Browse Topic: Racing engines

Items (135)
The world of Formula One (F1) is changing with impending 2026 F1 regulations imposing even stricter limits on engine component usage while increasing races. The valvetrain system, specifically the intake valves, is a critical determinant in controlling gas exchange within the cylinders, directly impacting air-fuel charge and power output. The aim of this investigation is to study the mechanisms of intake valve and valve seat wear which will influence engine performance due to leakage path development. The wear mechanism of the intake valves considers wear from impact from valve seat interaction, sliding and foreign particle abrasion for quantifying valve seat recession. An FIA 2026-2030 regulations compliant valve train model was developed in GT-Suite to help estimate valve seat wear. The validated model could predict valve recession for a given engine operating speed trace from racetrack data. This report presents a systematic methodology for developing valve seat wear quantification, the effects of charge leakage past the valve on engine performance and hence, performance degradation per race through the decrease of air-fuel charge. It was found that the average wear of the valve and valve seat is within an envelope of 39.6 μm to 48.1μm resulting in power losses of up to 1.6 kW per eight race stint. The proposed schemes can thus be used by power unit manufacturers to evaluate valve seat materials as well as valvetrain kinematics for improving reliability and life of valve train systems for a given race.
Soh, Sean KendrickSamuel, Stephen
The use of MAN-type loop scavenging port arrangements in a 125 cc two-stroke racing engine is being investigated. These make it possible to provide larger cross-sections for the transfer ports, but at the expense of the exhaust port cross-section. The investigation is carried out using 1D calculations with GT-Suite. It is shown that significantly higher maximum outputs are possible in this way. However, this requires large exhaust widths, as otherwise the exhaust port is too small and the advantage of the larger transfer cross-section is overcompensated. Mixed forms between the original MAN loop scavenging and Schnürle loop scavenging can represent a good compromise. To improve the power characteristic vs. speed, which is influenced negatively by the higher maximum outputs, optimizations of port heights and exhaust pipe dimensions are carried out. A configuration with the same maximum output as the basis but a wider power band is also shown. One open point is the quality of the scavenging. Results from the literature suggest that similarly good results are possible with MAN-type loop scavenging as with the Schnürle scavenging of the base engine. However, further investigations are required here.
Eilts, Peter
Hydrogen has emerged as a promising alternative fuel due to its potential to enable clean and sustainable energy systems. Direct injection is the preferred fueling strategy for hydrogen engines, as it enhances power density while addressing safety concerns. However, the low density of hydrogen necessitates a large molar quantity of fuel, leading to strong fuel-air stratification and posing challenges for mixing in a confined chamber with complex turbulent flow and jet/wall interactions. This challenge is exacerbated in the present study, where the evaluated high-performance engine operates at a high engine load (indicated mean effective pressure of about 20 bar) and an extremely high speed (7500 revolutions per minute). Furthermore, to target high efficiencies, restrict abnormal combustion behaviors and inhibit oxides of nitrogen emissions, a lean-burn combustion strategy with a global equivalence ratio of 0.4 was applied, where diffusive-thermal (DT) instability effects would matter. To elaborate on the complicated fundamentals dynamics from injection to combustion for this high-speed direct-injection spark-ignition hydrogen engine, this study intends to establish a well-validated computational framework based on measured engine combustion data. A flamelet-based combustion model, G-equation, was applied and analyzed. Specifically, the DT instability effects were considered for the generation of tabulated flame speeds and flame thicknesses. The main findings underscore the importance of incorporating DT effects to accurately capture combustion dynamics and further support the adjustment of boundary conditions and the turbulent Schmidt number to improve the modeling of hydrogen-air turbulent mixing.
Menaca, RafaelLiu, XinleiMortellaro, FabioMedda, MassimoIm, Hong G.
Internal combustion engines will play an important role in the coming decades, even considering targets of carbon neutrality for a sustainable future. This will be especially true in regions where pure electrified vehicle implementation is not yet practical, or for long-range heavy load transportation purposes, even in regions where BEV infrastructure is well established. HEV/PHEV’s importance and contribution to CO2 emission reduction together with carbon neutral fuels such as hydrogen, e-fuel and biomass fuel etc. will remain crucial regardless of region/transport sectors. In this respect, brake thermal efficiency improvements by friction reduction needs further investigation. This is especially so with the crankshaft bearings’ lubrication system, which can provide as much as 40% of the total mechanical losses in some cases. It is a well-established fact, that plain bearings require a minimum oil flow volume to maintain their real function rather than oil pressure. However, transportation of oil to the connecting-rod bearings, from the crank main journals, via a rotating oil supply hole inside the crankshaft, requires a certain minimum pressure in order to cope with centrifugal force. Additionally, the pressure drop caused by oil flow needs to be considered. An important aspect to lower the oil pressure requirement while maintaining requisite oil flow to the connecting-rod bearings, is the oil supply hole to crank rotating axis distance. This practice is already exploited in some racing engine crankshafts, which require higher rotation speeds than normal road use engines. Furthermore, minimizing oil leaks from bearings can enhance the bearing lubrication system’s efficiency. In order to overcome this dilemma and optimize the crankshaft bearing system, a distinct oil supply hole arrangement is adopted in the crankshaft. This crankshaft has oil supply holes far from the rotation axis and the crank pin oil outlet ports close to the crank axis. This crankshaft also has four inlet ports in the main journal, that additionally exploit dynamic pressure from crankshaft rotation. To explain this, the crankshaft is evaluated on an engine test bench and its friction reduction potential was quantified by analysing the test results.
