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In order to achieve predictable handling of a race car, local mounts connecting suspension components to the chassis should be sufficiently rigid to minimize unwanted local deflection which may adversely affect suspension geometry. In this work, the effects of local chassis flexibility of the spring perch on roll stiffness, tire camber change, and steer angle change are determined from a finite element model (FEM) of a Winston Cup race car. Details such as side gussets, supporting brackets, and local curvature of the frame rail spring pocket are included in a shell model of the spring perch. The local shell model of the spring perch is integrated with the global finite element stiffness model of the chassis and suspension consisting of an assembly of beam and shell elements. A parametric study on the effects of thickness changes for seven different areas of the spring perch has been performed.

The redistribution of weight due to lateral loading through a short-long arm suspension system requires non-linear methods to accurately predict the steady state deflections throughout the entire vehicle system. An iterative analysis approach which recalculates suspension deflections and movement in the location of center of gravity of the vehicle provides an improvement over linear analysis techniques. Such analysis provides a better understanding of short-long arm suspension systems leading to improved handling at high lateral loading and/or improved noise, vibration and harshness characteristics.

The forces required to control a car while cornering come from 4 small contact patches between the tire and road. Maximizing the average speed through the turn is almost entirely dependent upon the lateral force developed at these four points by the tires. Historically, these forces have not been measured directly, but secondary results such as lateral acceleration have been measured as an indicator of the total lateral force on the vehicle. In addition, tire characteristics have been measured from steady state measurements collected on a Force and Moment machine. Halliday Technologies Inc. has developed the Grip Evaluation and Management device, GEM, with which the lateral force developed by each tire mounted on a vehicle can be measured directly and recorded dynamically. The GEM device is patented in the USA and patents are pending in more than 20 other countries. This paper describes the operation of the GEM device, and presents some of the data collected to date.

In this paper, a comparison has been carried out between two Formula 1 engine architectures: a traditional V12 and a 12 cylinder with three banks and one crankshaft, which will be referred to from here on as W12. This comparison is made in terms of geometrical features, as well as in terms of safety coefficients, torsional stiffness, state of balance and friction losses. The W12's crankshaft is 158 mm shorter and stiffer than the V12's. Furthermore, this crankshaft is simpler and lighter. The W12 engine front section is wider. The crankshaft of the W12 has a minimum safety factor that is 30% lower than the V12's under the same operating conditions (18000 rpm, bmep=13 bar). While the V12 is perfectly self-balanced, the secondary forces are out of balance in the W12's crankshaft. This unbalance is, however, no more critical than the one occurring in a V10 or V8. Friction losses in the W12 should be slightly lower in comparison to the V12.

The SCCA (Sports Car Club of America) allows the use of synthetic rubber belt CVT transmissions in 3 classes: F-500, D-Sports and C-Sports. A rubber belt CVT system has been developed that can successfully transmit the 185 horsepower required to race competitively in the D-Sports class. This paper covers the development of the rubber belt CVT Transmission from a power level of 125 HP in 1986 to successfully racing with 185 HP in 1996. During the 10 year period the output level was increased by 50%. Advances in belt construction and component design to improve efficiency are described.

Formula One motorsport competition, ever seeking increases in powertrain responsiveness and efficiency, has utilized electronically-shifted manual transmissions for nearly a decade. With the advent of this technology for passenger car usage ( for example the Magneti Marelli “Selespeed” system), new levels of powertrain electronic control become possible. At the same time, world-wide emission and fuel economy standards have driven powertrain designers to seek transmissions that are multi-faceted; able to offer manual transmission levels of driveline efficiency while simultaneously offering the ability to be automatically controlled. This paper will document a 1995-1996 Chrysler advanced powertrain concept study that culminated in a fully driveable, fully automatic, manual 5 speed transmission Neon coupe.

The roll center is an important analysis tool for vehicle dynamics. But most analysis of the roll center is based on production cars, which usually have symmetric suspensions and a center of gravity near the centerline of the vehicle. Racing cars, particularly oval track stock cars, often have asymmetric suspensions and usually have a weight bias. For a car that is only going to turn left there is no reason for the left side front suspension to be anything like the right side. Oval track cars usually have as much weight on the inside as the rules allow. Analytical tools adapted from the standard industry texts or production car use do not properly address asymmetric suspensions. This paper will analyze the asymmetric suspension and discuss the role of the roll center. It will begin with a theoretical analysis of the roll center and the underlying assumptions.

This paper reports the results of a study to determine the benefits of utilizing high-speed digital cameras and motion analysis equipment for the purpose of data acquisition on racing vehicles. Having the ability to view the actual race vehicle in its transient or dynamic state, allows the race engineer to better relate and correlate with on-board data acquisition systems (DAS) and ultimately optimize the set-up of the racecar. Furthermore, the sophisticated motion analysis equipment used for this study allows the race engineer to pick points on the digital video and track their relative motions and displacements, thus providing an invaluable measurement tool for evaluating the tire, suspension components, or entire chassis, etc. This investigation examines the use of digital motion analysis for both drag racing vehicles and Indy cars.

Engineering in the Motorsports arena of ten involves the detailed comparison of two laps of data. Plots of data acquisition channels as a function of distance allow analysis of driver and vehicle performance at the same point on the track. Distance is computed from the Start/Finish line or wherever a timing beacon is placed. The distance function is usually defined as the integral of speed, which is calculated as the sum of discrete speed values. Speed is usually measured as the RPM of a wheel, usually a non-powered wheel, such as a front wheel for a rear-drive race car. The calculated distance function is subject to errors that can harm the analysis. For the four-mile Road America track this means counting the revolutions of a wheel from the timing beacon to a location up to 6,400 meters away. A skilled driver considers a variation of 3 meters a large change in braking point. This represents rolling a 27.5-inch diameter tire 2,900 times and defining a point within one revolution.

