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Back to the non Flex Fuel vehicles, the knock control system was designed and calibrated to absorb differences between engines (mainly compression ratio) and to protect the engine against knock damage (a correction up to 4 degrees BTDC was usually enough). But now, two new variables get in the scene: Flexible Fuel strategy, working from E22 to E100 (all blends in between) and small displacement (1.0 liter) high compression ratio engines. In this new scenario the system must be capable of correcting all spark advance differences, once knock control system acts as a safety feature, protecting the engine even if the fuel learning shows some deviation. In addition to that, we have the compression ratio variation between minimum and maximum limits. Since the engine is small (as well its combustion chamber), each tenth of a millimeter difference during manufacturing process, results in an important final compression ratio variation.

Since the appearance of the first flexible fuel vehicle back in 2003, many improvements have been done in order to deliver a more reliable and more efficient engine package. The increase in compression ratio is one of the mechanisms used in performance pursuit and to guarantee the engine durability meeting fuel economy requirements, running with fuels from regular E22 to E100 under high compression, many challenges were faced. The pre-ignition running at low engine speeds and mid to high loads had to be controlled, maintaining a reasonable driveability. Increasing the engine speed across its useful band, a special knock event could occur. It is special because results in peak pressures up to 15.000 kPa, named “single strong knock” and is present mainly at highest closed-loop load operation. In addition of that, design limitation was the cause for cylinder #04 low sensitivity. This characteristic narrowed the spark correction band resulting in destructive knock activity.

Basic automotive steering wheel armature design has been largely unchanged for years. A cast aluminum or magnesium armature is typically used to provide stiffness and strength with an overmolded polyurethane giving shape and occupant protection. A prototype steering wheel armature made from a unique recyclable thermoplastic eliminates the casting while meeting the same stiffness, impact, and performance criteria needed for the automotive market. It also opens new avenues for styling differentiation and flexibility. Prototype parts, manufacturing, and testing results will be covered.

OEM and Tier One integrated suppliers are in constant search of cockpit system components that reduce the overall number of breaks across smooth surfaces. Traditionally, soft instrument panels with seamless airbag systems have required a separate airbag door and a tether or steel hinge mechanism to secure the door during a deployment. In addition, a scoring operation is necessary to ensure predictable, repeatable deployment characteristics. The purpose of this paper is to demonstrate the development and performance of a cost-effective soft instrument panel with a seamless airbag door that results in a reduced number of parts and a highly efficient manufacturing process. Because of the unique characteristics of this material, a cost-effective, lightweight solution to meet both styling requirements, as well as safety and performance criteria, can be attained.

To determine what effect (measured in haze), UV exposure has on polycarbonate inner lenses (coated and uncoated), when positioned behind qualifying (UV absorbent) and non-qualifying (UV transmitting) outer lens materials (clear and red). Plastic inner lenses are those covered by another material and are not exposed directly to sunlight.

A model has been developed and implemented at GE Plastics that predicts a material's color shift when weathered. The material's color shift is due to the summation of color shifts from each individual component. By individually measuring the change in each component's optical coefficients upon weathering and using a multiple light scattering model, one can predict the color shift of a material composed of mixtures of these components. The model has been shown to have a standard deviation of 0.4 to 0.9 when predicting color shifts E*, for PC-polyester copolymers, ABS, and ABS/PC blends using an automotive exterior test, SAE J1885, ASTM D 4674, and ASTM D 4459.

Current accelerated weathering protocols such as SAE J1960 or ASTM G26 do not provide reliable, predictive results for engineering thermoplastics. Correlation factors among resin types and even different colors of a single resin have variations that are 60-100% of the mean at the 95% confidence level, making these tests useless for lifetime prediction or even reliable ranking of materials. We have developed improved conditions using CIRA/sodalime-filtered xenon arc, a more rain-like water spray, and occasional sponge-wiping of the samples. The data for gloss loss and color shift agree very well with Florida data giving a correlation factor of 3100±680 kJ/m2 (at 340 nm) per Florida year at the 95% confidence level. The acceleration factor is 7.6x.