Yajima, HiroshiMayumi, ShunichiMurakami, Motoichi
As the world strives toward the common goal of carbon neutrality by 2050, motorsport cannot be allowed to stand alone as an exception. A gradual energy transition is clearly underway in the automotive industry but has already begun in motorsport as well. Among other initiatives, the Dakar Rally and the FIA have created the T1 ultimate category for prototypes powered by low-carbon fuels, including hydrogen. The Dakar is the pinnacle of off-road endurance rally competitions. It offers a great opportunity to ORECA Magny-Cours and FEV to expose their jointly developed internal combustion engine (ICE), fuelled with hydrogen only, to extreme conditions. In addition, the racing environment imposes a unique pace of development which can serve as a catalyst for spurring the H2-ICE technology. Moreover, a hydrogen powered engine is an interesting fit for motorsports because it combines high power output, a relatively long driving range and driving pleasure with an excellent carbon footprint. This article outlines how ORECA Magny-Cours and FEV are currently converting a gasoline racing engine to hydrogen direct injection to meet the numerous challenges of the Dakar Rally. In several development steps, a combustion chamber was newly developed that is tailored to gaseous hydrogen combustion. A high level of charge motion and optimized mixture formation have ultimately been realized using FEV’s dedicated H2-ICE simulation tool chain. Design changes resulting from the simulation results are incorporated into the engine. Further thermodynamic investigations on an engine test bench will be undertaken by ORECA Magny-Cours to maximize performance while ensuring knock free operation and best engine efficiency. Although there are still development hurdles to overcome, the combined ORECA/FEV experience will bring a viable carbon neutral powertrain solution to compete in the future Dakar Rally.
Durand, ThomasAdomeit, PhilippBlomberg, MichaelJeihouni, YousefMichelet, FrancoisCombemale, LoicMeyer, Serge
How Honda's Grand Prix motorcycle program in the 1960s created the world's most-advanced IC engines. Fire-bombing destroyed Japan's 66 largest cities and their industry during World War II. After the war, more than 200 makers of light motorbikes sprang into being because such transportation could be quickly tooled for production. Only a few of the startups - those known for reliable, maintainable products - survived. By the late 1950s, saturation of the domestic market imposed a choice: export or stagnate. Only a few returning U.S. servicemen had ever heard of Honda motorcycles. Who would buy them? Soichiro Honda, a self-taught mechanic and former auto racer, knew that great names had been made through innovation and international racing success. On a 1950s tool-buying trip to Europe, he bought two racing machines - a German NSU and an Italian Mondial - for study in Japan. He committed his company to four-stroke engines and declared that it would compete in the Isle of Man TT road races that had shaped motorcycle development since 1907.
Cameron, Kevin
Published motorcycle lubricant research often focuses on developments to meet certain specifications, regulatory requirements, or a combination of the two. Seemingly missing from the literature is research where the primary goal is development of a lubricant that enables maximum torque, power and acceleration from a machine for the purpose of winning races. The present study combines the two areas of research, where a high-performance motorcycle engine oil platform is developed to be used in competition, while simultaneously meeting the necessary regulations and specifications to be useful for commuters and leisure riders alike. Well-known are the demands on a motorcycle oil, which must lubricate and protect the crankcase, clutch and gears, all of which have competing requirements such that a strategy to improve the performance in one area can cause a detriment in another. Formulating for racing engines that are typically much more powerful than production versions further exacerbates these dichotomies, where the traditional strategies for gaining power through the lubricant of reducing viscosity or adding friction-reducing chemistries can leave the clutch and gears open to severe damage. To meet these competing demands, a novel additive system with unique anti-wear and friction modifier chemistries was introduced to ensure clutch and gear protection while simultaneously improving power output and minimizing deleterious effects to aftertreatment devices. Further, the oils were designed to withstand the higher temperatures, speeds and power densities found in high performance machines through improved antioxidants, base stocks and shear-stable polymers, which also provide durability across the oil drain interval for leisure riders and commuters alike. Through a combination of performance bench testing, engine dynamometer testing and field testing on the track, it was demonstrated that substantial power gains can be achieved while still maintaining hardware protection, thus achieving the goal of a high-performance racing oil that is also suitable for everyday use.
Marcella, MikeJohnson, Aaron
Investigation of an Innovative Combustion Process for High-Performance Engines and Its Impact on Emissions2019-01-00391/15/2019
Over the past years, the question as to what may be the powertrain of the future has become ever more apparent. Aiming to improve upon a given technology, the internal combustion engine still offers a number of development paths in order to maintain its position in public and private mobility. In this study, an innovative combustion process is investigated with the goal to further approximate the ideal Otto cycle. Thus far, similar approaches such as Homogeneous Charge Compression Ignition (HCCI) shared the same objective yet were unable to be operated under high load conditions. Highly increased control efforts and excessive mechanical stress on the components are but a few examples of the drawbacks associated with HCCI. The approach employed in this work is the so-called Spark Assisted Compression Ignition (SACI) in combination with a pre-chamber spark plug, enabling short combustion durations even at high dilution levels. This operation mode leads to substantial improvements in terms of fuel consumption up to highest load conditions. Developed in close collaboration with Volkswagen Motorsport and the FKFS, the experimental investigations are carried out on a single cylinder test bench at the Technical University of Munich (TUM). The test bench is directly derived from the Volkswagen WRC 1.6l DI-SI race engine. In a numerical approach, the 3D-CFD engine development tool QuickSim is used to gain a detailed understanding of charge motion, mixture formation, and combustion. As a first step, we want to assess the effects of engine operating parameters such as engine load and engine speed on both boosted conventional and SACI operation. Secondly, we want to give an overview on the magnitude of the formulation of NOx and particle emissions in the presence of different ignition modes. The latter is aimed at addressing one of the many remaining questions in order to apply SACI operation to series production engines.