This paper explores the issues racing engineers face when crewchiefs and drivers do not have a precise understanding of their dynamic suspension systems or the facility to explain what is happening, real time, on the track; and presents original research on formal vs. “on the job training” among Winston Cup teams. The author suggests an approach whereby suspension engineers whose crewchiefs and drivers learn - whatever their formal engineering education -- to think in engineering terms and work in sympathy with what the car says, are better able to approach the limits of their racecars' performance.

Efforts to predict vehicle performance probably began shortly after Karl Benz drove his first three wheeler on the streets of Mannhiem, Germany in 1885. A century later, computers have accelerated and improved the precision of the predictive process. The challenge has been to achieve the highest level of predictive accuracy for the greatest variety of vehicle configurations operating in different environments, and to do it with the greatest ease and least burden for the person needing the answer. A computational method has been developed that meets those requirements and can be executed on a personal computer with as few as forty-seven inputs. At their discretion, users can input up to eighty-five specifications. The program is capable of generating its own values when certain specific information is not available. The performance predictive process follows the methodology published four decades ago by J. J.

Many in motorsports are involved in testing “one factor at a time” in order to learn best vehicle set-up. This strategy is a “trial and error” approach and has a very slow learning curve for developing and testing any racecar. Design of Experiments (DOE) is a methodology that can test multiple factors and their interactions. This methodology is a better “trial and learn” approach to better vehicle performance of any racecar. Learning is accelerated by an overall strategy of experimentation using DOE. Application of DOE is demonstrated with data from testing several factors at once for racecar setup in road racing and rallying.

This paper deals with the application of the optimal maneuver method to the assessment of motorcycle maneuverability. The optimal maneuver method is a novel approach to the analysis of vehicle performance. The essence of this method is the solution of an optimal control problem which consists in moving the vehicle, according to holding trajectory constraints, between two given endpoints in the “most efficient way”. The concept of “most efficient” is defined by a proper penalty function defined to express maneuverability. In this paper we briefly outline the method and give examples of its application to three classical maneuvers commonly used to test motorcycle handling: a slalom test, a lane change maneuver and a U-curve.

This paper describes the integration of a selection of techniques which can be used to design complex mechanical systems such as racing car suspensions. It covers aspects of their dynamic and static design with particular reference to system analysis, the theory of which is described within. Furthermore, the designs are evaluated using sophisticated data logging and kinematics and compliance rig tests to assess the manufactured design's performance. The optimisation of racetrack behaviour is then described using vehicle dynamics simulation to predict how performance improvements can be achieved quickly. The examples given relate to on going work on the University of Leeds Formula SAE Racing Car.

Fleet managers are always looking for ways to increase both maintenance shop safety and operational safety of their vehicles. This is especially true with heavy-duty equipment or equipment with high maintenance items in difficult to service locations. Incandescent lighting has always been one of the highest frequency of repair items on heavy-duty trucks and trailers. However, the technology now exists with light-emitting diodes (LEDs) to significantly increase the safety of operating and maintaining these vehicles.

“Outsource,” today's ‘buzz’ word, refers to a business practice that is not new to the North American trucking industry. This practice has had profound effects on the research and development of our truck drivetrains. In order to better understand the evolution of the medium and heavy duty truck drivetrain, a look at the history of the development of the Eaton Truck Axle will help to understand the high level of reliability and durability available in current heavy duty truck drivetrain components.

Rapid Prototyping, Fabrication and Tooling is a process that blends a series of technologies (machines, tools, and methods) capable of generating physical objects directly from a CAD database. The process dramatically reduces the time spent during product development by allowing for fast visualization, verification, iteration, optimization, and fabrication of parts and tools. Many new techniques of tooling have been and are being developed by using rapid fabricated parts. These are having a dramatic impact on both timing and costs throughout the automotive industry. One area that these methods can be utilized to their full potential is motorsports. Of particular interest is the growing use of bridge tooling to provide first article through production intent parts that promote cost effective changes.

Computers have made an impact in nearly every facet of professional racing. Most of the progress in the coming years will come as the tools that are in common use today, control systems, measurement tools, CAD, CAM, CFD, and the like, evolve and mature. This Paper argues that true innovation in the near future will come in the form of tools that help improve the two dominant facets that make a car faster - the ability of the driver and the intuition of the race engineer. The paper is divided into two parts, the first looks at the subject of information in racing1 and the second how this information infrastructure provides fertile ground for innovation with respect to driver and race engineer understanding.

Designing for optimal performance across a variety of situations involves compromise decisions. Through the investigation of a two-variable optimization of a vehicle for two different “races” the importance of this compromise design is underscored. The use of Pareto-minimal solution techniques, borrowed from game theory, aid in the design process by limiting the number of possible compromise designs, highlighting which solution applies for a given situation and providing some insight to the sensitivity of the design.

The design process followed for the design of a Formula-SAE engine is described. Current rules and past competition results were used to constrain the powertrain system. This system consists of the intake system, engine, transaxle, and exhaust system. Intake restrictor design is discussed. Options were compared using a friction analysis. Computer simulations were used to develop brake power and torque graphs. An analysis of thrust vs velocity graphs with those torque curves have been developed. This process serves as a useful tool in understanding the tradeoffs such as the number of cylinders, piston speed, cylinder size, etc; and how they can be used to develop a competitive package.