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This paper discusses simplified lumped parameter thermal modeling of power train components. In particular, it discusses the tradeoff between model complexity and the ability to correlate the predicted temperatures and flow rates with measured data. The benefits and problems associated with using a three lumped mass model are explained and the value of this simpler model is promoted. The process for correlation and optimization using modern software tools is explained. Examples of models for engines and transmissions are illustrated along with their predictive abilities over typical driving cycles.

For designing new products or developing new specifications, the reliability performance of systems and components experienced by the customer provides invaluable information for the engineer. This information, not only provides for the visibility of reliability requirements, but also an awareness of potential degradation of the systems and components during its life cycle. In this paper, a method is presented for predicting vehicle system and component reliability from vehicle fleet repair data. This method combines sampling stratification, computer data analysis and statistical modeling techniques into a reliability analysis procedure to provide reliability prediction. Specifically, published vehicle fleet data was used to provide the basis for predicting the vehicle system and component reliability at any mileage level.

This paper discusses the feasibility and issues associated with integrating a consumer off-the shelf product into a vehicle. For this evaluation, we selected a handheld personal computer (HPC), cellular telephone and modem to integrate with the vehicle audio, climate and system controls. Connectivity between the HPC and the vehicle is established by the use of the standard infrared serial data link that comes with the HPC. Connectivity outside the vehicle uses a cellular telephone for voice and a cellular digital packet data (CDPD) modem for data. This system is built into the Dodge ESX-2 hybrid powered concept vehicle for demonstration.

The rapid growth of information technology has the potential to affect many of the reasons why people drive. The Internet is arguably the most significant recent milestone in the growth of information technology. This paper examines the ways Internet communication might affect the travel experience by a) eliminating traditional reasons for personal travel, b) providing new reasons, c) changing the balance between personal and freight travel, and d) changing trip length distribution. Changes of the types listed could affect the product demand "mix" for electric, hybrid-electric and fuel cell vehicles being developed.

The reliability of an electronic sensor in the automotive applications is assessed using data from Fleet Test and proving ground Vehicle Endurance test. These nonfailure data are multiply censored at different mileage. Reliability analysis of data with no failure is rarely discussed in most reliability literature. This paper applies the Weibull maximum likelihood analysis based on known values of the Weibull shape parameter to extract useful reliability information. The well-known Weibayes and Weibest methods are subsets of the discussed approach. The sensitivity of the change of reliability levels over a range of Weibull shape parameter values is also examined in our case. The Huang-Porter (1991) approach of obtaining a reliability lower bound regardless of the Weibull shape parameter values is also applied and its potential of practical application is discussed. Practical limitations of all methods are discussed.

Higher horsepower per liter engines have put more demand on the crankshaft, often requiring the use of forged steel. This paper examines cost reduction opportunities to offset the penalties associated with forged steel, with raw material and machinability being the primary factors evaluated. A cost model for crankshaft processing is utilized in this paper as a design tool to select the lowest cost material grade. This model is supported by fatigue and machinability data for various steel grades. Materials considered are medium carbon, low alloy, and microalloy steels; the effects of sulfur as a machining enhancer is also studied.

A running loss test procedure has been developed which integrates a point-source collection method to measure fuel evaporative running loss from vehicles during their operation on the chassis dynamometer. The point-source method is part of a complete running loss test procedure which employs the combination of site-specific collection devices on the vehicle, and a sampling pump with sampling lines. Fugitive fuel vapor is drawn into these collectors which have been matched to characteristics of the vehicle and the test cell. The composite vapor sample is routed to a collection bag through an adaptation of the ordinary constant volume dilution system typically used for vehicle exhaust gas sampling. Analysis of the contents of such bags provides an accurate measure of the mass and species of running loss collected during each of three LA-4* driving cycles. Other running loss sampling methods were considered by the Auto-Oil Air Quality Improvement Research Program (AQIRP or Program).