Koch, DanielBerger, ViniciusBittel, AlexanderGschwandtner, MaximilianWachtmeister, GeorgChiodi, MarcoKaechele, AndreasBargende, MichaelWichelhaus, Donatus
Model-Based Approach for Engine Performance Optimization2018-32-008210/30/2018
State-of-the-art motorcycle engines consist of numerous variable components and require a powerful motor management to meet the growing customer expectations and the legislative requirements (e.g. exhaust and noise emissions, fuel consumption) at the same time. These demands are often competing and raise the level of complexity in calibration. In the racing domain, the optimization requirements are usually higher and test efficiency is crucial. Whilst the number of variables to control is growing, the time to perform an engine optimization remains the same or is even shortened. Therefore, simulation is becoming an essential part of the engine calibration optimization. Considering the special circumstances in racing, involving valuable hardware, as well as extremely short development and calibration iteration loops, only transient testing is possible. By utilizing model-based testing and optimization, Ducati Corse, the racing team division of the well-known motorcycle manufacturer Ducati, improved the ability to optimize their race engines efficiently. By using an engine model it is possible to make extremely quick calibration adaptations. All parameters can easily be optimized with respect to potential constraints without running the engine on a testbed. Moreover, the re-use of the engine model for co-simulations is applicable and sharing it with other departments in the company is possible to increase efficiency even more. AVL CAMEO™ - the intelligent automated calibration environment - supports all engine optimization requirements with a consistent workflow from the task definition to the verification. For this specific racing use case, the software solution was implemented for the test planning using DoE (Design of Experiment), the data plausibility check and the empirical engine modeling. In addition, AVL CAMEO™ was the tool for realizing the model-based optimization and map creation. With the implementation of the model-based approach, the motorcycle manufacturer has successfully improved the engine performance optimization. An exact model of the engine is now available which supports a deep understanding of the engine behavior. Through realizing this calibration approach, quick office and race track adaptations are possible and alternative optimizations for different tracks or conditions are easy to execute.
Bartoccini, DavideNiedermaier, PeterGrassberger, Helmut Peter
As the importance of sustainability increases and dominates the powertrain development within the automotive sector, this issue has to be addressed in motorsports as well. The development of sustainable high-performance fuels defined for the use in motorsports offers technical and environmental potential with the possibility to increase the sustainability of motorsports at the same or even a better performance level. At the moment race cars are predominantly powered by fossil fuels. However due to the emerging shift regarding the focus of the regulations towards high efficient powertrains during the last years the further development of the used fuels gained in importance. Moreover during the last decades a huge variety of sustainable fuels emerged that offer a range of different characteristics and that are produced based on waste materials or carbon dioxide. This study investigates the question of which sustainable fuels offer the characteristics suitable for high-performance race engines. Equivalents to gasoline, diesel and natural gas are examined separately in order to present the options with various engine concepts. The requirements for a high-performance fuel are defined based on experimental investigations emphasizing among other characteristics the importance of the knock resistance for gasoline-like fuels and the ignitability for diesel-like fuels. Furthermore the characteristics of the sustainable alternatives are analyzed. On the basis of the experimental results a comparison is carried out to match the fuel requirements with the characteristics and to select the optimal equivalent for fossil gasoline, diesel and natural gas. Moreover the sustainable fuels are evaluated with an environmental analysis including the fuel life cycle. The results show a potential to reduce the greenhouse gas emissions per mega joule energy content by up to 88%. This research assesses the broad variety of sustainable biologic and synthetic fuels concerning the potential use in motorsports and the resulting environmental benefits.
Schwarz, LeaBargende, MichaelDreyer, StefanBaretzky, UlrichKotauschek, WolfgangWohlgemuth, SebastianBach, Florian
Minimizing the lap time for a given race track is the main target in racecar development. In order to achieve the highest possible performance of the vehicle configuration the mutual interaction at the level of assemblies and components requires a balance between the advantages and disadvantages for each design decision. Especially the major shift in the focus of racecar powerunit development to high efficiency powertrains is driving a development of lean boosted and rightsized engines. In terms of dynamic engine behavior the time delay from requested to provided torque could influence the lap time performance. Therefore, solely maximizing the full load behavior objective is insufficient to achieve minimal lap time. By means of continuous predictive virtual methods throughout the whole development process, the influence on lap time by dynamic power lags, e.g. caused by the boost system, can be recognized efficiently even in the early concept phase. As a first step, this paper presents a novel method that combines detailed 1D (one dimensional) gas dynamic engine models with the quasi steady state (QSS) lap time method. This allows for a predictive comprehension of lap time influence for different engine design parameters with the possibility to operate in an environment of detailed description of vehicle dynamics. Moreover, the direct application of 1D-CFD (computational fluid dynamics) engine models also increases the efficiency of the used virtual engineering tools. In a second step, this paper gives an insight into a model supported development process of a lean boosted 4-cylinder race engine. An evaluation of the model’s predictive capabilities and a sensitivity study of basic boost system parameters are also part of this publication.
