31-482: The Audi RS 2 Avant is a high-performance version of the Audi 80 Avant estate car , manufactured from March 1994 to July 1995. Collaboratively designed as a joint venture between Audi AG and Porsche and based on Audi's B4/8C platform, it received the internal designation of P1 . It featured the most powerful version of Audi's inline-five cylinder turbocharged engine. It represents Audi's first " RS " model, and
62-414: A Coupé , as well as saloon model with only 306 examples built. It featured a similar turbocharged 2,226 cm (135.8 cu in) five-cylinder engine which delivered 162 kW (220 PS; 217 bhp) (3B engine), or 169 kW (230 PS; 227 bhp) (ABY engine). High-performance vehicle A performance car is a car that exhibits above-average capabilities in one or more of
93-586: A motive power output of 315 PS (311 bhp; 232 kW) at 6500 rpm and 410 N⋅m (302 lb⋅ft) at 3000 rpm of torque . Although much of the car's underpinnings were manufactured by Audi, assembly was handled by Porsche at their Rossle-Bau plant in Zuffenhausen , Germany , which had become available after discontinuation of the Mercedes-Benz 500E , which Porsche had manufactured there under contract. The Rossle-Bau plant also produced
124-401: A common shaft. This forces both wheels to turn in unison, regardless of the traction (or lack thereof) available to either wheel individually. When this function is not required, the differential can be "unlocked" to function as a regular open differential. Locking differentials are mostly used on off-road vehicles, to overcome low-grip and variable grip surfaces. An undesirable side-effect of
155-426: A gearing reduction by having fewer teeth on the pinion than the ring gear . Milestones in the design or use of differentials include: During cornering, the outer wheels of a vehicle must travel further than the inner wheels (since they are on a larger radius). This is easily accommodated when the wheels are not connected , however it becomes more difficult for the drive wheels , since both wheels are connected to
186-455: A low-pressure exhaust system replaced the standard fare; a specially modified URS4/URS6 Bosch -supplied engine control unit (ECU) controlled the engine. The RS 2 could accelerate from 0 to 100 km/h (62 mph) in 4.8 seconds, and achieve a maximum speed of 262 km/h (163 mph) (electronically restricted), despite weighing over 1,600 kg (3,500 lb). In a road test conducted in 1995, British car magazine Autocar timed
217-412: A pointer which constantly pointed to the south, no matter how the chariot turned as it travelled. It could therefore be used as a type of compass . It is widely thought that a differential mechanism responded to any difference between the speeds of rotation of the two wheels of the chariot, and turned the pointer appropriately. However, the mechanism was not precise enough, and, after a few miles of travel,
248-494: A regular ("open") differential is that it can send most of the power to the wheel with the lesser traction (grip). In situation when one wheel has reduced grip (e.g. due to cornering forces or a low-grip surface under one wheel), an open differential can cause wheelspin in the tyre with less grip, while the tyre with more grip receives very little power to propel the vehicle forward. In order to avoid this situation, various designs of limited-slip differentials are used to limit
279-454: A type of mechanical analogue computer, were used from approximately 1900 to 1950. These devices used differential gear trains to perform addition and subtraction. The Mars rovers Spirit and Opportunity (both launched in 2004) used differential gears in their rocker-bogie suspensions to keep the rover body balanced as the wheels on the left and right move up and down over uneven terrain. The Curiosity and Perseverance rovers used
310-521: The braking system wore Porsche-badged Brembo calipers, and both the wheels and side mirrors were identical in design to those of the 964 Turbo . Additionally, the word "PORSCHE" is inscribed in the RS 2 emblem affixed to the rear tailgate and front grille . A three-spoke leather steering wheel , Recaro sports-bucket seats (available in full leather or a leather/ suede combination), and console materials in either wood or carbon fiber trim rounded out
341-449: The "correct" time, so an ordinary clock would frequently have to be readjusted, even if it worked perfectly, because of seasonal variations in the equation of time. Williamson's and other equation clocks showed sundial time without needing readjustment. Nowadays, we consider clocks to be "correct" and sundials usually incorrect, so many sundials carry instructions about how to use their readings to obtain clock time. Differential analysers ,
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#1732779698405372-525: The 'modified' option included identical sized discs, but merely included cross-drilling, along with uprated pads. The hand brake worked on the rears, and consisted of a cable operated 'drum in disc' system. 40 millimetres (1.6 in) lower than a standard 80 Avant, the suspension and braking upgrades combined to give the RS 2 the handling and braking capabilities of a high-end sports car ; 7.0Jx17 inch Porsche 'Cup' wheels, and high-performance 245/40 ZR17 Dunlop tyres were standard as well. In fact,
403-479: The RS 2 from 0 to 30 mph (48 km/h) at just 1.5 seconds, which they confirmed was faster than the McLaren F1 road car. It could accelerate on-par with the 5th generation Chevrolet Corvette (C5) and a 996 generation Porsche 911 . A six-speed manual gearbox (parts code prefix: 01E, identification code: CRB) ( gear ratios - 1st: 3.500, 2nd: 1.889, 3rd: 1.320, 4th: 1.034, 5th: 0.857, 6th: 0.711)
434-621: The Sun and Moon position pointers. The ball was painted black and white in hemispheres, and graphically showed the phase of the Moon at a particular point in time. An equation clock that used a differential for addition was made in 1720. In the 20th century, large assemblies of many differentials were used as analogue computers , calculating, for example, the direction in which a gun should be aimed. Chinese south-pointing chariots may also have been very early applications of differentials. The chariot had
465-551: The carrier is rotated (by the input torque), the relationship between the speeds of the input (i.e. the carrier) and that of the output shafts is the same as other types of open differentials. Uses of spur-gear differentials include the Oldsmobile Toronado American front-wheel drive car. Locking differentials have the ability to overcome the chief limitation of a standard open differential by essentially "locking" both wheels on an axle together as if on
