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Rear-engine, Rear-wheel-drive Layout
In automotive design, an RR, or rear-engine, rear-wheel-drive layout places both the engine and drive wheels at the rear of the vehicle. In contrast to the RMR layout, the center of mass of the engine is between the rear axle and the rear bumper. Although very common in transit buses and coaches due to the elimination of the drive shaft with low-floor buses, this layout has become increasingly rare in passenger cars. Overview Most of the traits of the RR configuration are shared with the mid-engine rear-wheel-drive, or MR. Placing the engine near the driven rear wheels allows for a physically smaller, lighter, less complex, and more efficient drivetrain, since there is no need for a driveshaft, and the differential can be integrated with the transmission, commonly referred to as a transaxle. The front-engine front-wheel-drive layout also has this advantage. Since the engine is typically the heaviest component of the car, putting it near the rear axle usually results in ...
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Brake Bias
The brake balance or brake bias of a vehicle is the distribution of brake force at the front and rear tires, and may be given as the percentage distributed to the front brakes (e.g. 52%) or as the ratio of front and rear percentages (e.g. 52/48). The braking balance affects the driving characteristics in terms of how fast the vehicle can brake, how the vehicle can take corners, and tire wear. The optimal brake balance can vary between circuits, weather conditions and driving styles. On race cars, the brake balance is often part of the racing setup, and in formula car racing it is regularly adjusted during the course of an entire lap. In some cases, the brake balance may be adjusted to match the traction (grip) of the vehicle during braking, which usually means distributing a greater braking force to the front (for example 55/45). In other cases, it may be desirable for the brake balance to be the more similar at the front and rear (e.g. 50/50) for the tires to last longer, which m ...
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Porsche
Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see below), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany. The company is owned by Volkswagen AG, a controlling stake of which is owned by Porsche Automobil Holding SE. Porsche's current lineup includes the 718 Boxster/Cayman, 911 (992), Panamera, Macan, Cayenne and Taycan. History Origin Ferdinand Porsche (1875–1951) founded the company called "Dr. Ing. h. c. F. Porsche GmbH" with Adolf Rosenberger and Anton Piëch in 1931. The main offices was at Kronenstraße 24 in the centre of Stuttgart. Initially, the company offered motor vehicle development work and consulting, but did not build any cars under its own name. One of the first assignments the new company received was from the German government to design a car for the people; that is, a ''Volkswagen''. This resulted in the Volkswagen Beetle ...
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Water Cooling
Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and non-toxic; however, it can contain impurities and cause corrosion. Water cooling is commonly used for cooling automobile internal combustion engines and power stations. Water coolers utilising convective heat transfer are used inside high-end personal computers to lower the temperature of CPUs. Other uses include the cooling of lubricant oil in pumps; for cooling purposes in heat exchangers; for cooling buildings in HVAC and in chillers. Mechanism Advantages Water is inexpensive, non-toxic, and available over most of the earth's surface. Liquid cooling offers higher thermal conductivity than air cooling. Water has unusually high specific heat capacity among commonly available liquids at room temperature and atmospheric pressure allowi ...
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Porsche 930
The Porsche 930 is a sports car manufactured by German automobile manufacturer Porsche between 1975 and 1989, known to the public as the 911 Turbo. It was the maker's top-of-the-range 911 model for its entire production duration and, at the time of its introduction, was the fastest production car available in Germany. Model history Porsche began experimenting with turbocharging technology on their race cars during the late 1960s, and in 1972 began development on a turbocharged version of the 911. Porsche originally needed to produce the car in order to comply with homologation regulations and had intended on marketing it as a street legal race vehicle like the 1973 Carrera 2.7 RS. The FIA's Appendix "J” rules upon which the 911 Turbo Carrera RSR 2.1 was entered into competition in 1974 changed in 1975 and 1976. The FIA announced that cars for Group 4 and Group 5 had to be production cars and be available for sale to individual purchasers through manufacturer dealer networks. ...
