its alternating stress. Most springs in service are preloaded and the actual stress fluctuates about a mean level. In order to compute an equivalent alternating stress with zero mean, an analytical method based on the Goodman Diagram is used.

Defining or sizing the basic components in a vehicle brake system is done to satisfy specific requirements such as vehicle stopping distance, pedal travel and effort; braking efficiency as well as thermal considerations, cost, and packaging. This paper presents a flow-down method for computing brake system design parameters directly from those requirements. Relationships are also developed that enable the designer to understand trade-offs between requirements and system parameters.

The development and application of a traction control Kodiak and GMC TopKick are explained. Most traction systems use engine management to enable traction control, while the adaptive braking system can provide traction assist for either gas or Diesel powered vehicles from 14,000 lbs. to 33,000 lbs. GVW. The performance driven criteria that established the design requirements and the development of a new product to meet these objectives are discussed. Both the vehicle manufacturer and the traction controller supplier provided these criteria. The basic ABS and traction control hydraulic schematics will be described as they apply to the vehicles. The results of the development program will be compared to the criteria used to establish the goals, and the benefits of the traction control system will be discussed.

The Cadillac Electronic Climate Control heating and air conditioning system provides automatic control of the passenger compartment temperature. It utilizes a microcomputer to control the operation of electrical, mechanical and vacuum components that regulate the amount and temperature of air delivered into the car to maintain the “customer set” comfort level. The first step in the evolution of this new system was to define the performance requirements. With this established, the system was then designed, tested and developed in the laboratory and on the road until this desired performance was achieved.

The use of regrind acrylonitrile-butadiene-styrene (ABS) for automotive parts and components results in two types of financial savings. The first is the shared monetary savings between General Motors and the molder for the difference in the virgin resin price versus price of the ABS regrind. The second is a societal energy savings seen in the life cycle of virgin ABS versus reground ABS. An added benefit is the preservation of natural resources used to produce virgin ABS.

This study examined whether the effect of subsidiary tasks on driving performance can be predicted from stationary (static) testing. Alternative methods for assessing the performance of drivers during their use of in-vehicle information systems were examined. These methods included static testing in stationary vehicles, as well as dynamic, on-road testing. The measures that were obtained from static tests were evaluated in terms of how well they could predict measures obtained from driving performance during on-road testing (which included concurrent use of secondary information systems). The results indicated that measures obtained in static test settings were highly correlated with corresponding measures obtained from on-road performance testing.

As component and systems sophistication in both cars and trucks increase, improved diagnostic capabilities are required to assure proper and expedient serviceability. Replacement of electrical modules, starter motors, carburetors, fuel injectors and even whole engines or transmissions is encouraged by high labor costs and continued vehicle mobility mandates. The remanufacturing business has grown and components previously discarded now provide valuable core elements to feed the industry. To achieve efficient utilization of capital, equipment and labor, remanufacturers must estimate when this supply of core elements will be available and plan their production schedules accordingly. In order to properly service private individuals and commercial fleets, minimize vehicle downtime and reduce life cycle costs, adaptation of available analytical tools must be made.

The primary objective of Central Port Fuel Injection is to be a low cost multi-point fuel injection system with the additional attributes of compactness, packaging flexibility, and reliability. Performance of this fuel system closely resembles that of a simultaneous multi-point fuel injection system in flow control, dynamic range, cylinder-to-cylinder distribution, idle quality, transient response, and emissions. The system provides significantly improved performance in the areas of hot fuel handling, cold startability, vacuum and voltage sensitivity and system noise. This performance comes at a significant cost savings and greater packaging and targeting flexibility over a conventional multi-point fuel injection system.

This paper describes the hardware execution of the front and rear suspensions of the all new 1997 Chevrolet Corvette. Topics covered include: alternative design trade-off, mass optimization, alignment and trim, structural interfaces, shared components, component design and a review of the overall design of the front and rear suspensions. Two case studies are detailed for the front upper and rear lower control arms. The systems engineering process used for suspension design is described throughout the paper.

