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109-571: The Toyota MR2 is a line of two-seater, mid-engined , rear-wheel-drive sports cars , manufactured in Japan and marketed globally by Toyota from 1984 until 2007 over three generations: W10 (1984–1989), W20 (1989–1999) and W30 (1999–2007). It is Japan's first rear mid-engined production car. Conceived as a small, economical and sporty car, the MR2 uses simple but effective design elements, including an inline-four engine , transversely mounted in front of

218-872: A DOHC four-valve-per-cylinder motor, borrowed from the E80 series Corolla . This engine was also equipped with Denso electronic port fuel injection and T-VIS variable intake geometry, giving the engine a maximum power output of 112 hp (84 kW) in the US, 128 hp (95 kW) in the UK, 116 or 124 PS (85 or 91 kW; 114 or 122 hp) in Europe (with or without catalytic converter), 118 hp (88 kW) in Australia and 130 PS (96 kW; 128 hp) in Japan. Japanese models were later detuned to 120 PS (88 kW; 118 hp). A five-speed manual transmission

327-413: A 1.5-liter OHV straight-4 with four valves per cylinder as far back as 1914 but did not use this engine until after World War I . It produced appr. 30 bhp (22.4 kW) at 2700 rpm (15.4 kW/liter or 0.34 bhp/cid). In the 1920 Voiturettes Grand Prix at Le Mans driver Ernest Friderich finished first in a Bugatti Type 13 with the 16-valve engine, averaging 91.96 km/h. Even more successful

436-420: A 1976 Toyota design project with the goal of a car which would be enjoyable to drive, yet still provide good fuel economy – not necessarily a sports car. Design work began in 1979 when Akio Yoshida from Toyota's testing department started to evaluate alternatives for engine placement and drive method, finalizing a mid-transverse engine placement. Toyota called the 1981 prototype SA-X . From its original design,

545-549: A 360.8 cid (5.8-liter) straight-4 (0.22 bhp per cubic inch). Over 2300 of these powerful early multi-valve engines were built. Stutz not only used them in their famous Bearcat sportscar but in their standard touring cars as well. The mono block White Motor Car engine developed 72 horsepower and less than 150 were built, only three are known to exist today. In 1919 Pierce-Arrow introduced its 524.8 cid (8.6-liter) straight-6 with 24 valves. The engine produced 48.6 bhp (0.09 bhp per cubic inch) and ran very quietly, which

654-435: A challenge during testing, as the 222D also suffered from enormous turbo lag (as did most of the competitive Group B cars), but paired with the extremely short wheel base made driving at speed almost impossible. Toyota Team Europe owner Ove Anderson describes: "you never knew what it was going to do. With such a short wheelbase and such power in such a light car it could swap ends at any time, and without any warning". During

763-814: A four valve per cylinder engine was the 1973 Triumph Dolomite Sprint . This Triumph used an in-house developed SOHC 16-valve 1,998 cc (122 ci) straight-4 engine that produced 127 bhp (47.6 kW/liter, 1.10 bhp/cid) at introduction. The 1975 Chevrolet Cosworth Vega featured a DOHC multi-valve head designed by Cosworth Engineering in the UK. This 122-cubic-inch straight-4 produced 110 bhp (82 kW; 112 PS) at 5600 rpm (0.90 bhp/cid; 41.0 kW/liter) and 107 lb⋅ft (145 N⋅m) at 4800 rpm. The 1976 Fiat 131 Abarth (51.6 kW/liter), 1976 Lotus Esprit with Lotus 907 engine (54.6 kW/liter, 1.20 bhp/cid), and 1978 BMW M1 with BMW M88 engine (58.7 kW/liter, 1.29 bhp/cid) all used four valves per cylinder. The BMW M88/3 engine

872-467: A four-valve design. The three-valve design was common in the late 1980s and early 1990s; and from 2004 the main valve arrangement used in Ford F-Series trucks, and Ford SUVs. The Ducati ST3 V-twin had 3-valve heads. This is the most common type of multi-valve head, with two exhaust valves and two similar (or slightly larger) inlet valves. This design allows similar breathing as compared to

981-433: A four-valve engine, a five-valve design should have a higher maximum RPM, and the three inlet ports should give efficient cylinder-filling and high gas turbulence (both desirable traits), it has been questioned whether a five-valve configuration gives a cost-effective benefit over four-valve designs. The rise of direct injection may also make five-valve heads more difficult to engineer, as the injector must take up some space on

1090-445: A handful of 2+2 designs . Additionally, some microtrucks use this layout, with a small, low engine beneath a flat load floor above the rear wheel-wells. This makes it possible to move the cab right to the front of the vehicle, thus increasing the loading area at the expense of slightly reduced load depth. In modern racing cars, RMR is a common configuration and is usually synonymous with "mid-engine". Due to its weight distribution and

1199-632: A multi-valved Golf GTI 16V . The 16-valve 1.8-liter straight-4 produced 139 PS (102 kW; 137 bhp) or 56.7 kW/liter, almost 25% up from the 45.6 kW/liter for the previous 8-valve Golf GTI engine. The GM Quad 4 multi-valve engine family debuted early 1987. The Quad 4 was the first mainstream multi-valve engine to be produced by GM after the Chevrolet Cosworth Vega . The NA Quad 4 achieved 1.08 bhp (1 kW; 1 PS) per cubic inch (49.1 kW/liter). Such engines soon became common as Japanese manufacturers adopted

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1308-460: A private collector in 2017, one in white, with a 50mm lengthened wheelbase and a more production styled body located in Tokyo. Although the 222D was still a prototype, it made it very far into development before Group B was canceled. Of the rumored eleven built, eight were destroyed in testing, indicating Toyota was considering bringing the 222D to competition. However, the short wheelbase proved to be