In the engine management systems field, there is lack of sensors locally built and available for sale in Brazil. Therefore, many auto parts companies have to import them affecting directly the final products costs (technology know-how/development costs, import taxes and other material handling/custom related costs). This paper was motivated to study an alternative for a simple, cheaper and locally made throttle position sensor. The choose of this part was because the fact that it is one of the most expensive in the throttle body bill of. For developing this new alternative, it was used a tool called value analysis and value engineering. The outcome of this study was a throttle position sensor function integrated to the throttle body manufacturing line with the advantages that 100% components can be locally purchased, improved robustness against humidity and component quantity reduction by 40%. Therefore achieving more value added.

This paper will discuss, compare, and contrast current materials, designs, and manufacturing options for fuel filler doors. Also, it will explore the advantages of using conductive thermoplastic substrates over other materials that are commonly used in the fuel filler door market today. At the outset, the paper will discuss the differences between traditional steel fuel filler doors, which use an on-line painting process, and fuel filler doors that use a conductive thermoplastic substrate and require an in-line or off-line painting process. After reviewing the process, this paper will discuss material options and current technology. Here, we will highlight key drivers to thermoplastics acceptance, and look at the cost saving opportunities presented by the inline paint process option using a conductive thermoplastic resin, as well as benefits gained in quality control, component storage and coordination.

The history behind Polymer Class “A” Body Panels for automotive applications is very interesting. The driving factors behind these applications have not changed significantly over the past sixty years. Foremost among these factors is the need for corrosion and dent resistance. Beginning with Saturn in 1990, interest in polymer body panels grew and continues to grow up to the present day, with every new global application. Today, consumers and economic factors drive the industry trend towards plastic body panels. These include increased customization and fuel economy on the consumer side. Economic factors such as lower unit build quantities, reduced vehicle mass, investment cost, and tooling lead times influence material choice for industry. The highest possible performance, and fuel economy, at the lowest price have always been a goal.

Gear whine in 1st and 2nd gears in a new rear wheel drive automatic transmission was identified as a potential customer dis-satisfier. Improvements to the vehicle system were implemented, but did not sufficiently reduce the noise. CAE modeling and hardware testing were used for gear tooth optimization, transmission system, driveline, and vehicle system studies. The planetary gears were re-designed with increased contact ratio, and significant interior noise reduction was achieved; but some vehicles still had excessive noise due to gear parameter variability from multiple sources. Using a DOE and statistical studies, a set of gear parameter targets were identified within the tolerances of the design, which achieved the program objectives for noise.

The penetration of rainwater through the heating ventilation and air conditioning system (HVAC) of a vehicle directly affects the provision of thermal comfort within the vehicle passenger compartment. Present vehicle designs restrict considerably the air-management processes due to reduced space and tighter packaging. The motivation for the study is to get an insight into factors affecting the water ingress phenomenon when a stationary vehicle is subjected to water loading such as heavy rain when parked or waiting in a traffic light or when in a car wash. The test programme made use of a compact closed circuit full-scale automotive climatic wind tunnel that is able to simulate wind, rain and road inclination. The tunnel was developed as part of the collaborative research between the Flow Diagnostics Laboratory (FDL) of the University of Nottingham and Visteon Climate Control Systems [1].

The evolution toward the use of electrostatic painting processes has been driven primarily by environmental legislation and efforts to improve efficiencies in the painting process. The development of conductive substrate material compliments the industry trend toward a green environment through further reductions in emissions of volatile organic compounds during the painting process. Traditionally, electrostatic painting of thermoplastics requires that a conductive primer be applied to the substrate prior to topcoat application. The conductive polymer blend of polyphenylene ether and polyamide provides sufficient conductivity to eliminate usage of conductive primers. Additional benefits include improved transfer efficiencies of the primer and top coat systems, uniform film builds across the part, and improved painting of complex geometries.

Automotive exterior paint systems can significantly affect the impact performance of thermoplastic body panels. To utilize the benefits of predictive engineering as a tool to assist in the design and development of thermoplastic body panels, thermoplastic body panel materials have been characterized with typical automotive paint systems for use for finite element modeling and analysis. Paint systems used for exterior body panels can vary from rigid to more flexible, depending on the vehicle manufacturer's specifications. Likewise, thermoplastics for body panels vary in mechanical properties, primarily depending on the heat performance requirements of the application. To understand the effects of paint systems on impact performance of thermoplastic body panels, two different paint systems, representing “rigid” and “more flexible,” were evaluated on two body panel grades of thermoplastics with different mechanical properties.