Malcher, SimonBargende, MichaelGrill, MichaelBaretzky, UlrichDiel, HartmutWohlgemuth, Sebastian
In the continuous search for technology to improve the fuel economy and reduce greenhouse gas emission levels from the automotive vehicle, the automotive industry has been evaluating various technological options. Since the introduction of stringent legislative targets in Europe as well as in the United States of America in late 20th Century, one of the viable options identified by the industry was the application of alternative powertrain. On the motorsport arena, changes introduced by the Formula 1 governing body (FIA) for the high-performance racing engines also focuses on fuel economy. FIA regulation for 2014 restricts the fuel-flow rate to a maximum of 100kg/hr beyond 10,500 rev/min and prescribe fuel flow rate below 10,500 rev/min operating conditions for the F1 Engines. In addition, Formula1 and Le Mans racing regulations actively promote the integration of the hybrid powertrain in order to achieve optimum fuel economy. Therefore, the aim of the present work is to evaluate available technology choices and measure efficiency in terms of fuel consumption and CO2 emission level. This technology mining exercise has been carried out using a powertrain simulation tool based on a mid-size light duty vehicle. The benchmark powertrain architecture for a light-duty vehicle is based on legislative drive cycle. The technologies tested on the drive cycles are also to be tested in a racing prototype car (LMP1), around a lap at Le Mans Circuit. This report presents a systematic methodology for assessing technology choices for racing vehicle using powertrain simulation tool. It presents a merit matrix based on fuel economy, drive cycle energy analysis, to evaluate the powertrain ability to harvest the available energy on a given drive cycle.
Bengolea, FedericoSamuel, Stephen
Alongside with the severe restrictions according to technical regulations of the corresponding racing series (air and/or fuel mass flow), the optimization of the mixture formation in SI-race engines is one of the most demanding challenges with respect to engine performance. Bearing in mind its impact on the ignition behavior and the following combustion, the physical processes during mixture formation play a vital role not only in respect of the engine's efficiency, fuel consumption, and exhaust gas emissions but also on engine performance. Furthermore, abnormal combustion phenomena such as engine knock may be enhanced by insufficient mixture formation. This can presumably be explained by the strong influence of the spatial distribution of the air/fuel-ratio on the inflammability of the mixture as well as the local velocity of the turbulent flame front. With regard to the mixture formation processes and thus engine performance, both SI-engines with direct and port fuel injection show intrinsic advantages and drawbacks. The combination of the above systems may give rise to new possibilities in combining the particular benefits of both systems. Therefore, the potential of combined injection strategies, with reference to high performance and race engine applications, is presently investigated at the Institute of Internal Combustion Engines of the Technische Universität München by means of experimental approaches. Both a single cylinder research engine and optical spray diagnostics are used. Thus, the question of whether combined injection strategies can potentially enhance power output is examined. Furthermore, numerical 3d-CFD-simulations of gas exchange, mixture formation as well as combustion are carried out at the Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart with regard to the above injection strategies. The numerical data can then be validated by the experimental investigations from the single cylinder research engine.
Pötsch, ChristianBaumgartner, Laura SophieKoch, DanielBernhard, FelixBeyfuss, BastianWachtmeister, GeorgWichelhaus, Donatus
The paper discusses the benefits of a four stroke engine having one intake and one exhaust rotary valve. The rotary valve has a speed of rotation half the crankshaft and defines an open passage that may permit up to extremely sharp opening or closing and very large gas exchange areas. The dual rotary valve design is applied to a racing engine naturally aspirated V-four engine of 1000cc displacement, gasoline fuelled with central direct injection and spark ignition. The engine is then modeled by using a 1D engine & gas dynamics simulation software package to assess the potentials of the solution. The improved design produces much larger power densities than the version of the engines with traditional poppet valves revving at higher speeds, with reduced frictional losses, and with larger gas exchange areas while also improving the fuel conversion efficiency thanks to the sharpness of opening or closing events. The novelty in the proposed dual rotary valve system is the combustion chamber of good shape and high compression ratio with central direct injector and spark plug coupled to the large gas exchange areas of the rotary valve system. Finally, jet-ignition is shown as a valuable tool to improve the rate of combustion also in stoichiometric and near stoichiometric racing engines applications with benefits in terms of fuel conversion efficiency and combustion stability.
Boretti, AlbertoJiang, ShuhengScalzo, Joseph
Mazda's factory SkyActiv diesel race program switched to the Prototype class in 2014, teaching the SpeedSource team valuable engineering lessons for 2015. FORMULA SAE STUDENT ENGINEERS, TAKE HEED: You're not alone in seeking technical solutions, facing setbacks, and often tiptoeing through the minefield of successful racecar development. There are pros in the same situation. Just ask Sylvain Tremblay, whose SpeedSource race team recently completed its first season in the Prototype class of the new TUDOR United Sports Car Championship Grand Am Series. “As the only diesel car running in Prototype, using a production-based engine and a new fuel, we're exploring new territory one race at a time,” said Tremblay, a veteran engineer and skilled race driver whose Florida-based engineering company has built and campaigned Mazda's U.S. “works” cars since the rotary-engine era.
Brooke, Lindsay
Formula SAE racing engines must provide high output with maximum fuel efficiency despite the air restriction imposed by the rules. Throttle response and engine load control are very important due to the track characteristics with a few straights zones and many curves. In-cylinder pressure cyclic variations harm vehicle control and increase fuel consumption, due to the torque fluctuations. In order to reduce fuel consumption and improve vehicle drivability, engine calibration having the in-cylinder as a feedback parameter is an essential procedure and will be the focus of this paper. Test bench data with combustion analysis will be performed, using the COVIMEP as a combustion stability index. Tests were carried out on a motorcycle engine modified to run under the Formula SAE competition rules. A piezoelectric sensor was installed inside the combustion chamber to provide instantaneous pressure readings, which were used to on-line calculate the IMEP and perform a 200 cycle COVIMEP evaluation. The objective was to reduce the combustion variability at speeds and loads conditions which were defined as critical when analyzing track logged data from previous competitions. Air-fuel ratio and spark timing were varied and combined to reach a good compromise among COVIMEP, torque and fuel consumption. Values in the range of 2-5% on COVIMEP were achieved at part load operation conditions with an increase on torque and an expressive reduction on fuel consumption.
