Motorcycle Technology 

To meet increasing performance demand, motorcycle manufacturers require leading-edge vehicle technology, particularly in high-speed engine and high power-density designs. Southwest Research Institute (SwRI)  designs and develops vehicle powertrains that deliver the required performance while meeting strict emission and noise requirements. SwRI's Engine and Vehicle Research Division has achieved certification to ISO 9001, ensuring compliance with stringent quality control procedures in design, development, and research. SwRI has assembled a motorcycle development team to provide services ranging from concept design to durability testing. This dedicated team of motorcycle enthusiasts assists motorcycle and high-power engine manufacturers in their efforts to produce world-class vehicles. The Institute offers a wide variety of services, including:

• Powertrain component simulation
• Engine design and optimization
• Engine control development
• Hardware-in-the-loop evaluation
• Transmission and drivetrain development
• Frame and suspension evaluation
• Laboratory and dynamometer testing
• Emissions determination and reduction
• Environmental testing

Engine Design and Optimization

SwRI engineers design, develop, and optimize engine systems, assemblies, and components to improve performance, engine power output, fuel economy, exhaust emissions, and component costs. Using advanced design and analysis tools early in the design stage, engineers determine optimum engine parameters, including:

• Intake and exhaust system layout
• Piping length and diameter
• Plenum volume
• Cam profile
• Valve sizes
• Compression ratio
• Journal bearings

Using three-dimensional solid modeling, Institute engineers prepare a kinematic analysis of a proposed valve train assembly.

Institute engineers use advanced computational fluid dynamic techniques to model and simulate the action of numerous gases and liquids in engine-related components and systems, including:

• Combustion chamber
• Fuel injection system
• Fuel mixing
• Intake and exhaust ports
• Engine block and cylinder head cooling

SwRI conducts finite element analyses of all major engine assemblies and components such as:

• Cylinder heads
• Blocks
• Pistons
• Connecting rods
• Crankshafts
• Valve trains
• Fuel system components

Engineers use finite element analysis to improve crankshaft shape and optimize crank and throw of geometry, such as fillets and web shapes.

Institute engineers conduct static and dynamic analyses. Static analysis includes linear, nonlinear, plasticity, and multibody contact analyses. Dynamic analysis includes linear modal and nonlinear transient analysis with multibody contact.

Engine Control Development

Using sophisticated design and analysis techniques and state-of-the-art test facilities, SwRI engineers develop robust engine control systems that balance the often conflicting requirements of performance, fuel economy, and emissions. 

SwRI has developed a full-authority engine controller that provides:

• Real-time, model-based control
• Diagnostic functions
• Classic control
• Adaptive learn algorithms
• Advanced signal processing 

An SwRI-developed electronic controller uses advanced model-based algorithms to provide optimal engine and transmission performance.

Transmission and Drivetrain Development

Drivetrain development focuses on efficiently delivering engine power to the tire and road interface. SwRI optimizes the input/output ratios at the primary drive, transmission, and secondary drive while simultaneously maximizing the power density of each component. Institute engineers model, design, and analyze a wide array of power-transferring technologies, such as:

• Belts, including rubber and steel
• Chains
• Gears
• Automatic transmission

SwRI engineers maximize drivetrain efficiency through a variety of techniques, including:

• Reducing gear deflection
• Minimizing shaft bending
• Reducing windage and churning losses

To achieve maximum power density, engineers significantly reduce weight through:

• Material selection
• Surface improvements
• Dry-film lubricants
• Controlled material processes

Frame and Suspension Evaluation

Institute engineers model, simulate, and compare innovative suspension systems such as semi-active, damped in-arm systems and magnetostrictive and electrically controlled suspension systems. This information is evaluated against acceleration data, suspension displacements, and chassis strain. Engineers compensate for nonlinear responses in the suspension to provide improved road feel, response, and ride comfort. They also use this same information to perform high-speed, multi-axis fatigue testing of suspension and frame components.