1417-528: A rallying legend in the 1970s winning many domestic and World Championship events. Other cars claiming to be first are the Jensen Healey , launched in 1972 which used a Lotus 907 belt-driven DOHC 16-valve 2-liter straight-4 producing 140 bhp (54.6 kW/liter, 1.20 bhp/cid). All of these, although mass-produced, are also of relatively limited production, so it is argued that the first widely available and popularly priced mass-production car with

1526-421: A redesign in 1989 (though North America did not receive them until early 1990 as 1991 models). The new car was larger, weighed 350 to 400 lb (159 to 181 kg) more than its predecessor due to having a more luxurious and spacious cabin, larger engine sizes, sturdier transaxle, and a more durable suspension setup. The overall design of the automobile received more rounded, streamlined styling, with some calling

1635-580: A run of 270 units, featured a special Midnight Blue paint, the MOMO -commissioned steering wheel and gear knob, Recaro "Milano" seats with matching door panels. The 1989 model also benefited from some of the last G-Limited model options, such as the LED rear spoiler brake light and more aerodynamic wing mirrors. Both "Super Edition" models had unique decals on the rear visor and side stripes. While Toyota's front-engine, rear-drive Celica rally cars proved dominant in

1744-531: A sign of greater things to come. The 718 followed similarly in 1958. But it was not until the late 1950s that RMR reappeared in Grand Prix (today's " Formula One ") races in the form of the Cooper - Climax (1957), soon followed by cars from BRM and Lotus . Ferrari and Porsche soon made Grand Prix RMR attempts with less initial success. The mid-engined layout was brought back to Indianapolis in 1961 by

1853-408: A slight increase in torque. For homologation Evolution I (1989) and Evolution II (1990) models were produced that had a redesigned engine to allow for a higher rev limit and improved top-end power capabilities. The Evo II engine offered 235 PS (173 kW; 232 hp) from 2463 cc (70.2 kW/liter). Saab introduced a 16-valve head to their 2.0-liter (1985 cc) straight-4 in 1984 and offered

1962-610: A split-plane crankshaft rather than the Ferrari-type flat-plane. The engine was constructed by Ducati rather than Ferrari, and was produced from 1986 through 1991. The Quattrovalvole was also used by Lancia for their attempt at the World Sportscar Championship with the LC2 . The engine was twin-turbocharged and destroked to 2.65 litres, but produced 720 hp (537 kW) in qualifying trim. The engine

2071-408: A surprise appearance at the 2006 Goodwood Festival of Speed , Toyota drove and displayed a black 222D. The race-ready car weighed around 750 kg (1,650 lb) and its transverse-mounted, four-cylinder, turbocharged engine (what appears to be a 503E race engine, though other prototypes may have used the 4T-GTE ) was reported to produce as much as 750 hp (559 kW). The MR2 went through

2180-407: A three-valve head, and as the small exhaust valves allow high RPM, this design is very suitable for high power outputs. Less common is the five-valve head, with two exhaust valves and three inlet valves. All five valves are similar in size. This design allows excellent breathing, and, as every valve is small, high RPM and very high power outputs are theoretically available. Although, compared to

2289-428: A time also produced a brake kit as well for the MR2, but this has been discontinued. Performance parts manufacturer JUN offered engine upgrades for the MR2's 3S-GTE engine which came in the form of stroker kits, which were co-developed with Cosworth , and also offered lightened flywheels, cam gears, and camshafts. The SW20 garnered generally favorable reviews during its production life, with various sources complimenting

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2398-469: A two-valve design, Toyota and Yamaha changed the 4A-GE to a four-valve after a year of evaluation. It produced 115-140 bhp (86-104 kW) at 6,600 rpm (54.2-65.5 kW/liter) and 109 lb⋅ft (148 N⋅m) at 5,800 rpm. To compensate for the reduced air speed of a multi-valve engine at low rpms, the first-to-second generation engines included the T-VIS intake system. In 1986 Volkswagen introduced

2507-416: A two-valve engine, delivering more power . A multi-valve engine design has three, four, or five valves per cylinder to achieve improved performance. In automotive engineering , any four-stroke internal combustion engine needs at least two valves per cylinder: one for intake of air (and often fuel ), and another for exhaust of combustion gases. Adding more valves increases valve area and improves

2616-482: A variety of changes during its 10 years of production, grouped in four different periods: Introduction of the new generation. Revision 5 : 1998–1999 Model (Introduced Nov-1997): Changes to the suspension geometry, tire sizes and power steering in January 1992 (MY 1993) were made in response to journalist reports that the MR2 was prone to "snap-oversteer" . As a counterpoint to the snap-oversteer phenomenon of

2725-424: A variety of tuning parts for the MR2. The "T020" as it was called, was powered by a naturally aspirated 2.2L stroked 3S-GE that produced 175 kW (235 bhp) at 6,800 rpm, this was due to more aggressive "F3" cams, a stroker kit, better intake flow with the aid of the "TOM'S Hyper Induction Carbon" intake kit, and an upgraded exhaust system labeled the "TOM'S Barrel", a lightened flywheel was also equipped to help

2834-531: A very favorable balance, with plenty of weight on the driven rear axle under acceleration, while distributing the weight fairly evenly under braking, thereby making optimal use of all four wheels to decelerate the car rapidly as well. The RMR layout generally has a lower tendency to understeer . However, since there is less weight over the front wheels, under acceleration the front of the car can be prone to lift and still have understeer . Most rear-engine layouts have historically been used in smaller vehicles, because

2943-464: Is also used to improve engine performance. The 1908 Ariès VT race cars had 1.4 litre supercharged single cylinder engines with four valve per cylinder desmodromic systems. (Source: [1] ) The 1910 Isotta-Fraschini Tipo KM had a 10.6 litre inline 4 with single overhead camshaft and four valves per cylinder and it had one of the first engines with fully enclosed overhead valve gear (source: Isotta Fraschini Tipo KM [1] and [2] ) The first motorcar in