Tatsch, Gabriel AzevedoMartins, Mario Eduardo SantosLanzanova, ThompsonSari, Rafael LagoTaglieber, Victor HugoGörck, Cassio Lino
The paper reviews the experimental development of fuel economy of engine powering the 2012 Formula SAE single seat race car of the University of Sophia. The balance of high power and low fuel consumption is biggest challenge of racing engine. It was found that improving the efficiency of engine by supercharging as a way to achieve that. In order to adapt the supercharger for the engine, the important design points are below: It was found that intake air blow-by gas at combustion chamber is increased in low engine speed. To improve that, the valve overlap angle was changed to adopt supercharged engine and improve effective compression ratio. Typically the racing engine demands maximum torque for performance but that does not imply that the air fuel ratio should be rich than theoretical. The point is the maximum torque of the engine is proportional to the amount of air intake. Therefore, supercharged engine is possible to increase the supercharging pressure for bigger torque. But the base engine is not prepared for bigger torque, the damage of the engine was considered. In order to avoid engine breakage, the lean air-fuel ratio was used and maximum torque was controlled not to exceed an engine limit. The aim air fuel ratio was change by engine speed to get more flat torque performance, and improved the fuel consumption.
Fukuhara, YoshikiKimata, NaoyaSuzuki, Takashi
In the last years motorsport is facing a technical revolution concerning the engine technology in every category, from touring car championships up to the F1. The strategy of the car manufacturers to bring motorsport engine technology closer to mass production one (e.g. turbo-charging, downsizing and direct injection) allows both to reduce development costs and to create a better image and technology transfer by linking motorsport activities to the daily business. Under these requirements the so-called Global Race Engine (GRE) concept has been introduced, giving the possibility to use one unique engine platform concept as basis for different engine specifications and racing categories. In order to optimize the performance of this kind of engines, especially due to the highly complex mixture formation mechanisms related to the direct injection, it is nowadays mandatory to resort to reliable 3D-CFD simulations. In this paper the contribution of intensive CFD simulations within the engine development process will be shown, in particular some issues regarding the injection modeling and its influence on the prediction of the mixture formation, the combustion and the global engine performance will be analyzed.
Chiodi, MarcoPerrone, AntonellaRoberti, PaoloBargende, MichaelFerrari, AlessandroWichelhaus, Donatus
Computer software, which simulates the thermodynamic and gas dynamic of internal combustion engines, are used extensively during design and development process. This paper analyzes the 1D boundary multi-pipe junctions calculations using the Method of Characteristics (MOC). Sonic flows can be encountered in the exhaust manifolds of internal combustion engines (especially racing engines) and in the model a check if the flow is sonic or not have been made. Flows with more than one manifold have flow toward the junction, need an equivalent “Datum” manifold, with an airflow as the sum of all flows, an averaged area and stagnation enthalpy has been defined in order to calculate the pressure loss when crossing the junction. The pressure loss terms have been calculated as function of the flow-ratio of the gas flowing to the manifold to the total incoming flow and the pipe angle. Such terms take into account of the flow ratio referred to the “Datum” flow and the pipe angle term is the average of all the pressure losses of every duct with incoming flow. The main model used to calculate the wave actions in the manifolds is the Two Step Lax-Wenfroff scheme, second order in space and time with the TVD flux limiter, needed to smooth the instabilities typical of second order hyperbolic schemes. Two set of tests have been designed in order to show the advantages of the present formulation. The first is “Y” junction with an inlet duct. Increasing the inlet pressure, the flow increase up to reach the sonic flow. The second test is a Y junction with 2 inlet ducts with the third duct that goes to sonic flow. A racing engine has also been simulated comparing the results with those from a dynamometer, showing good accordance between model and measured data.
Ortenzi, FernandoVesco, Emiliana
Internal combustion engine components have been a main research interest over many decades [1]. While bulk material and surface engineering developments have improved the resistance to fatigue, reduced the amount of wear and friction during operation, small improvements in race applications designs can increase the engine performance and give a competitive edge to racing engines. Piston rings are designed to create a seal which means that they will suffer large levels of material loss due to wear during operation. The compression ring is the top or closest ring to combustion gases and is exposed to the highest operating temperature. In this paper, the authors propose a design modification to the compression ring coated chamfer which can reduce stress concentration and material loss during operation.
Dickinson, Matthew W.
Ethanol has received both positive and negative attention as a renewable fuel for spark ignition engines. Studies of ethanol have shown improved volumetric efficiency, knock tolerance, and favorable burn curves[1]. Nevertheless, little research has been published exploring the impact of ethanol blends on race engine performance coupled with the impact on well-to-wheels (WTW) greenhouse gases, emissions, and petroleum reduction. In this work, a circle track race vehicle powered by a GM Performance Parts 6.2L OHV CT-525 engine was tested using 100 octane race fuel and E85 over a matrix of configurations. Carburetion vs. fuel injection configurations were benchmarked with both fuels, with the addition of 100- and 300-cells-per-inch catalytic convertors. Testing involved both dynamometer testing and on-track testing utilizing a portable emissions measurement system. These data were used to determine the WTW greenhouse gas reduction, petroleum displacement, and criteria emission reduction, as well as the performance benefit, of E85 vs. race fuel over a matrix of technologies. Results show an increase in power for 87% of the drive cycle using E85 as compared to 100 octane race fuel. Using 85% cellulosic ethanol, WTW greenhouse gas reductions are on the order of 63%, and petroleum reductions are on the order of 81%. Additionally, performance increases are maintained using catalytic convertors and E85 relative to 100 octane race fuel and carburetion. For comparison, it is shown that utilizing an 85% blend of cellulosic ethanol, petroleum consumption and greenhouse gas impacts are similar in magnitude to those of a mid-sized, four-door sedan using standard fuel driving over mixed city/highway cycles.
