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Wheelspin
A wheelspin occurs when the force delivered to the tire tread exceeds that of available tread-to-surface friction and one or more tires lose traction. This leads the wheels to "spin" and causes the driver to lose control over the tires that no longer have grip on the road surface. Wheelspin can also be done intentionally such as in drifting or doing a burnout. Applications Differentials Standard differentials (also referred to as "open" differentials) always apply equal torque to each wheel. In low traction situations, the total torque delivered to each wheel is limited to the torque that is required to make the wheel with the least traction slip. During a turn, the weight of the vehicle shifts away from the inner radius and to the outer radius, therefore the inner drive-wheel will often lose traction on hard cornering, and especially when accelerating through a curve. Locking differentials and limited slip differentials modify the manner in which torque is distributed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burnout (vehicle)
A burnout (also known as a peel out, power brake, or brakestand) is the practice of keeping a vehicle stationary and spinning its wheels, the resultant friction causing the tires to heat up and smoke. While the burnout gained widespread popularity in California, it was first created by Buddy Houston, his brother Melson and David Tatum II at Ted Edwards Drag Strip in Fairburn, Georgia, Fairburn Georgia (U.S. state), GA (later to become Houston Bros Drag Strip and Reds Drag Strip) in the mid-1960s. History The origins of burnouts can be traced to drag racing, where they have a practical purpose: drag racing racing slick, slicks perform better at higher temperatures, and a burnout is the quickest way to raise tire temperature immediately prior to a race. They also clean the tire of any debris and lay down a layer of rubber by the starting line for better Traction (mechanics), traction. The origin of the burnout can be traced to Ted Edwards Drag Strip in Fairburn GA in the mid-19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traction (engineering)
Traction, traction force or tractive force is a force used to generate Motion (physics), motion between a body and a tangential surface, through the use of either dry friction or shear force. It has important applications in vehicles, as in ''tractive effort''. ''Traction'' can also refer to the ''maximum'' tractive force between a body and a surface, as limited by available friction; when this is the case, traction is often expressed as the ratio of the maximum tractive force to the normal force and is termed the ''coefficient of traction'' (similar to coefficient of friction). It is the force which makes an object move over the surface by overcoming all the resisting forces like friction, normal loads (load acting on the tiers in negative ''Z'' axis), air resistance, rolling resistance, etc. Definitions Traction can be defined as: In vehicle dynamics, tractive force is closely related to the terms tractive effort and drawbar pull, though all three terms have different definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drifting (motorsport)
Drifting is a driving technique where the driver purposely Understeer and oversteer, oversteers, with loss of traction, while maintaining control and driving the car through the entirety of a corner or a turn. The technique causes the rear slip angle to exceed the front slip angle to such an extent that often the front wheels are pointing in the opposite direction to the turn (e.g. car is turning left, wheels are pointed right or vice versa, also known as opposite lock or Countersteering#Other uses, counter-steering). Drifting is traditionally performed using three methods: clutch kicking (where the clutch is rapidly disengaged and re-engaged with the intention of upsetting the grip of the rear wheels), weight transfer (using techniques such as the Scandinavian flick), and employing a handbrake turn. This sense of ''drift'' is not to be confused with the ''four wheel drift'', a classic cornering technique established in Grand Prix motor racing, Grand Prix and sports car racing. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential (mechanical Device)
A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others. A common use of differentials is in motor vehicles, to allow the wheels at each end of a drive axle to rotate at different speeds while cornering. Other uses include clocks and analogue computers. Differentials can also provide a gear ratio between the input and output shafts (called the "axle ratio" or "diff ratio"). For example, many differentials in motor vehicles provide a gearing reduction by having fewer teeth on the pinion than the ring gear. History Milestones in the design or use of differentials include: * 100 BCE–70 BCE: The Antikythera mechanism has been dated to this period. It was discovered in 1902 on a shipwreck by sponge divers, and modern research suggests that it used a differential gear to determine the angle between the ecliptic positions of the Sun and Moon, and thus the phase of the Moon. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locking Differentials
A locking differential is a mechanical component, commonly used in vehicles, designed to overcome the chief limitation of a standard open differential by essentially "locking" both wheels on an axle together as if on a common shaft. This forces both wheels to turn in unison, regardless of the traction (or lack thereof) available to either wheel individually. When the differential is unlocked (open differential), it allows each wheel to rotate at different speeds (such as when negotiating a turn), thus avoiding tire scuffing. An open (or unlocked) differential always provides the same torque (rotational force) to each of the two wheels on that axle. Therefore, although the wheels can rotate at different speeds, they apply the same rotational force, even if one is entirely stationary, and the other spinning (equal torque; unequal rotational speed). By contrast, a locked differential forces both left and right wheels on the same axle to rotate at the same speed under nearly all ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limited Slip Differential