3052-444: Is rumored that approximately 10 conversion kits were imported from TRD Japan into the US for conversions. In many respects, the extended body can be compared to that of a Porsche 911 Slantnose modification. The car's width is extended and body dimensions dramatically changing the car's overall visuals. Very little is known about these cars outside Japan. Apart from Toyota Racing Development, TOM'S also released official body kits and

3161-588: Is rumored that at least one was built to produce up to 373 kW (500 bhp) whereas some others had few modifications to their engines. In order to ensure exclusivity, a high price tag was charged and total of just 35 factory car conversions were completed by Toyota Technocraft Ltd. Each official Technocraft-converted car was made using lightweight fiberglass components (front fenders, trunk lid extension, rear quarter panels, gas door, front and rear bumpers, 3-piece wing) and re-classified as completely new cars (with their own specially numbered TRD VIN plate riveted to

3270-639: The 1923 Benz Tropfenwagen . It was based on an earlier design named the Rumpler Tropfenwagen in 1921 made by Edmund von Rumpler , an Austrian engineer working at Daimler. The Benz Tropfenwagen was designed by Ferdinand Porsche along with Willy Walb and Hans Nibel . It raced in 1923 and 1924 and was most successful in the Italian Grand Prix in Monza where it stood fourth. Later, Ferdinand Porsche used mid-engine design concept towards

3379-497: The Auto Union Grand Prix cars of the 1930s which became the first winning RMR racers. They were decades before their time, although MR Miller Specials raced a few times at Indianapolis between 1939 and 1947. In 1953 Porsche premiered the tiny and altogether new RMR 550 Spyder and in a year it was notoriously winning in the smaller sports and endurance race car classes against much larger cars –

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3488-605: The Cooper Car Company with Jack Brabham running as high as third and finishing ninth. Cooper did not return, but from 1963 on British built mid-engined cars from constructors like Brabham , Lotus and Lola competed regularly and in 1965 Lotus won Indy with their Type 38 . Rear mid-engines were widely used in microcars like the Isetta or the Zündapp Janus . The first rear mid-engined road car after WW II

3597-533: The Mazda B8-ME ) use a single fork-shaped rocker arm to drive two valves (generally the exhaust valves) so that fewer cam lobes will be needed in order to reduce manufacturing costs. This has a single large exhaust valve and two smaller intake valves. A three-valve layout allows better breathing than a two-valve head, but the large exhaust valve results in an RPM limit no higher than a two-valve head. The manufacturing cost for this design can be lower than for

3706-848: The R-series engines, the Mazda B8-ME , and the Chrysler 3.5 L V6 engine . The V12 engines of many World War II fighter aircraft also used a SOHC configuration with four valves for each cylinder. The 1993 Mercedes-Benz C-Class (OM604 engine) was the first 4-valve diesel-engined car. Peugeot had a triple overhead cam five-valve Grand Prix car in 1921. In April 1988 an Audi 200 Turbo Quattro powered by an experimental 2.2-liter turbocharged 25-valve straight-5 rated at 478 kW/650 PS@6,200 rpm (217.3 kW/liter) set two world speed records at Nardo , Italy: 326.403 km/h (202.8 mph) for 1,000 km (625 miles) and 324.509 km/h (201.6 mph) for 500 miles. Mitsubishi were

3815-572: The Stutz Motor Company introduced a 322 cid (5.3-liter) dual camshaft 32-valve straight-8 with 156 bhp (116 kW) at 3900 rpm, called DV-32. The engine offered 0.48 bhp per cubic inch. About 100 of these multi-valve engines were built. Stutz also used them in their top-of-the-line sportscar, the DV-32 Super Bearcat that could reach 100 mph (160 km/h). The 1935 Duesenberg SJ Mormon Meteor's engine

3924-464: The gearbox and differential . This represented an extremely innovative sportscar at a time when all of its competitors (aside from the rear-engined Porsches), from Ferraris to Aston Martins , were traditional front-engined, rear-wheel-drive grand tourers. The Pontiac Fiero was a mid-engined sports car that was built by the Pontiac division of General Motors from 1984 to 1988. The Fiero

4033-490: The "Turbo" emblem (US) on the rear trunk, 'TWIN CAM 16 TURBO' decal above the side intake (Japanese market), a fiberglass engine lid with raised vents, fog lights, and an added interior center storage compartment located between the two seats. All SW20 MR2s came with a staggered wheel setup, with wider wheels and tires in the rear than in the front. Mechanical differences on the Turbo models include: The US market MR2 Turbo model

4142-513: The 190 E 2.3-16 produced 49 hp (36 kW) and 41 ft•lbf (55 N•m) of torque more than the basic single overhead cam 2.3 straight-4 engine on which it was based offering 185 hp (138 kW) at 6,200 rpm (59.2 kW/liter) and 174 lb⋅ft (236 N⋅m) at 4,500 rpm. In 1988 an enlarged 2.5-liter engine replaced the 2.3-liter. It offered double valve timing chains to fix the easily snapping single chains on early 2.3 engines, and increased peak output by 17 bhp (12.5 kW) with

4251-437: The 1917 Stutz straight-4, White Motor Car Model GL 327 CID Dual Valve Mononblock four, and 1919 Pierce-Arrow straight-6 engines. The standard flathead engines of that day were not very efficient and designers tried to improve engine performance by using multiple valves. The Stutz Motor Company used a modified T-head with 16 valves, twin-spark ignition and aluminium pistons to produce 80 bhp (59 kW) at 2400 rpm from

4360-510: The 1920s when these DOHC engines came to Alfa road cars like the Alfa Romeo 6C . In 1916 US automotive magazine Automobile Topics described a four-cylinder, four-valve-per-cylinder car engine made by Linthwaite-Hussey Motor Co. of Los Angeles, CA, USA: "Firm offers two models of high-speed motor with twin intakes and exhausts." . Early multi-valve engines in T-head configuration were