Jehlik, ForrestBocci, Daniel
Design of Racing and High-Performance Engines 2004-2013PT-1572/12/2013
This compendium is an update to two best-selling editions published by SAE International in 1995 and 2003. Editor Doug Fehan has assembled a collection of technical papers from the SAE archive that will inspire readers to use race engine development as an important tool in the future of transportation. He focuses on several topics that are important to future race engine design: electrification, materials and processes, and improved technology. Today’s electric hybrid vehicles and kinetic energy recovery systems embody what inventors envisioned in the early 1900s. First employed in trams and trains of that era, the technology was almost forgotten until racers resurrected their version in 2009 F-1 racing. The automotive industry has long admired the aircraft industry’s use of lightweight metals, advanced finishing processes, and composites. The use of these materials and processes has helped reduce overall mass and, in turn, improved speed, performance, and reliability of race engines. Their initial high cost was a limiting factor for integrating them into mass-produced vehicles. With racing leading the way, those limitations were overcome and vehicles today feature some amazing adaptations of those processes and materials. Engine power, efficiency, durability, reliability, and, more recently, emissions have always been of primary importance to the automotive world. The expanding use of electrification, biofuels, CNG, high-pressure fuel delivery systems, combustion air management, turbocharging, supercharging, and low-viscosity lubricants have been the focus of race engine development and are now turning up in dealer showrooms. The papers in this publication were selected for two reasons: they demonstrate the leadership that racing plays in the future of automotive engineering and design as it relates to engines; and they will be interesting to everyone who may be in racing and to those who may want to be in racing.
Fehan, Douglas
Racing engines are required to be developed quickly in order to adapt to ever-changing regulations. A CFD-based optimization would be a useful tool to discover the best solution given the restrictions of the regulations. However, a CFD approach requires repeated trials and errors until the best solution is found because the numerical goal is unknown and the specifications required for the goal are never calculated back when using CFD. Therefore, this paper proposes an Empirically Integrated CFD Method. It is a combination of a one-dimensional CFD and several empirical equations that are derived from the racing engine database with physical meanings. These empirical equations give the CFD-based optimization a proper goal and primary specifications so as to make the optimization loop converge rapidly. This method is experimentally verified for its practical application with a prototype engine. Moreover, this prototype engine reveals the impact of the combustion chamber design on the thermal efficiency, which has not been reflected in conventional CFD. As a result of this study, the Empirically Integrated CFD Method for Racing Engine Layout is established.
Yasui, ShinsukeNakamura, Daisuke
Engine Design Concepts for World Championship Grand Prix MotorcyclesPT-1558/6/2012
The World Championship Grand Prix (WCGP) is the premier championship event of motorcycle road racing. The WCGP was established in 1949 by the sport's governing body, the Fédération Internationale de Motocyclisme (FIM), and is the oldest world championship event in the motorsports arena. This book, developed especially for racing enthusiasts by motorsports engineering expert Dr. Alberto Boretti, provides a broad view of WCGP motorcycle racing and vehicles, but is primarily focused on the design of four-stroke engines for the MotoGP class. The book opens with general background on MotoGP governing bodies and a history of the event’s classes since the competition began in 1949. It then presents some of the key engines that have been developed and used for the competition through the years. Technologies that are used in today’s MotoGP engines are discussed. A sidebar discussion on calculating brake, indicated, and friction performance parameters provides mathematical information for readers who like such technical details. Future developments of MotoGP engines, including the use of biofuels and recovery of thermal and braking energy, are presented. The introduction concludes with a chart that details the winners of the various classes of WCGP motorcycle racing since the competition began in 1949. The bulk of the book consists of four previously published SAE technical papers that were expressly chosen by Dr. Boretti to provide greater insight to the relationships between engine parameters and performance, namely the influence on friction and mean effective pressure of traditional spark ignited four stroke engines tuned for a narrow high power output. The first paper provides the reader with a quick way to estimate the friction loss and engine output. The second paper discusses output and fuel consumption of multi-valve motorcycle engines. The third paper, published in 2002, compares WCGP engines developed to comply with the then-new FIM regulations that allowed four-stroke engines in the competition. The fourth paper examines specific power densities and therefore the level of sophistication and costs of MotoGP 800 cm3 engines. This paper shows the performance of these as well as the 1000cc SuperBike engines. The fifth paper presents four engine concepts including one for a MotoGP/Superbike with 2 and 3 cylinders. The sixth paper compares 3 and 4 in-line, V4, V5, and V6 layouts through 1-D engine simulations. The seventh paper considers the actual operation of 800cc MotoGP engines on the race track, where the percentage of the duration in fully open throttle is less than 20% of the race, but the partial throttle is used for as much as 80% of the race. The final paper in the compendium reports on the Honda oval piston engine concept.
Boretti, Alberto
American upstart Motus readies a radical V4 sport-tourer, Ducati unleashes its most advanced V-twin, and electronic controls continue to migrate into the bike industry. “This has been a monumental undertaking,” noted Brian Case, Vice President of Design for Motus Motorcycles, a new U.S.-based start-up that is preparing to produce its first bike later this year as a 2013 model. Recent history doesn't exactly favor emergent U.S. motorcycle OEMs, but Case and Motus President Lee Conn believe their product will beat the odds. The Motus MST and MST-R are premium sport-touring machines more akin to European bikes than to cruisers in the Harley-Davidson mode. They're powered by an all-new 1650-cm3 V4 that is fundamentally half of a General Motors LS-7 V8-two overhead valves per cylinder actuated by pushrods, hydraulic lifters, and a single camshaft in the linerless aluminum block. The nickel-silicon-carbide coated bores are set on 4.27-in (108-mm) centers.