Engineers optimize suspension components for dynamic response and improved handling.

Environmental and Laboratory Testing

Using state-of-the-art equipment and sophisticated laboratories, SwRI engineers and scientists provide a broad spectrum of environmental and performance tests, including:

• Emissions
• Braking
• Noise, vibration, and harshness (NVH) 
• Handling Fatigue
• Endurance and durability
• Electromagnetic compatibility

Because of the special requirements around the rider and the energy transmitted to the rider's body, SwRI emphasizes NVH issues, including:

• Intake- and exhaust-radiated noise
• Total airborne noise
• Shift quality
• Ride harshness

During controlled chassis dynamometer testing, Institute engineers evaluate engine performance and vehicle emissions.

Engine Performance Mapping and Development

SwRI develops and tests spark-ignition engines ranging from model airplanes to locomotives. SwRI engineers regularly conduct tests to evaluate engine performance, emissions, and fuel economy development. Using a wide range of sophisticated engine measurement techniques and development tools, engineers provide the following services:

• Camshaft development
• Intake system design and tuning
• Exhaust system optimization
• Electronic fuel system development and testing
• Cylinder head flow measurement and analysis
• Motoring friction analysis

SwRI staff monitor and inspect all pertinent operating parameters during the development process to ensure optimal engine operating efficiency, performance, and emissions.

During the engine development process, SwRI uses state-of-the-art diagnostic tools and techniques, including:

• Combustion system visualization
• Knock and misfire detection
• In-cylinder airflow and fuel-air mixing measurement
• Real-time oil consumption measurement
• Piston and ring motion measurement
• Computer cycle simulation

Vehicle Benchmarking

Institute engineers evaluate, analyze, and compare vehicles and electrical and mechanical systems to provide a scientific, nonbiased comparison of any vehicle. The Institute's testing, research, and development program includes a comprehensive range of research areas, including:

• Performance
• Emissions
• Fuel consumption
• Drivetrain efficiency
• Vehicle handling
• Fuel system components
• Engine component design

A wide variety of components, such as pistons, injectors, and crankshafts, are evaluated for reliability and their effects on fuel consumption, power output, and exhaust emissions.

Engine Durability Testing

Using industry standard or user-specified test cycles, SwRI routinely performs continuous, long-term engine testing to evaluate engine reliability and component durability. Open or closed-loop control of the engine and test conditions is provided with a variety of hardware and software platforms. Specially equipped test cells allow a wide spectrum of test capabilities, including altitude simulation, low-temperature environment (-35ºC), thermal cycling, and continuous engine monitoring.

Institute engineers provide rapid and cost-effective endurance testing and competitive engine evaluation.

Experienced engineers and technicians perform extensive standard and customized test procedures and practices. Engine health monitoring and inspections are integral to all engine tests. SwRI staff provide extensive services for monitoring engine operation, including:

• In-cylinder combustion pressure monitoring and analysis
• Combustion heat release analysis
• Coolant, oil, exhaust, and radiated heat rejection determination
• Engine teardown inspection
• Exhaust emission evaluation
• Failure analysis
• Fuel analysis
• Real-time component wear measurement
• Real-time oil consumption measurement
• Thermal imaging
• Blowby monitoring
• Air filter efficiency evaluation
• High-pressure leakdown determination

Using advanced environmental chamber testing, engineers monitor hot and cold engine and vehicle performance. Chassis and engine dynamometers in the cells aid in developing cold-start strategies, fuel injection calibration, and hot vehicle component evaluation.

This brochure was published in March 2001. For more information about motorcycle technology, visit the SwRI Motorcycle Technology web site or contact Suzanne Timmons, Phone (210) 522-2499, Fax (210) 522-3950 or Charles E. Roberts, Phone (210) 522-5521, Fax (210) 522-2019, Engine, Emissions and Vehicle Research Division, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas 78228-0510.

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