4469-438: The 1922 Type 29 Grand Prix racer and the legendary Type 35 of 1924. Both Type 29 and Type 35 had a 100 bhp (75 kW) 2-liter SOHC 24-valve NA straight-8 that produced 0.82 bhp (0.61 kW) per cubic inch. A.L.F.A. 40/60 GP was a fully working early racing car prototype made by the company now called Alfa Romeo . Only one example was built in 1914, which was later modified in 1921. This design of Giuseppe Merosi

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4578-411: The 911 (993) GT2 for increased downforce at high speeds, and a reworked suspension set up with Öhlins equipment. Japanese tuner Border Racing, made available several parts as well, consisting mostly of parts that improved the car's suspension geometry, namely roll-center adapters, extended tie rods, etc., though they have also produced intercooler kits for the car and several interior pieces. AP Racing at

4687-520: The African Group B rallies of the 1980s, they were at a disadvantage on the twistier European stages. Thus, Toyota Team Europe started a rally project in 1985, codenamed "222D" based on the MR2, for competition in Group S and potentially Group B. Though somewhat similar on the outside, it is clear that the prototype had very little in common with the production car although the two appear to share

4796-636: The Frankfurt Auto Show in September 1983 after it set a world record at Nardo, Italy, recording a combined average speed of 154.06 mph (247.94 km/h) over the 50,000 km (31,000 mi) endurance test. The engine was based on the 2.3-liter 8-valve 136 hp (101 kW) unit already fitted to the 190- and E-Class series. Cosworth developed the DOHC light alloy cast cylinder head with four large valves per cylinder. In roadgoing trim,

4905-608: The Honda NSX, Toyota Supra RZ, and even the Ferrari 348 TB . Best Motoring, a popular Japanese automobile TV show, featured an episode that had them battle a factory stock Rev 5 GT-S Turbo versus other Japanese market contemporaries on the Tsukuba Circuit , with the MR2 winning the circuit race. In the rankings of personal bests, a Rev 2 GT-S was able to clock 1:08.00 at Tsukuba Circuit. The second-generation MR2 underwent

5014-559: The MR2 SW20 a "baby Ferrari" or "poor man's Ferrari" due to design cues similar to the Ferrari 308 GTB/GTS or Ferrari 348 . Like the AW11 before it, Toyota spent countless hours fine-tuning the handling capabilities of the SW20, seeking advice from professional race car drivers, including Dan Gurney of Formula One, NASCAR, and Le Mans fame. When the AW11 was still in production and before

5123-669: The MR2 community. TOM'S still keeps a T020 part list on their website, and there are still T020 part catalogues in circulation between enthusiasts to this day, albeit second-hand. Between 1996 and 1999, Toyota TechnoCraft (TTC) produced 88 or 91 SW20 MR2 Spider convertible conversions. These cars featured a retractable cloth softtop roof and exclusive wingless trunk and engine lids. Most Spiders had automatic transmissions, naturally aspirated engines, and Lucerne Silver paint with blue side mouldings and black and blue accented cloth seats. The Toyota name and logo were not applied to these cars due to concerns about roof leaks. During its production,

5232-459: The MR2 number eight on the list of Top Sports Cars of the 1980s . In 1988 and 1989 Toyota produced two final production runs of fully optioned "Super Edition" MR2s, based upon the supercharged Japanese market model, and only sold in Japan. The 1988 'Super Edition' was a run of 300 units, had white/gold two-tone paint, bronze glass, unique half-leather and half-cloth seats, along with a MOMO -commissioned steering wheel and gear knob. The 1989 model,

5341-645: The MR2 won the Car of the Year Japan . As Toyota engineered the MR2 to accommodate a 2-liter engine, its primary features included its light body (as low as 950 kg (2,094 lb) in Japan and 1,066 kg (2,350 lb) in the US), strong handling, and low-power small-displacement engine. The car is often referred to as the AW11, referring to the chassis code of the most common 1.6-liter, A-engined versions. The MR2's suspension and handling were designed by Toyota with

5450-399: The MR2, other journalists point out that most mid-engine and rear-engine sports and super cars exhibit similar behaviour, and that a change to the driver's response to oversteer is really the solution. In any car, braking shifts the weight forward, and acceleration to the rear. When drivers enter a corner with too much speed, and lift the throttle mid-corner, the weight transfers forward causing

5559-610: The Renault-engined Lotus Europa , built from 1966 to 1975. Finally, in 1966, the Lamborghini Miura was the first high performance mid-engine, rear-wheel-drive road car. The concept behind the Miura was that of putting on the road a grand tourer featuring state-of-the-art racing-car technology of the time; hence the Miura was powered by a V12 transversely mounted between the rear wheels, solidal to

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5668-450: The SW20 chassis a much more capable track machine. A sportier look was given to the vehicle as well through engine scoops, side skirts, a Ferrari 348 -esque rear light grille, forged wheels, revised bumper designs, and a larger rear spoiler. Though undeniably still an MR2, the T020 was in all essence a more refined automobile, as is the nature of any TOM'S outfitted vehicle. Whilst the T020

5777-407: The SW20 enjoyed a myriad of tuning parts from Japanese tuners such as HKS, Blitz, Phoenix Power, etc. While some companies only offered aesthetic modifications for the SW20, others such as Phoenix Power offered modifications such as a tuned ECU, longblock modifications, and a trunk-mounted intercooler combined with a T04R Turbocharger. The Phoenix Power MR2 also featured a large rear wing reminiscent of

5886-437: The SW20 still has a large enough following to be labeled as a very challenging car to push to its limits, with some labeling it as "the most dangerous car that you can buy". Such a label may be true as MR2s are relatively cheaper than most automobiles with an MR platform ( Honda NSX , Ferrari F355 , Lotus Elise ) and that it is readily available to most people. Early in the 1990s, the SW20 enjoyed considerable success throughout