Brooke, Lindsay
In Motorsports the understanding of the real engine performance within a complete circuit lap is a crucial topic. On the basis of the telemetry data the engineers are able to monitor this performance and try to adapt the engine to the vehicle's and race track's characteristics and driver's needs. However, quite often the telemetry is the sole analysis instrument for the Engine-Vehicle-Driver (EVD) system and it has no prediction capability. The engine optimization for best lap-time or best fuel economy is therefore a topic which is not trivial to solve, without the aid of suitable, reliable and predictive engineering tools. A complete EVD model was therefore built in a GT-SUITE™ environment for a Motorsport racing car (STCC-VW-Scirocco) equipped with a Compressed Natural Gas (CNG) turbocharged S.I. engine and calibrated on the basis of telemetry and test bench data. The driver is simulated by means of a "position based" control in order to determine the braking points at each corner by itself and regulate the braking/accelerating intensity. By means of simplified vehicle dynamics and a complete engine flow dynamic modeling the behavior of the overall system during the lap can be analyzed and different scenarios simulated. In particular the focus is concentrated on the real operating conditions of the powertrain unit, which can be eventually combined also with energy recovery systems (e.g., KERS and TERS). In the proposed EVD model each technical element (Engine, Vehicle) is distinct and can be interchangeable. For example, the engine can be virtually optimized and the influence of different technical configurations or engine mapping on the global performance can be investigated. The aim is to create modeling solutions which are compatible with the short development time of motorsports and thus to maintain acceptable CPU-time. As results of the proposed simulations show, spark advance, fuel injection and direct control of the waste-gate (WG) are parameters which can influence the overall performance for the adopted racing vehicle.
Ferrari, AlessandroChiodi, MarcoBargende, MichaelRoberti, PaoloMillo, FedericoWichelhaus, Donatus
Readers' choice: Top technology stories of 2009AUTODEC09_0212/1/2009
The editors look back at the past year's most significant articles according to readers of Automotive Engineering International AEI Online, and Truck & Bus Engineering Online “Uneven- or irregular-interval firing has been employed in racing engines-the so-called ‘Big Bang,’ with more than one cylinder firing simultaneously,” said Masao Furusawa, Executive Officer of Yamaha Motor Co. and Senior General Manager of Engineering Operations, Motorcycle Headquarters, when telling the secret of Yamaha's winning formula in the MotoGP racing series. “Then there is the ‘Long Bang,’ with crank phases out of sync. Uneven-interval firing race engines have been known to improve lap times versus even-interval firing ones. How and why they work has not been clearly defined,” he said. Furusawa observed that, by simultaneous two-cylinder combustions, peak torque would double, producing a momentary burst of power, but conversely the total number of combustions decreases, thus obtaining the same total. “What the rider wants is combustion torque proportionate to the throttle work, not inertia torque,” said Furusawa, who drew an analogy to signal-to-noise ratio (SNR), an electrical engineering term. “Combustion torque is a signal, and inertia torque is noise. Unfortunately, noise increases proportionately to the square of revolutions, greatly deteriorating the SNR.” Verification of the Yamaha SNR theory was performed by directly measuring fluctuations in rear tire revolutions during cornering using frequency analysis. Furusawa concluded that the 90° crank engine transmitted the signal/combustion torque singularly and effectively to the driving wheel; this was proven when Racer Valentino Rossi won the MotoGP World Championship astride the Yamaha YZR-M1 in 2004 and 2005. The 2008 season was still young when Furusawa revealed his unique SNR theory and the smallest hint of the YZR-M1 technology. Full story at sae.org/mags/aei/5586
A Technique for Processing Cylinder Pressure and Test Bed Data Sets for Engine Speed-Sweep Tests to Allow Reduced Testing Time with Enhanced Interpretation of Results2008-01-300612/2/2008
The use of cylinder pressure data for high performance and racing engine development is widespread. However there are still opportunities to increase the efficacy of this measurement technology to accelerate engine power development and calibration. This paper covers techniques to efficiently derive more meaningful information from combustion test data using techniques learned from AVL Racing's engine development experience. The characteristics of good cylinder pressure data quality and system set-up (judicious filtering, proper pegging, encoder phasing, etc) will be reviewed, and the development of a novel technique for the efficient processing of the large amounts of test data that are generated will be presented. For sweep testing the integration of cylinder pressure and test bed data is hampered by the fact that test bed data is acquired at constant sampling rate, while cylinder pressure data is sampled at progressively higher frequency as engine speed increases. This makes the calculation of important engine performance metrics such as firing engine friction and net specific fuel consumption problematic for sweep tests. The analysis techniques presented in this paper allow the direct mathematical computation of cylinder pressure data with test bed data for engine speed sweep tests, resulting in the benefits of sweep testing (fast, minimum wear on engine, many different tests in a short time span) with the rigor of steady state step testing. The technique processes cylinder pressure and test bed separately at first, sorting all data into user defined speed bins and performing statistical evaluations on each bin. The analysis techniques also effectively smooth signals that are inherently noisy, such as CA50, IMEP, individual cylinder torque, and power. Variation in these metrics is captured with statistical metrics. Particular emphasis will be placed on the application of these data processing tools for accelerated engine hardware development using the unique insight afforded by these techniques.
Patterson, Gary J.
This protocol can be used for all forms of racing. Users can take the liberty to design a competition that uses all or specific parts of this document. As new information, fuels and technologies emerge, addendums or compete new protocols will be developed.