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Volkswagen Beetle
The Volkswagen Beetle—officially the Volkswagen Type 1, informally in German (meaning "beetle"), in parts of the English-speaking world the Bug, and known by many other nicknames in other languages—is a two-door, rear-engine economy car, intended for five occupants (later, Beetles were restricted to four people in some countries), that was manufactured and marketed by German automaker Volkswagen (VW) from 1938 until 2003. The need for a ''people's car'' ( in German), its concept and its functional objectives were formulated by the leader of Nazi Germany, Adolf Hitler, who wanted a cheap, simple car to be mass-produced for his country's new road network (Reichsautobahn). Members of the National Socialist party, with an additional dues surcharge, were promised the first production, but the Spanish Civil War shifted most production resources to military vehicles to support the Nationalists under Francisco Franco. Lead engineer Ferdinand Porsche and his team took until 193 ...
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Air-cooled
Air-cooled engines rely on the circulation of air directly over heat dissipation fins or hot areas of the engine to cool them in order to keep the engine within operating temperatures. In all combustion engines, a great percentage of the heat generated (around 44%) escapes through the exhaust, not through the metal fins of an air-cooled engine (12%). About 8% of the heat energy is transferred to the oil, which although primarily meant for lubrication, also plays a role in heat dissipation via a cooler. ''Air-cooled engines'' are used generally in applications which would not suit liquid cooling, as such modern air-cooled engines are used in motorcycles, general aviation aircraft, lawn mowers, generators, outboard motors, pump sets, saw benches and auxiliary power units. Introduction Most modern internal combustion engines are cooled by a closed circuit carrying liquid coolant through channels in the engine block and cylinder head, where the coolant absorbs heat, to a he ...
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R4 Layout
In automotive design, an R4, or Rear-engine, Four-wheel-drive layout places the internal combustion engine at the rear of the vehicle, and drives all four roadwheels. This layout is typically chosen to improve the traction or the handling of existing vehicle designs using the rear-engine, rear-wheel-drive layout (RR). The R4 layout is very rare, only having been used on a small number of production vehicles. Notable vehicles with this layout include several high-performance Porsche sports cars, including the 959, the 911 Turbo since the introduction of the turbocharged version of the 993 series in 1995, and the 911 Carrera 4 introduced with the 964 series in 1989. Some Volkswagen Kübelwagen (the rear-engined beetle-based military vehicle used by Germany in World War II) variants were produced with 4-wheel or all-wheel drive, including the Type 86, Type 87, Type 98. Also, some Vanagons/Microbuses came in 4WD Syncro version. Examples File:Porsche 959 – Frontansicht ...
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M4 Layout
In automotive design, an M4, or Mid-engine, Four-wheel-drive layout places the internal combustion engine in the middle of the vehicle, between both axles and drives all four road wheels. It is a type of car powertrain layout. Although the term "mid-engine" can mean the engine is placed anywhere in the car such that the centre of gravity of the engine lies between the front and rear axles, it is usually used for sports cars and racing cars where the engine is behind the passenger compartment. The motive output is then sent down a shaft to a differential in the centre of the car, which in the case of an M4 layout, distributes power to both front and rear axles. The centre differential contained within many 4 wheel drive cars is similar to the conventional differential in a 2-wheel drive car. It allows torque to be distributed to both drive axles whilst allowing them to spin at different speeds, which vastly improves the cornering of a 4-wheel drive car on surfaces with high gri ...
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FR Layout
In automotive design, a FR, or front-engine, rear-wheel-drive layout is one where the engine is located at the front of the vehicle and driven wheels are located at the rear via a drive shaft. This was the traditional automobile layout for most of the 20th century. Modern designs commonly use the front-engine, front-wheel-drive layout (FF). It is also used in high-floor buses and school buses. Front mid-engine, rear-wheel-drive layout In automotive design, a front mid-engine, rear-wheel-drive layout (FMR) is one that places the engine in the front, with the rear wheels of vehicle being driven. In contrast to the front-engine, rear-wheel-drive layout (FR), the engine is pushed back far enough that its center of mass is to the rear of the front axle. This aids in weight distribution and reduces the moment of inertia, improving the vehicle's handling. The mechanical layout of an FMR is substantially the same as an FR car. Some models of the same vehicle can be classified ...
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Understeer
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occurs when a car steers less than the amount commanded by the driver. Automotive engineers define understeer and oversteer based on changes in steering angle associated with changes in lateral acceleration over a sequence of steady-state circular turning tests. Car and motorsport enthusiasts often use the terminology more generally in magazines and blogs to describe vehicle response to steering in a variety of maneuvers. Vehicle dynamics terminology Standard terminology used to describe understeer and oversteer are defined 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 Organizatio ...
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