5995-476: The SW20 was officially shown to the public, several rumors were spreading stating that Toyota was building yet another mid-engine sports car, one that would have a 3.0-liter V6 engine that could directly compete with the 348, though this specific rumor was later shot down under the pretense that such a car would belong under the Lexus branding. Differences between the normally aspirated and turbocharged models include

6104-542: The TRD2000GT wins in the GT-C Japanese racing series, since the TRD2000GT racing series cars were based on the SW20 floor pan. The TRD2000GT body kit widened the MR2 by a total of 100 mm (4 in). Prior to MR2s being fitted with the TRD2000GT body kit, TRD had its customers select which additional engine, suspension, wheel, and interior upgrades they wanted. For this reason, no two TRD2000GT MR2s are alike. It

6213-420: The US market), Toyota introduced a supercharged engine for the MR2. Based on the same block and head, the 4A-GZE was equipped with a small Roots-type supercharger and a Denso intercooler . T-VIS was eliminated and the compression ratio was lowered to 8:1. It produced 145 hp (147 PS; 108 kW) at 6,400 rpm and 186 N⋅m; 137 lb⋅ft (19 kg⋅m) of torque at 4,400 rpm and accelerated

6322-586: The added cost of a DOHC valve train . The Ford design uses one spark plug per cylinder located in the centre, but the Mercedes design uses two spark plugs per cylinder located on opposite sides, leaving the centre free to add a direct-to-cylinder fuel injector at a later date. The 1989 Citroën XM was the first 3-valve diesel-engined car. Examples of SOHC four-valve engines include the Honda F-series engines, D-series engines, all J-series engines,

6431-415: The body to indicate their authenticity and rarity). The Toyota Technocraft Ltd. TRD2000GT had a 60 mm (2.4 in) wider front and rear track (due to the addition of wider wheels and tires). Virtually every car converted also had other TRD parts fitted too, including extensive changes to both the suspension and engine. Most cars left the factory making more power due to TRD bolt-ons, some cars even left

6540-402: The car evolved into a sports car, and further prototypes were tested both in Japan and in the US. Significant testing was performed on race circuits including Willow Springs , where former Formula One driver Dan Gurney tested the car. All three generations were in compliance with Japanese government regulations concerning exterior dimensions and engine displacement. The MR2 appeared around

6649-416: The car from 0 to 100 km/h (62 mph) in 6.5 to 7.0 seconds. The supercharger was belt-driven but actuated by an electromagnetic clutch, so that it would not be driven except when needed, increasing fuel economy. Curb weight increased to as much as 2,494 lb (1,131 kg) for supercharged models, due to the weight of the supercharger equipment and a new, stronger transmission. A fuel selector switch

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6758-403: The change and claim that it "neutered" the sharp edge the MR2 was known for. Toyota claimed that the changes were made "for drivers whose reflexes were not those of Formula One drivers". In 1998, Toyota Racing Development offered an official kit body conversion and tuning program for MR2 owners to transform their existing SW20 MR2 into a wide-body TRD2000GT replica car. This was to pay homage to

6867-501: The danger of valve float . Some engines are designed to open each intake valve at a slightly different time, which increases turbulence, improving the mixing of air and fuel at low engine speeds. More valves also provide additional cooling to the cylinder head. The disadvantages of multi-valve engines are an increase in manufacturing cost and a potential increase in oil consumption due to the greater number of valve stem seals. Some single overhead camshaft (SOHC) multi-valve engines (such as

6976-477: The early 2000s. SARD (Sigma Advanced Research Development) built a heavily modified and lengthened version of the SW20 for GT racing called the SARD MC8-R. It used a heavily modified MR2 frontal chassis with a custom rear chassis made to fit a twin-turbo version of the 4.0-liter 1UZ-FE V8 producing 600 bhp (447 kW). This is the first car which only used the frontal chassis of a production car and

7085-486: The engine rev easier. The T020 also featured a more race-oriented suspension/chassis set up via camber kits, upgraded tie-rods, strut bars, roll center adjusters, stiffer springs, race shock absorbers, and sports brake pads. These modifications lowered the vehicle's center of gravity for increased agility and stability while cornering, and combined with the engine modifications enabling the T020 to accelerate from 0–60 mph (0–97 km/h) in 4.9 seconds, in turn further made

7194-552: The engine with and without turbocharger (65.5 kW/liter and 47.9 kW/liter respectively) in the Saab 900 and Saab 9000 . The 2.0-liter Nissan FJ20 was one of the earliest straight-4 mass-produced Japanese engines to have both a DOHC 16-valve configuration (four valves per cylinder, two intake, two exhaust) and electronic fuel injection (EFI) when released in October 1981 in the sixth generation Nissan Skyline . Peak output

7303-461: The factory boasting up to 500 PS (368 kW; 493 hp) and less than 1100 kg (2425 lb) for a very impressive power-to-weight ratio. While TRD Japan only offered a small number of kits with all body parts required for third-party conversion, Toyota Technocraft Ltd. offered complete car conversions. Apart from the cars listed on the TRD2000GT register it is unknown how many original Toyota Technocraft Ltd. cars still exist today, but it

7412-489: The favorable vehicle dynamics it produces, this layout is heavily employed in open-wheel Formula racing cars (such as Formula One and IndyCar ) as well as most purpose-built sports racing cars . This configuration was also common in smaller-engined 1950s microcars , in which the engines did not take up much space. Because of successes in motorsport, the RMR platform has been commonly used in many road-going sports cars despite

7521-669: The first appears to have been the 1969 Nissan Skyline , using the Nissan S20 six cylinder DOHC four-valve engine. This engine was also fitted to Nissan Fairlady Z432 racing edition. For a four-cylinder engine, the first mass-produced car using a four valves per cylinder engine was the British Ford Escort RS1600 , this car used the Cosworth BDA engine which was a Ford 'Kent' block with a Cosworth 16 valve twin cam cylinder head. The car went on to become