Green Racing Committee
Simulated Analysis of a Motorbike High Performance Lubrication Circuit2008-01-16476/23/2008
Race internal combustion engines are the result of several years of design made to satisfy the growing demand of high specific power. As a result of this increased specific power demand all of the engine components that require lubrication are exposed to a broader range of more extreme operating conditions. Hence an optimized design of a race engine lubricant circuit is becoming much more important, due to the necessity to have its effectiveness with a rational management of its own energy. In this paper, Authors analyse a motorbike high performance lubrication circuit by a simulation methodology, already used and validated for other high performance engine types. It will be illustrated a simulation model, made by mono-dimensional (1D) code, which allows to study all lubricant circuit behaviour, analyzing parameters that are not easy to evaluate experimentally and that, too often, designers don't take into account during engine development. These parameters allow the designer to study the whole lubricant circuit, highlighting eventual critical working conditions. The model was build up by a commercial code AMESim®, trade mark of LMS®. This code, by its own libraries, permits to the user to simulate the lubrication circuit and its components, taking into account all the problems concerning pressure drops, flow rate and heat exchange that characterize engine lubricant circuit behaviour. An useful instrument for lubricant circuit was been implemented to the aim of analyzing a complex architecture of an innovative 4 cylinder race motorbike high performance engine. This paper, then, represents an interesting step towards the growth of automotive engineering knowledge that is very important during the study and the development of a new engine.
Cardone, M.Senatore, A.Buono, D.Gustato, M.Scattolin, W.
MotoGP is the pinnacle of motorcycle racing, with the world's top riders racing 800cc prototype machines at leading venues around the world. The riders compete against each other to win the title and show their superiority. The manufacturers have improved the engines every year to gain high power with low-fuel consumption. The percentage of the duration in fully open throttle is less than 20% of the race, but the partial throttle is used as much as 80%. Moreover, when the rider accelerates the machine, the front tire is easy to be lifted from the ground. In the middle of corner, the rider cannot open the throttle fully because of the tire slip. Therefore, it is the most important factor to appropriately control a throttle in the partial area. The Drive-By-Wire (DBW) system is one of the solutions for the force control. The vehicle simulation in the engine dyno test helped efficiently to evaluate the DBW. As a result, a controllable engine was developed and the development costs were saved lower.
MATSUYAMA, KimihisaSUGI, MasamitsuYABE, Noboru
Exhaust port timing control devices or power valves were introduced into a two-stroke engine in response to the customer's desire for more power. This was the most cost-effective way for manufacturers to increase power over the entire rpm range without significantly modifying their original engine designs, thus ensuring that the excellent power-to-weight ratio characteristics intrinsic to the two-stroke engine were maintained. Varieties of different systems exist to control and operate these exhaust port modifiers. Some of the more sophisticated electronic systems incorporate auto-cleaning cycles at start-up, which help eliminate power valve sticking due to carbon build-up. The more economically designed systems, however, do not. As a result, the valves are more susceptible to deposits, which can reduce their functionality and significantly impact engine performance. Very heavy deposit formation can ultimately stick the valves and make them inoperable. New power valve additive technology has been developed to inhibit deposit formation on these exhaust port modifiers and to ensure consistent engine performance over many hours of operation. This development work was facilitated by utilizing two in-house engine tests. The first test stand, containing a Yamaha® YZ125H1™ motocross racing engine, was used as a gross screening tool to rank a large variety of different additive chemistries with respect to their power valve cleanliness performance. The best performing candidates were then further evaluated in a second engine test stand, containing a Polaris® 800 XC SP EDGE™ twin-cylinder snowmobile engine. This test procedure was specifically designed to serve as a finer discriminating tool for evaluating good performing lubricants and to further rank these oils based on their ability to minimize deposit formation. Various commercial lubricants were benchmarked using this engine test procedure, and the goal was to develop new additive technology that exceeded their current performance. Final proof of performance data was obtained by evaluating this new power valve additive technology in the field. In summary, for variable exhaust port modifiers to operate well, carbon build-up and gumming must be inhibited. The new power valve additive technology developed is significant and important because it successfully minimizes deposit formation and ensures improved and consistent engine performance.
Svarcas, Laimute R.Brenner, Michael S.
Unlike typical Japanese practice, the company revealed details on a handful of new compact cars and its supporting engine strategy. At what was supposed to be the Japanese launch of the Murano crossover SUV last year, President Carlos Ghosn of Nissan, soon to be CEO-elect of Renault, made the day an unusual one. Instead of introducing just that single model, Ghosn unveiled five more to be launched in quick succession within five months-an unprecedented onslaught in the Japanese domestic market where new model information is jealously guarded until the very last minute. Four of these new models are compact cars on the B and C platforms that are a product of the Franco-Japanese alliance. Nissan launched the March/Micra small car as the first vehicle on the jointly developed small car B platform. Renault is now launching its first vehicle on this platform, the Modus introduced at last year's Paris Motor Show. Three of Nissan's new models, the Tiida hatchback, Tiida Latio sedan, and Note/Tone small minivan are based on the stretched version of the B platform. Conversely, Renault preceded with the C platform-based Megane compact car series, with Nissan following with its own C platform-based minivan, the Lafesta.
Yamaguchi, Jack
The new A1 Grand Prix series, launched at the Autosport International show, borrows from other series to address motorsports' financial and safety concerns. Top-level motorsports in all types of categories all over the world are struggling with the very same issues: containment of escalating costs and speed. The problem is that going slower is anathema to racers and teams, even though going faster is bankrupting participants, and higher speeds endanger both competitors and spectators. Jaguar's withdrawal from Formula One (F1) and General Motors' retreat from the Indy Racing League are recent examples of how racing can be too expensive even for multinational corporations. The problem is that the whole paradigm of racing contributes to these issues.
Carney, Dan
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