The drive to reduce weight, simplify assembly, and cut total system cost in today's vehicles is relentless. Replacing metal systems with thermoplastics has been of considerable interest in the engineering community. The current generations of engineering thermoplastic resins are enabling the use of plastic systems in demanding underhood applications. Technical data and discussion regarding the materials, design, molding, and assembly of lightweight composite throttle bodies will be presented in this paper. Comparisons with machined aluminum throttle housings are drawn to establish a baseline with the throttle body housing component that is most common in production today. Design flexibility and process simplification are some of the approaches highlighted. Much of the technical information provided in the paper applies to both cable driven mechanical throttle bodies as well as electronic throttle bodies under development.

For the past decade or so, automotive entertainment subsystem architectures have consisted of a simple Human Machine Interface (HMI), AM-FM tuner, a tape deck, an amplifier and a set of speakers. Over time, as customer demand for more entertainment features increased, automotive entertainment integrators made room for new features by allowing for the vertical integration of analog audio and adding a digital control. The new digital control came to entertainment subsystems via a low-speed multiplexing scheme embedded into the entertainment subsystem components, allowing remote control of these new features. New features were typically incorporated into the entertainment subsystem by independently packaging functional modules. Examples of these modules are cellular telephone, Compact Disc Jockey (CDJ), rear-seat entertainment, Satellite Digital Audio Radio System (S-DARS) receiver, voice and navigation with its associated display and hardware.

High-dilution stratified EGR combustion system operating at stoichiometric air-fuel ratio (A/F) could offer significant fuel economy saving comparable to the lean burn or stratified charge direct injection SI engines, while still complies with stringent emission standards by using the conventional three-way catalytic converter. The most critical challenge is to keep substantial separation between EGR gas and air-fuel mixture, or to minimize the mixing between these two zones to an acceptable level for stable and complete combustion. Swirl-type stratified EGR and air-fuel flow structure is considered desirable for this purpose, because the circular engine cylinder tends to preserve the swirl motion and the axial piston movement has minimal effect on the flow structure swirling about the same axis. In this study, KIVA3V was used to simulate mixing and combustion processes in a typical pent-roof gasoline engine cylinder during compression and expansion strokes.

The stand alone oil to air (OTA) transmission cooling strategy provides improved transmission cooling under high ambient air temperature operating conditions, which improves transmission reliability, durability and overall customer satisfaction. Another means of improving reliability and durability is through improved transmission warmup under low ambient air temperature operating conditions. To allow for improved transmission warmup, a thermostatic cold flow bypass valve has been incorporated into the transmission oil cooler. The bypass valve shuts off flow to the transmission oil cooler until a predetermined fluid temperature has been achieved. Once this temperature is reached, oil is allowed to flow to the transmission oil cooler. Visteon Climate Control Systems (VCCS) has tested both the stand alone OTA transmission cooling strategy with thermostatic cold flow bypass valve and the conventional transmission cooling strategy, comparing the transmission system warmup rates.

A closed loop full-scale automotive climatic wind tunnel is described. The tunnel simulates wind and rain as well as several road conditions. It generates under controlled heat loading, wind speeds of up to 50kmh with different approach boundary conditions, rains from drizzle to cloudburst and road inclines up to 15° in any direction. The design and optimization process of the tunnel functions is outlined and examples of its use in vehicle development are given. The size constraint and the need for a compact design are important features of the tunnel. The tunnel provides an important test bed for close scrutiny of the relationship between rain ingress, vehicle speed, road condition, heat loading and vehicle geometry. The tunnel can also be used to study vehicle thermal management, vehicle thermal comfort, engine cold starting, and wipers efficiency in sever cold weather.

An accelerated seat durability test was developed to identify potential problems in areas with traditionally high warranty cost and customer dissatisfaction: squeak & rattle and mechanism looseness & efforts. The test inputs include temperature, humidity, road vibration, occupant movements, and mechanism cycling. These inputs were combined into a single 14-day test profile that simulates 10 years and 250,000 km. (approximately 150,000 miles) of 95th percentile customer usage. Various components of the seat assembly are tested together as a system. The test was performed on two current production programs. The test produced issues similar to those found in warranty repair data and evaluations of used seats from high-mileage customer-owned vehicles.