Fully Flexible Valve Actuation (FFVA) systems provide maximum flexibility to adjust lift profiles of engine intake and exhaust valves. A research grade electro-hydraulic servo valve based FFVA system was designed to be used with an engine in a test cell to precisely follow desired lift profiles. Repetitive control was chosen as the control strategy. Crank angle instead of time is used to trigger execution to ensure repeatability. A single control is used for different engine speeds even though the period for one revolution changes with engine speeds. The paper also discusses lift profile extension, instantaneous lift profile switching capability and built-in safety features.

Today's world places increased emphasis on society's members to know more, to do more, to see more. Increasingly, information is thrown to the consumer that he/she has to process almost continually, regardless of their surroundings. Due to this heightened need, the customer is becoming increasingly perceptive of their vehicle surroundings, expecting their vehicle to be an extension of their home and/or office, to assist in getting things done in an environment that is as convenient and comfortable as their primary workplace. Similarly, there is also increased emphasis on vehicles to be styled so that they are visually appealing, so that all the parts work as a whole to make the environment as enjoyable as consumers' most pleasant surroundings outside the vehicle.

Free form fabrication, or rapid prototyping as it is commonly known, is the creation of a physical entity, directly from numerical description, using an additive process. The mathematical data used is typically in the form of a 3D CAD file, but it may also be obtained from a reverse engineering process. This paper presents a review of three of the leading FFF (free form fabrication) systems which are commercially available. Time constraints will allow us to describe only three of these products. Although this does not do justice to a technology where there are more than 30 different systems in various stages of development, these examples represent the vast majority of machines which are in the marketplace today.

FIGURE 1 The 200 HP high performance 4.3L Vortec V6 engine has been developed to satisfy the need for a fuel efficient performance powerplant in the General Motors small truck platforms. Marketing requirements included strong low and mid range torque, relatively high specific power, smoothness and noise comparable to the best competitive six cylinder engines, excellent driveability, and a new technology image. Maintaining the 4.3L engine record of high reliability and customer satisfaction was an absolute requirement. Fuel economy and exhaust emission performance had to meet expected customer and legislated requirements in the mid 1990's.

The purpose of this paper is to provide an overview of the process of selection, development and approval of General Motors original equipment TPC passenger car tires. We have attempted to minimize detail in each specific area, but intend to provide a general comprehension of the thought processes involved and the procedures used to select the proper tire size and type for a vehicle. We will then describe the tire performance criteria involved in the overall development and approval process and will subsequently consider tire noise requirements in somewhat greater detail. The paper will conclude by describing the General Motors Tire Performance Criteria (TPC) System, which is a documentation of the General Motors Tire Performance requirements and test procedures.

The Paint Technology Globalization effort is recognized as an important step of accomplishing the leveraging of worldwide resources of both engineering and purchasing in order to improve General Motor's competitiveness. The process used, the benefits derived, the current status of the effort, and the expected results (deliverables) are discussed. These include common materials, processing, and equipment paint specifications to be included in purchasing bid packages.

A search for methods of switching a proposed three beam headlight system led to the evaluation of 41 possible schemes. Human factors criteria reduced the original 41 to three systems which were tested in a laboratory with a broad range of subjects. Recordings of practice trials, learning trials, and the responses to visual cues projected on a screen were analyzed. The same test procedure was also used to compare three alternative ways of switching conventional two beam headlight systems. Summary data is presented for the six systems tested grouped by test subject age, sex, and driving experience. The most pronounced difference observed was in the subjective preference rating among two beam switching systems. All systems tested resulted in remarkably few learning and practice trials. Small differences were recorded among systems in operational response time.

From November 1970 through August 1971 an extensive program of static and dynamic air cushion inflation tests utilizing human volunteers was conducted at Holloman Air Force Base, New Mexico, sponsored by the Department of Transportation. Forty-one full cushion deployment static firings were made, with air cushion hardware and seating buck environment designed by General Motors. The static series was followed by 35 dynamic sled firings of human volunteers, beginning at 8.6 g (15.1 mph) and culminating at 21.7 g (31.5 mph). A major objective of both the static and dynamic test series was to identify changes in air-cushion design found necessary to improve its protective capability for human beings. Because of the severity of cushion deployment, one modification was made following the initial static tests: The orifice diameter size of the bag inlet was reduced from 1.0 to 0.6 in to diminish the rapidity of bag inflation. This modification proved effective in the dynamic series.