This study analyzes the vibration characteristics of the valve train of a 2.0L SOHC Chrysler Corp. Neon engine over a range of operating speeds to investigate and demonstrate the advantages and limitations of various dynamic measurements such as displacement, velocity, and acceleration in this application. The valve train was tested in a motoring fixture at speeds of 500 to 3500 camshaft rpm. The advantages of analyzing both time and frequency domain measurements are described. Both frequency and order analysis were done on the data. The theoretical order spectra of cam displacement and acceleration were computed and compared to the experimental data. Deconvolution was used to uncover characteristic frequencies of vibration in the system. The theoretical cam acceleration spectrum was deconvolved from measured acceleration spectra to reveal the frequency response function of the follower system.

Typical sand-casting techniques have been shown to be inappropriate in pouring particulate reinforced aluminum metal matrix composite (Al-MMC) castings. New gating/risering configurations were necessary to produce castings of acceptable soundness. Several automotive components, including brake rotors, cylinder liners and camshaft thrust plates, were prepared using special techniques. Initial durability test results of several Al-MMC prototype components are presented.

To evaluate and refine interior architecture of the new Dodge Ram pickup truck three years before production, a road worthy interior package validation buck was built using a fiberglass body shell. Molds for the shell were made using CAD/CAM techniques. Advanced CAD/CAM techniques were used to build the interior buck of a subsequent model from individual panels molded in carbon fiber. This buck also included inner structural panels and interior trim components taken from CAD data. For this and subsequent new vehicle programs, refinement of construction techniques allows the bucks to serve as aids in product design and manufacturing feasibility studies.

Chrysler Corporation has developed an 8.0-liter engine for light truck applications. Numerous features combine to produce the highest power and torque ratings of any gasoline-fueled light truck engine currently available while also providing commensurate durability. These features include: a deep-skirt ten-cylinder 90° “V” block, a Helmholtz resonator intake manifold that enhances both low and mid-range torque, light die cast all-aluminum pistons for low vibration, a unique firing order for smooth operation, a “Y” block configuration for strength and durability, a heavy duty truck-type thermostat to control warm up, and a direct ignition system.

Chrysler Corporation's Jeep and Truck platform implemented a new design and prototype process for the body-in -white of a new pickup truck. A team approach achieved concurrent body design, stamping die design, assembly process development, and assembly tooling development. The first domestic US industry use of a 100% electronic design and release system was instrumental in the process. The new process produced a prototype body-in-white on time at 95 WBVP (weeks before volume production) with the highest level of production-intent components ever achieved within Chrysler at this stage of development.

This paper presents the development of a test procedure for evaluation of inadvertent deployment of air bags. The methodology and early development of the procedure is discussed along with additional criteria thought to be required for trucks and sport utility vehicles. Tests conducted address severe off-road use in relation to air bag sensing systems. Data is collected from accelerometers. After worst case test conditions are identified (examples include rough road, snow plowing and jerk towing events), the data is analyzed and comparisons for design decisions can be made.

A new 3.5 liter, 60 degrees V6 engine has been designed specifically for Chrysler's 1993 MY line of mid-size sedans - Dodge Intrepid, Eagle Vision, Chrysler Concorde and New Yorker. This new engine features many new components for enchanced performance. The cylinder head has a single overhead cam, four valve-per - cylinder design. The intake system is a cross-flow design equipped with dual throttle bodies, and the manifold also incorporates a vacuum operated tuning valve that increases the mid-range torque of the engine. A windage tray is used on every engine to reduce drag on the rotating components within the crankcase. Dual knock sensors (one per cylinder bank) are used to take advantage of the aggressive spark advance and high compression ratio. The engine also utilizes a plastic, helical, water pump impeller that contributes to low parasitic power losses. The engine incorporates many components and features to ensure durability.