7630-415: The flow of intake and exhaust gases, thereby enhancing combustion , volumetric efficiency , and power output . Multi-valve geometry allows the spark plug to be ideally located within the combustion chamber for optimal flame propagation. Multi-valve engines tend to have smaller valves that have lower reciprocating mass , which can reduce wear on each cam lobe, and allow more power from higher RPM without

7739-424: The fully rear-engine, rear-wheel-drive layout , the center of mass of the engine is in front of the rear axle. This layout is typically chosen for its favorable weight distribution . Placing the car's heaviest component within the wheelbase minimizes its rotational inertia around the vertical axis, facilitating turn-in or yaw angle . Also, a near 50/50% weight distribution, with a slight rear weight bias, gives

7848-493: The head. After making five-valve Genesis engines for several years, Yamaha has since reverted to the cheaper four-valve design. Examples of the five-valve engines are the various 1.8 L 20vT engines manufactured by AUDI AG, the later versions of the Ferrari Dino V8 , and the 1.6 L 20-valve 4A-GE engine made by Toyota in collaboration with Yamaha. For a cylindrical bore and equal-area sized valves, increasing

7957-476: The help of Lotus engineer Roger Becker. Toyota's cooperation with Lotus during the prototype phase can be seen in the AW11, and it owes much to Lotus's sports cars of the 1960s and 1970s. Toyota's active suspension technology, called TEMS , was not installed. With five structural bulkheads, the MR2 was quite heavy for a two-seater of its size. Toyota employed the naturally aspirated 4A-GE 1,587 cc (1.6 L; 96.8 cu in) inline-four engine ,

8066-451: The inherent challenges of design, maintenance and lack of cargo space. The similar mid-engine, four-wheel-drive layout gives many of the same advantages and is used when extra traction is desired, such as in some supercars and in the Group B rally cars. The 1900 NW Rennzweier was one of the first race cars with mid-engine, rear-wheel-drive layout. Other known historical examples include

8175-522: The most notable being that rear suspension components are not interchangeable between the MK1a and MK1b cars. Original introduction The changes in MY 1986 and MY 1987 occurred in parts. Instead of a drastic change in MY 1987 models for the above MK1b upgrades, some MK1a parts continued on in early MY 1987 cars while some MK1b parts came on MY 1986 cars as options. An example is that some MY 1987 cars still retained

8284-513: The multi-valve concept. The 1975 Honda Civic introduced Honda's 1.5-liter SOHC 12-valve straight-4 engines. Nissan's 1988–1992 SOHC KA24E engine had three valves per cylinder (two intakes, one exhaust) as well. Nissan upgraded to DOHC after 1992 for some of their sports cars, including the 240SX . In 1988, Renault released a 12 valve version of its Douvrin 4 cylinder 2.0l SOHC. Mercedes and Ford produced three-valve V6 and V8 engines, Ford claiming an 80% improvement in high RPM breathing without

8393-435: The name MR2. Toyota introduced the first-generation MR2 in 1984, designating it the model code " W10 ". When fitted with the 1.5-liter 3A engine, it was known as the "AW10". Likewise, the 1.6-liter 4A version is identified by the "AW11" code. In Japan, the MR2 was marketed exclusively via Toyota's Toyota Auto Store and Toyota Vista Store , both rebranded in 1998 as Netz Toyota Store . At its introduction in 1984,

8502-913: The number of valves beyond five decreases the total valve area. The following table shows the effective areas of differing valve quantities as proportion of cylinder bore. These percentages are based on simple geometry and do not take into account orifices for spark plugs or injectors, but these voids will usually be sited in the "dead space" unavailable for valves. Also, in practice, intake valves are often larger than exhaust valves in heads with an even number of valves-per-cylinder: Turbocharging and supercharging are technologies that also improve engine breathing, and can be used instead of, or in conjunction with, multi-valve engines. The same applies to variable valve timing and variable-length intake manifolds . Rotary valves also offer improved engine breathing and high rev performance but these were never very successful. Cylinder head porting , as part of engine tuning ,

8611-414: The old "flat" front bumper despite having MK1b upgrades everywhere else on the car. Some early MY 1987 7-rib engines came with the earlier blue top valve cover. This was also noticed in the rear sway bar removal for the MY 1986. Some MY 1986 cars have a rear sway bar, while the mounting tabs on the strut housing were either there for both sides, only one side, or none at all depending on when Toyota ran out of

8720-521: The older rear struts with mounting tabs as production used up parts. American car magazines Road & Track and Car and Driver both chose the MR2 on their "ten best" car lists. The Australian Wheels magazine chose the 1988 MR2 as its favourite sports car. The MR2 was Motor Trend ' s Import Car of the Year for 1985. The MR2 was also on Car and Driver magazine's Ten Best list for 1986 and 1987. In 2004, Sports Car International ranked

8829-592: The original 300 PS (221 kW; 296 hp) 3.0-liter version the Toyota 7 engine participated in endurance races as a 5.0-liter (4,968 cc) non-turbo V8 with DOHC and 32-valves. It produced 600 PS (441 kW; 592 hp) at 8,000 rpm (88.8 kW/liter) and 55.0 kg⋅m (539 N⋅m; 398 lb⋅ft) at 6,400 rpm. There is much discussion about which was the first 'mass-produced' car to use an engine with four valves per cylinder. For six cylinder engines, and considering special versions of mass-produced cars,

8938-490: The rear axle, four-wheel disc brakes , and fully independent coilover suspension – MacPherson strut fronts and Chapman strut rears. The name MR2 stands for either " m id-ship r un-about 2 -seater" or " m id-engine, r ear-wheel-drive, 2 -seater". In French-speaking markets, the vehicle was renamed Toyota MR because the abbreviation "MR2" sounds like the profanity "merde" when spoken in French. The MR2 derived from

