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Downhill tests are widely used as a method of evaluation, development and validation of braking efficiency, friction pair durability, braking balance, as well as fade characteristics and recovery of friction material properties. This test procedure is used for both: passenger vehicles and light & heavy commercial vehicles. The energy levels in the brake system are higher on commercial vehicles and the thermal characteristics much more critical. Added to the fact that such tests are conducted on public highways, it has an intrinsic security risk for both the vehicle tested and all others around. Until a few years ago, it was still feasible to conduct tests downhill on different routes keeping a high security level. Given an increasing traffic on highways, where the test is currently carried out, a need to create a similar downhill procedure (called Guaporé Mountain Test) within a Proving Ground under controlled conditions has been noticed.

During the development of a new friction material, besides the interface between lining/drum is also fundamental take in account all aspects involving the attachment of the linings on the brake shoes. This paper presents an optimization approach to the development and manufacturing parameters of brake linings, applied on medium and heavy duty commercial vehicles, aiming to assure the correct specification of the riveted joint clamp forces. These evaluations were conducted based on the quality tools documents and the theoretical aspects of the product usage as well as the modeling of key elements of the referred mechanism throughout various known applications. A calculation methodology was developed based on brake geometry, its generated forces and braking reactions required for each vehicle family.

This paper presents the experience of Ford Motor Company and Hitachi Metals Ltd., in the development and design of the exhaust manifolds for the new 1997 Ford 6.8L, Vl0 gasoline truck engine. Due to the high-exhaust temperature 1000 °C (1832 °F), heat-resisting nodular graphite irons, such as high-silicon molybdenum iron and austenitic iron with nickel cannot meet the durability requirements, mainly thermal fatigue evaluation. The joint effort by both companies include initial manifold design, prototype development, engine simulation bench testing, failure analysis, material selections (ferritic or austenitic cast steel), production processes (casting, machining) and final inspection. This experience can well be applied to the design and development of new cast stainless-steel exhaust manifolds in the future. This is valid due to the fact that US EPA is requiring all car manufacturers to meet the new Bag 6-Emission Standards which will result in increased exhaust gas temperature.

One of the major goals in the design of the new Ford Aeromax and Louisville heavy truck product line was to achieve competitive leadership in visibility. Market research found that visibility was an important issue to the heavy truck driver. Visibility is defined as both direct and indirect (i.e., the driver's ability to see with and without the use of supplemental vision devices such as mirrors) and both interior and exterior. The scope of this paper includes the work which was accomplished in evaluating direct and indirect exterior visibility and the resulting vehicle design which achieved Ford's leadership goals. Poor weather visibility and interior vision are beyond the scope of this paper. Polar Plots were the method of choice in the Aeromax/Louisville visibility studies. Industry acceptance of these techniques has been established in the recent approval of SAE J1750, “Evaluating the Truck Driver's Viewing Environment”.

Exhaust gas air-fuel ratio (A/F) sensors are common devices in powertrain feedback control systems aimed at minimizing emissions. Both resistive (using TiO2) and electrochemical (using ZrO2) mechanisms are used in the high temperature ceramic devices now being employed. In this work a new mechanism for making the measurement is presented based on the change in the workfunction of a Pt film in interaction with the exhaust gas. In particular it is found that the workfunction of Pt increases reversibly by approximately 0.7 V at that point (the stoichiometric ratio) where the exhaust changes from rich to lean conditions. This increase arises from the adsorption of O2 on the Pt surface. On returning to rich conditions, catalytic reaction of the adsorbed oxygen with reducing species returns the workfunction to its original value. Two methods, one capacitive and one thermionic, for electrically sensing this workfunction change and thus providing for a practical device are discussed.

Splash and spray conditions created by tractor-trailer combinations operating on the Federal highway system have been studied and tested for many years with mixed results. Past events are reviewed briefly in this paper. In additional testing during 1983, using new state-of- the-art splash/spray suppressant devices, some encouragement was provided that these devices could work. The 1984 Motor Vehicle Manufacturers Association (MVMA) test program was designed to develop practicable and reliable test procedures to measure effectiveness of splash and spray reduction methods applied to tractor-trailer combination vehicles. Over 40 different combinations of splash/spray suppression devices on five different tractors and three van trailer types were tested. The spray-cloud densities for some 400 test runs were measured by laser transmissometers and also recorded by still photography, motion pictures, and videotape. On-site observers made subjective ratings of spray density.

The use of a corrosion inhibited arsenical brass alloy for copper/brass radiator tubes has been identified as an effective means to protect the radiator tubes from external dezincification attack, which is generally caused by an exposure to excessive road salts in the regions such as Montreal and Toronto in Canada. Laboratory test methods, their results and field data verifying improved radiator life are presented.

The demand for improved fuel economy in both cars and trucks has emphasized the need for lighter weight components. The application of high strength steel to wheels, both rim and disc, represents a significant opportunity for the automotive industry. This paper discusses the Ranger HSLA wheel program that achieved a 9.7 lbs. per vehicle weight savings relative to a plain carbon steel wheel of the same design. It describes the Ranger wheel specifications, the material selection, the metallurgical considerations of applying HSLA to wheels, and HSLA arc and flash butt welding. The Ranger wheel design and the development of the manufacturing process is discussed, including design modifications to accommodate the lighter gage. The results demonstrate that wheels can be successfully manufactured from low sulfur 60XK HSLA steel in a conventional high volume process (stamped disc and rolled rim) to meet all wheel performance requirements and achieve a significant weight reduction.