496-408: The dial could be pointing in the wrong direction. The earliest verified use of a differential was in a clock made by Joseph Williamson in 1720. It employed a differential to add the equation of time to local mean time , as determined by the clock mechanism, to produce solar time , which would have been the same as the reading of a sundial . During the 18th century, sundials were considered to show
527-480: The difference in power sent to each of the wheels. Torque vectoring is a technology employed in automobile differentials that has the ability to vary the torque to each half-shaft with an electronic system; or in rail vehicles which achieve the same using individually motored wheels. In the case of automobiles, it is used to augment the stability or cornering ability of the vehicle. Non-automotive uses of differentials include performing analogue arithmetic . Two of
558-480: The differential's three shafts are made to rotate through angles that represent (are proportional to) two numbers, and the angle of the third shaft's rotation represents the sum or difference of the two input numbers. The earliest known use of a differential gear is in the Antikythera mechanism, c. 80 BCE, which used a differential gear to control a small sphere representing the Moon from the difference between
589-667: The early 1990s. RS 2s have now been imported to Canada and USA as both allow non-conforming vehicles to be imported once they reach the age of 15 and 25 years respectively. The RS 2 was the product of a co-development project between Audi and Porsche , based on Audi's 80 Avant, and built on the Audi B4 platform . It was powered by a modified version of their 2,226 cc (2.2 L; 135.8 cu in) inline-five DOHC four valves per cylinder (20 valves total) turbocharged petrol engine (parts code prefix: 034, identification code: ADU). This internal combustion engine produced
620-405: The engine (usually via a transmission). Some vehicles (for example go-karts and trams ) use axles without a differential, thus relying on wheel slip when cornering. However, for improved cornering abilities, many vehicles use a differential, which allows the two wheels to rotate at different speeds. The purpose of a differential is to transfer the engine's power to the wheels while still allowing
651-399: The famous Porsche 959 . Like the rest of the vehicle, the RS 2's five-cylinder engine was based on a unit that Audi already produced, although Porsche considerably modified the engine; the standard KK&K turbocharger was switched for a larger unit, along with a heavy-duty intercooler and higher flow fuel injectors , a newly designed camshaft , a more efficient induction system, and
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#1732779698405682-470: The first of their high-performance Avants. It is a limited-edition model that was not widely exported outside of Europe, except in limited quantity to Hong Kong , South Africa, Brazil, and New Zealand . However, the RS 2 has amassed a cult following worldwide including Canada and the United States where the RS 2 was not officially imported due to certification costs and weak brand performance in
713-430: The following areas: acceleration ( torque and throttle response ), top speed ( horsepower ), cornering and braking . It is debated how much performance is required to move classification from standard to high performance. Further classification of performance cars is possible in the following categories: Differential (mechanical device) A differential is a gear train with three drive shafts that has
744-401: The front axle and the rear axle in an all-wheel drive vehicle. An advantage of the epicyclic design is that it is relatively compact width (when viewed along the axis of its input shaft). A spur-gear differential has an equal-sized spur gears at each end, each of which is connected to an output shaft. The input torque (i.e. from the engine or transmission) is applied to the differential via
775-481: 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
806-410: The propshaft to the half-shafts) and provide a reduction in the gear ratio . The components of the ring-and-pinion differential shown in the schematic diagram on the right are: 1. Output shafts ( axles ) 2. Drive gear 3. Output gears 4. Planetary gears 5. Carrier 6. Input gear 7. Input shaft ( driveshaft ) An epicyclic differential uses epicyclic gearing to send certain proportions of torque to
837-418: The rotating carrier. Pinion pairs are located within the carrier and rotate freely on pins supported by the carrier. The pinion pairs only mesh for the part of their length between the two spur gears, and rotate in opposite directions. The remaining length of a given pinion meshes with the nearer spur gear on its axle. Each pinion connects the associated spur gear to the other spur gear (via the other pinion). As
868-675: The standard Audi 80 equipment, however, the Bosch Anti-lock braking system (ABS) was retained. The front brakes feature either 304 millimetres (11.97 in) in diameter by 32 mm (1.260 in) thick radially ventilated disc brakes , and use Brembo four-opposed piston fixed calipers , or a 'modified' option of larger discs (which will only fit under a 17" wheel) of 322 mm (12.68 in) by 32 mm (1.260 in), with uprated brake pads. The rears featured 299 mm (11.77 in) by 24 mm (0.945 in) radially vented discs, again with Brembo four-piston calipers, and
899-458: The vehicle's interior changes. Audi's proprietary Safety Restraint System, procon-ten remained from its donor vehicle. Approximately 2200 RS 2s were to be built initially, but due to demand the total was 2891 cars built. Of these, only 180 were right hand drive cars built for the UK, New Zealand and South African markets. Audi also produced an S2 , which was available both as an Avant (estate) and
930-400: The wheels to rotate at different speeds when required. An illustration of the operating principle for a ring-and-pinion differential is shown below. A relatively simple design of differential is used in rear-wheel drive vehicles, whereby a ring gear is driven by a pinion gear connected to the transmission. The functions of this design are to change the axis of rotation by 90 degrees (from
961-409: Was the only transmission choice. Audi's Torsen -based 'trademark' quattro permanent four-wheel drive system was standard. Front and rear final drive units contained a conventional 'open' differential , and have a ratio of 4.111, although the rear (parts code prefix: 01H, identification code: AZE) also has an electro-mechanical diff lock. Porsche-designed braking and suspension systems replaced