9047-423: The rear tires to lose traction (called lift-off oversteer), which can result in a spin. When improper steering inputs were made attempting to correct this non-power-on oversteer, the rear of the MR2 would swing one way, then wildly (and quickly) the other—thus the term "snap" oversteer. Toyota elected to change the MR2 suspension and tires to reduce the likelihood that this would occur, though many drivers would lament

9156-479: The rear trunk and body mouldings behind both doors. This model was never offered outside of the Japanese and North American markets, although some cars were privately imported to other countries. MK1a and MK1b are unofficial designations, but are frequently used by owners and vendors to distinguish between early production vehicles and later face-lifted models. While there are considerable differences detailed below,

9265-523: The same factory AW11 floor pan. Little else is known about the project as it never competed. With Group B cancelled in 1986, the proposed Group S regulations suffered the same fate, and the remaining prototypes were reduced to museum pieces and private collections. Supposedly eleven prototypes were made, of which eight were destroyed during testing, leaving only three known examples: Two in black, one stored at Toyota Gazoo's facility in Cologne and one sold to

9374-716: The same time as the Honda CR-X and the Nissan EXA from Japan, the Pontiac Fiero and Ford EXP from North America, and about a decade after the VW Scirocco and Fiat X1/9 from Europe made their debut. Toyota debuted its SV-3 concept car in October 1983 at the Tokyo Motor Show , gathering press and audience publicity. The car was scheduled for a Japanese launch in the second quarter of 1984 under

9483-402: The spark plugs. Only two cars were built. Ferrari developed their Quattrovalvole (or QV) engines in the 80s. Four valves per cylinder were added for the 1982 308 and Mondial Quattrovalvole , bringing power back up to the pre- FI high of 245 hp (183 kW) . A very unusual Dino Quattrovalvole was used in the 1986 Lancia Thema 8.32 . It was based on the 308 QV's engine, but used

9592-415: The styling, power, and responsive handling. Car and Driver noted the revised SW20's braking capabilities to be superb, stating that 70 mph to standstill could be done in 157 feet, rivaling that of the Honda NSX. Former Top Gear host and racing driver Tiff Needell commends the SW20's handling having said that it "encourages you to drive with enthusiasm" in a review back in 1990. He does note however, that

9701-449: The sudden transition from understeer to oversteer may be startling for some people. The car is infamously known for its "snap-oversteer" phenomenon. This notoriety comes from numerous instances where individuals crash their SW20s either on or off the race track due to inexperience with a mid-ship platform, as MR layouts handle very differently in comparison to the more common FF or even FR layouts. Even in its revised state from January 1992,

9810-412: The weight of the engine at the rear has an adverse effect on a larger car's handling, making it 'tail-heavy', although this effect is more pronounced with engines mounted behind the rear axle. It is felt that the low polar inertia is crucial in selection of this layout. The mid-engined layout also uses up central space, making it generally only practical for single seating-row sports-cars, with exception to

9919-516: The world speed record of 170 km/h. Robert Peugeot also commissioned the young Ettore Bugatti to develop a GP racing car for the 1912 Grand Prix. This chain-driven Bugatti Type 18 had a 5-litre straight-4 with SOHC and three valves per cylinder (two inlet, one exhaust). It produced appr. 100 bhp (75 kW; 101 PS) at 2800 rpm (0.30 bhp per cubic inch) and could reach 99 mph (159 km/h). The three-valve head would later be used for some of Bugatti's most famous cars, including

10028-551: The world to have an engine with two overhead camshafts and four valves per cylinder was the 1912 Peugeot L76 Grand Prix race car designed by Ernest Henry . Its 7.6-litre monobloc straight-4 with modern hemispherical combustion chambers produced 148 bhp (110 kW) (19.5 HP/Liter(0.32 bhp per cubic inch)). In April 1913, on the Brooklands racetrack in England, a specially built L76 called "la Torpille" (torpedo) beat

10137-673: The world. Several teams fielded the MR2 in the Swiss Touring Car Championship, as well as in the South-East Asian Supercar Championship, with much success. The chassis was also used for a time during the mid 90s in the Fuji Freshman Series in Japan in which the SW20 succeeded the earlier AE86 chassis. As of 2022, both the SW20 and ZZW30 chassis are used in 750 Motor Club's MR2 Championship in the UK which started in

10246-464: Was 148 hp (110 kW) at 6,000 rpm and 133 lb⋅ft (180 N⋅m) at 4,800 rpm. The FJ20 was also offered with a turbocharger, producing 188 hp (140 kW) at 6,400 rpm and 166 lb⋅ft (225 N⋅m) at 4,800 rpm. Following Nissan's lead, Toyota released the 1.6-liter (1,587 cc) 4A-GE engine in 1983. The cylinder head was developed by Yamaha Motor Corporation and was built at Toyota's Shimayama plant. While originally conceived of as

10355-605: Was Bugattis clean sweep of the first four places at Brescia in 1921. In honour of this memorable victory all 16-valve-engined Bugattis were dubbed Brescia . From 1920 through 1926 about 2000 were built. Peugeot had a triple overhead cam 5-valve Grand Prix car in 1921. Bentley used multi-valve engines from the beginning. The Bentley 3 Litre , introduced in 1921, used a monobloc straight-4 with aluminium pistons, pent-roof combustion chambers , twin spark ignition, SOHC, and four valves per cylinder. It produced appr. 70 bhp (0.38 bhp per cubic inch). The 1927 Bentley 4½ Litre

10464-468: Was a 419.6 cid (6.9-liter) straight-8 with DOHC, 4 valves per cylinder and a supercharger. It achieved 400 bhp (298.3 kW) at 5,000 rpm and 0.95 bhp per cubic inch. The 1937 Mercedes-Benz W125 racing car used a supercharged 5.7-liter straight-8 with DOHC and four valves per cylinder. The engine produced 592-646 bhp (441.5-475 kW) at 5800 rpm and achieved 1.71-1.87 bhp per cubic inch (77.8-85.1 kW/liter). The W125 top speed