Most United States vehicle assembly plants produce significantly more automatic transmission equipped vehicles than manual transmission vehicles. Assembling these two vehicles on a common production line can create complexity problems. This paper describes the design and development of a pre-assembled manual transmission clutch and flywheel modular assembly which reduces most of these problems. This assembly is used on the 1993 model year mini-van with a 2.5L four cylinder engine. This modular clutch system utilizes the same starter ring gear carrier (driveplate) used on automatic transmission equipped vehicles. It pilots into the crankshaft similar to the automatic transmission torque converter. It is balanced as an assembly which results in a lower system imbalance. A significant system piece cost saving, in comparison with today's competitive market, was achieved.

Most of the current fuel supply specifications, including the key parameters in the transient fuel control strategies, are experimentally determined since the complexity of multiphase fuel flow behavior inside the intake manifold is still not quantitatively understood. Optimizing these specifications, especially the parameters in transient fueling systems, is a key issue in improving fuel efficiency and reducing exhaust emissions. In this paper, a model of fuel spray, wall-film flow and wall-film vaporization has been developed to gain a better understanding of the multiphase fuel-flow behavior within the intake manifold which may help to determine the fuel supply specifications in a multi-point injection system.

The J1850 bus requirements promote an unique and well characterized physical layer behavior developed through the learning curve of previous multiplex solutions. Design requirements such as: 1) Reliably interconnecting all of the vehicle's most complex modules, 2) Consistently withstanding the vehicle's harsh environment, and 3) Meeting SAE's functionality requirements, were all a formidable task to achieve. This paper will highlight the path taken to achieve a J1850 Bus interface which successfully met all of the design and functional goals. Chrysler's C2D insights will be discussed and related to goals for J1850. Other design considerations will also be discussed such as EMC issues, custom test equipment, and vehicle and component testability. In turn, silicon processes with special structures and topologies will be discussed relating the specific design with the needed electrical behavior. The HIP7020 J1850 BUS TRANSCEIVER I/O for MULTIPLEX WIRING accomplishes these requirements.

MIL 3's OPNET simulator was used to model Chrysler's J1850 bus. Modeled were both J1850 bus characteristics and those portions of control modules (e.g., the engine controller) which communicate on the bus. Current Chrysler control module algorithms and proposed Chrysler J1850 message formats were used to design the control module models. The control module models include all messages which are transmitted at fixed intervals over the J1850 bus. The effects of function-based messages (e.g., messages to be transmitted on a particular sensor or push-button reading) on system load were investigated by transmitting an additional message with a fixed, relatively high priority at 50 millisecond intervals.

The UBHC emissions during cold starting need to be controlled in order to meet the future stringent standards. This requires a better understanding of the characteristics of the time resolved UBHC signal measured by a high frequency FID and its phasing with respect to the valve events. The computer program supplied with the instrument and currently used to compute the phase shift has many uncertainties due to the unsteady nature of engine operation during starting. A new technique is developed to measure the in-situ phase shift of the UBHC signal under the transient thermodynamic and dynamic conditions of the engine. The UBHC concentration is measured at two locations in the exhaust manifold of one cylinder in a multicylinder port injected gasoline engine. The two locations are 77 mm apart. The downstream probe is positioned opposite to a solenoid-operated injector which delivers a gaseous jet of hydrocarbon-free nitrogen upon command.

Vacuum insulation and phase-change thermal storage have been used to enhance the heat retention of a prototype catalytic converter. Storing heat in the converter between trips allows exhaust gases to be converted more quickly, significantly reducing cold-start emissions. Using a small metal hydride, the thermal conductance of the vacuum insulation can be varied continuously between 0.49 and 27 W/m2K (R-12 to R-0.2 insulation) to prevent overheating of the catalyst. A prototype was installed in a Dodge Neon with a 2.0-liter engine. Following a standard preconditioning and a 23-hour cold soak, an FTP (Federal Test Procedure) emissions test was performed. Although exhaust temperatures during the preconditioning were not hot enough to melt the phase-change material, the vacuum insulation performed well, resulting in a converter temperature of 146°C after the 23-hour cold soak at 27°C.