A limited-slip differential (LSD) is a type of differential gear train that allows its two output shafts to rotate at different speeds but limits the maximum difference between the two shafts. Limited-slip differentials are often known by the generic trademark Positraction, a brand name owned by General Motors and originally used for its Chevrolet branded vehicles. In an automobile, such limited-slip differentials are sometimes used in place of a standard differential, where they convey certain dynamic advantages, at the expense of greater complexity. Early history In 1932, Ferdinand Porsche designed a Grand Prix racing car for the Auto Union company. The high power of the design caused one of the rear wheels to experience excessive wheel spin at any speed up to . In 1935, Porsche commissioned the engineering firm ZF to design a limited-slip differential to improve performance. The ZF "sliding pins and cams" became available, and one example was the Type B-70 used during t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Understeer And Oversteer
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of the vehicle to changes in steering angle associated with changes in lateral acceleration. This sensitivity is defined for a level road for a given steady state operating condition by the Society of Automotive Engineers (SAE) in document J670SAE International Surface Vehicle Recommended Practice, "Vehicle Dynamics Terminology", SAE Standard J670, Rev. 2008-01-24 and by the International Organization for Standardization The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. M ... (ISO) in document 8855.International Organization for Standardization, "Road vehicles – Vehicle dynamics and road-holding ability – Vocabulary", ISO Standard 8855, Rev. 2010 Whether the vehicle is understeer or overste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rear-wheel Drive
Rear-wheel drive (RWD) is a form of engine and transmission layout used in motor vehicles, in which the engine drives the rear wheels only. Until the late 20th century, rear-wheel drive was the most common configuration for cars. Most rear-wheel drive vehicles feature a longitudinally-mounted engine at the front of the car. Layout The most common layout for a rear-wheel drive car is with the engine and transmission at the front of the car, mounted longitudinally. Other layouts of rear-wheel drive cars include front-mid engine, rear-mid engine, and rear-engine. Some manufacturers, such as Alfa Romeo, Lancia, Porsche (944, 924, 928) and Chevrolet (C5, C6, and C7 Corvettes), place the engine at the front of the car and the transmission at the rear of the car, in order to provide a more balanced weight distribution. This configuration is often referred to as a transaxle since the transmission and axle are one unit. History 1890s to 1960s Many of the cars built in the 19th cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
All-wheel Drive
An all-wheel drive vehicle (AWD vehicle) is one with a powertrain capable of providing power to all its wheels, whether full-time or on-demand. Types The most common forms of all-wheel drive are: ;1x1 : All unicycles Reflects one axle with one wheel capable of being powered. ; 2x2 : Some motorcycles and bikes Reflects two axles with one wheel on each capable of being powered. ; 4×4 (also, four-wheel drive or 4WD): Reflects two axles with both wheels on each capable of being powered. ; 6×6 (also, six-wheel drive or 6WD): Reflects three axles with both wheels on each capable of being powered. ; 8×8 (also, eight-wheel drive or 8WD): Reflects four axles with both wheels on each capable of being powered. Vehicles may be either part-time all-wheel drive or full-time: ;On-demand or Part-time: One axle is permanently connected to the drive, the other is connected as needed ;Full-time or Permanent: All axles are permanently connected, with or without a differential. ;Independ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Front-wheel Drive
Front-wheel drive (FWD) is a form of internal combustion engine, engine and transmission (mechanics), transmission layout used in motor vehicles, in which the engine drives the front wheels only. Most modern front-wheel-drive vehicles feature a transverse engine, rather than the conventional longitudinal engine arrangement generally found in automobile layout#Rear wheel drive layouts, rear-wheel-drive and four-wheel drive, four-wheel-drive vehicles. Location of engine and transmission By far the most common layout for a front-wheel-drive car is with the engine and transmission at the front of the car, mounted transversely. Other layouts of front-wheel drive that have been occasionally produced are a front-engine mounted longitudinally, a mid-engine layout and a rear-engine layout. History Prior to 1900 Experiments with front-wheel-drive cars date to the early days of the automobile. The world's first self-propelled vehicle, Nicolas-Joseph Cugnot's 1769/1770 Nicola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift-off Oversteer
Lift-off oversteer (also known as trailing-throttle oversteer, throttle off oversteer, or lift-throttle oversteer) is a form of sudden oversteer. While cornering, a driver who closes the throttle (by lifting a foot off the accelerator, hence the name), usually at a high speed, can cause such sudden deceleration that the vertical load on the tires shifts from rear to front, in a process called load transfer. This decrease in vertical load on the rear tires in turn decreases their traction by lowering their lateral force (that perpendicular to the direction of travel), making the vehicle steer more tightly into the turn. In other words, easing off the accelerator in a fast turn can cause a car's rear tires to loosen their grip so much that the driver loses control and drifts outwards, even leaving the road tailfirst. Such uncontrolled drifting should not be confused with the sport of intentionally drifting a motor vehicle. Dynamics The graphs to the right show the simulated eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