10573-415: Was a normally aspirated vehicle, TOM'S also produced equipment for turbocharged models — e.g. wastegates, boost controllers, air filters, a 3S-GTE version of their "TOM'S Barrel" exhaust system, and "T.E.C. II" Engine Control Units. Despite the fact that these products are no longer purchasable brand new, some of these modification parts may still be procured as second-hand items, and are highly sought after by

10682-600: Was able to accelerate from 0–60 mph (0–97 km/h) in 6.1 seconds and finish the 1/4 mile in 14.7 seconds. The Revision 1 Turbo SW20 can pull 0.89g at the skidpad, with later revisions averaging 0.90g – 0.94. Revision 2 cars were fitted with Yokohama A022s; coincidentally, the Honda NSX also uses a special variant of the A022. A Japanese market Rev 3 GT-S Turbo was able to run the 1/4 mile in 13.1 seconds, beating out more expensive and higher powered automobiles such as

10791-458: Was also added in some markets, to allow the car to run on regular unleaded fuel if required. In addition to the new engine, the MR2 SC was also equipped with stiffer springs, and received special "tear-drop" aluminum wheels. The engine cover had two raised vents (only one of which was functional) that visually distinguished it from the naturally aspirated models. It was also labeled "SUPER CHARGER" on

10900-531: Was an asset to the bootleggers of that era. Multi-valve engines continued to be popular in racing and sports engines. Robert M. Roof, the chief engineer for Laurel Motors, designed his multi-valve Roof Racing Overheads early in the 20th century. Type A 16-valve heads were successful in the teens, Type B was offered in 1918 and Type C 16-valve in 1923. Frank Lockhart drove a Type C overhead cam car to victory in Indiana in 1926. Bugatti also had developed

11009-484: Was appr. 200 mph (322 km/h). The 1967 Cosworth DFV F1 engine, a NA 3.0-liter V8 producing appr. 400 bhp (298 kW; 406 PS) at 9,000 rpm (101.9 kW/liter), featured four valves per cylinder. For many years it was the dominant engine in Formula One, and it was also used in other categories, including CART , Formula 3000 and Sportscar racing . Debuting at the 1968 Japanese Grand Prix in

11118-476: Was effectively a purpose-built semi- sports-prototype that successfully got GT1 homologation. The overall construction method of this car (a heavily modified production car frontal chassis with race-built rear chassis combined into a style of semi-prototype) inspired Porsche to make 911 GT1 homologation specials which dominates the GT1, and foreshadowed the cancellation of GT1. MR layout In contrast to

11227-497: Was later increased to 3.0 litres and increased power output to 828 hp (617 kW). The 1984 Ferrari Testarossa had a 4.9-liter flat-12 with four valves per cylinder. Almost 7,200 Testarossa were produced between 1984 and 1991. In 1985 Lamborghini released a Countach Quattrovalvole , producing 455 PS (335 kW; 449 hp) from a 5.2-liter (5167 cc) Lamborghini V12 engine (64.8 kW/liter). The Mercedes-Benz 190E 2.3-16 with 16-valve engine debuted at

11336-492: Was of similar engine design. The NA racing model offered 130 bhp (0.48 bhp per cubic inch) and the 1929 supercharged 4½ Litre (Blower Bentley) reached 240 bhp (0.89 bhp per cubic inch). The 1926 Bentley 6½ Litre added two cylinders to the monobloc straight-4. This multi-valve straight-6 offered 180-200 bhp (0.45-0.50 bhp per cubic inch). The 1930 Bentley 8 Litre multi-valve straight-6 produced appr. 220 bhp (0.45 bhp per cubic inch). In 1931

11445-573: Was standard, with a four-speed automatic available as an option. Road tests delivered 0–60 mph (97 km/h) times in the mid- to high-8 second range and 1 ⁄ 4 mile (402 m) times in the mid- to high-16 second range, significantly faster than the four-cylinder Pontiac Fiero or Fiat X1/9 . In the home market, the AW10 base model was offered, which used the more economical 1,452 cc (1.5 L; 88.6 cu in) 3A-U engine rated at 61 kW (82 hp). In 1986 (1988 for

11554-533: Was the 1962 (Rene) Bonnet / Matra Djet , which used the 1108cc Renault Sierra engine, mated to the transaxle from the FWD Renault Estafette van. Nearly 1700 were built until 1967. This was followed by the first De Tomaso, the Vallelunga , which mated a tuned Ford Cortina 1500 Kent engine to a VW transaxle with Hewland gearsets. Introduced at Turin in 1963, 58 were built 1964–68. A similar car was

11663-401: Was the first Alfa Romeo DOHC engine. It had four valves per cylinder, 90-degree valve angle and twin-spark ignition. The GP engine had a displacement of 4.5-liter (4490 cc) and produced 88 bhp (66 kW) at 2950 rpm (14.7 kW/liter), and after modifications in 1921 102 bhp (76 kW) at 3000 rpm. The top speed of this car was 88-93 mph (140–149 km/h). It wasn't until

11772-477: Was the first two-seater Pontiac since the 1926 to 1938 coupes, and also the first mass-produced mid-engine sports car by a U.S. manufacturer. Multi-valve#Four valves A multi-valve or multivalve engine is one where each cylinder has more than two valves (an intake , and an exhaust ). A multi-valve engine has better breathing, and with more smaller valves (having less mass in motion) may be able to operate at higher revolutions per minute (RPM) than

11881-405: Was used in the 1983 BMW M6 35CSi and in the 1985 BMW M5 . The 1978 Porsche 935/78 racer used a twin turbo 3.2-liter flat-6 (845 bhp/630 kW@8,200 rpm; 784 Nm/578 ft.lbs@6,600 rpm). The water-cooled engine featured four valves per cylinder and output a massive 196.2 kW/liter. Porsche had to abandon its traditional aircooling because the multi-valve DOHC hampered aircooling of

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