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    History of MK III


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    History of MK III

    Post  SMP-VP on Sun Mar 15, 2009 11:23 pm

    n the middle of 1986, Toyota was ready to release its next version of the Supra. The official model year is designated as 1986.5. The bonds between the Celica and the Supra were cut; they were now two completely different models. The Celica changed to front wheel drive, while the Supra kept its rear wheel drive platform. Though the Mark II and Mark III had similar designs, the engine was updated to a more powerful 3.0 200 hp (149 kW) inline 6. Although only available in naturally aspirated trim in 1986.5, a turbocharged version of the engine was introduced in the 1987 model year. The Supra was now related mechanically to the Toyota Soarer for the Japanese market.

    The new Mark III Supra engine, the 7M-GE, was the flagship engine of Toyota's arsenal. Both versions of the engine contained 4 valves per cylinder and dual overhead cams. The turbocharged 7M-GTE engine was Toyota's first distributor-less engine offered in the U.S which used coil packs sitting on the cam covers and a cam position sensor off of the exhaust camshaft[10]. It was equipped with a CT26 turbocharger and was rated at 230 hp (172 kW) at 5600 rpm while the naturally-aspirated 7M-GE engine was rated at 200 hp (149 kW) at 6000 rpm. Further refinement on the turbo model increased power to 232 hp (173 kW) and 254 lb·ft (344 N·m) in 1989. This was mostly due to a redesign of the wastegate.

    The naturally aspirated came as standard issue with the W58 manual transmission. The turbo versions included the more robust R154 manual transmission. Both were available with the optional 4-speed A340E automatic transmission.

    During the year of 1989, the car received new tail lights, a front bumper, steering wheel, lower redline (due to the heavier crank with cylinders 2 & 5 counterbalanced), badging and side trim amongst other features. Modifications to the wastegate actuator, feed location and engine management netted another 2 hp (1 kW) on the turbo model. The engine mount and brace were also changed so it could accommodate the 1JZ engine for Japan models. Fortunately, this also allowed the 2JZ engine to be put in since they both use the same engine mounts. The protective body molding was also changed by taking away the steel reinforcement. This made the molding lighter and prevented the rusting problem on the previous years. For the 1991 model year, the wheel design was changed to 5-spoke wheels. Both models wore 16x7 aluminum alloy wheels that were fitted with 225/50/16 tires and full-sized spares on steel wheels. It was also the last Supra to come with hood struts and a full-sized spare wheel since they added weight.

    The Supra was also available in two non-export models in Japan, the JZA70 with a 2.5 L 280 hp (209 kW) twin-turbo 1JZ-GTE, known as 2.5GT Twin Turbo (JZA70), and the GA70 with a 2.0 L 210 hp (157 kW) twin-turbo 1G-GTE and non turbo 1G-GEU .

    A special version of the 1JZ-GTE equipped JZA70, the 2.5 Twin Turbo R, had black/gray Recaro seats, a Torsen differential, additional braces to mount the diff, Bilstein suspension and uprated springs, Momo wheel and gear knob and matching interior trim. This was the fastest factory production version of the Mk3 Supra, running a mid 14 second 1/4 mile. This model had no ABS and was the lightest of all the MK3 supras.

    The third-generation Supra represented a great deal of new technology. In 1986, options available for the Supra included 4-channel ABS and TEMS (Toyota Electronically Modulated Suspension) which gave the driver 2 settings which affected the damper rates; a third was automatically activated at WOT, hard braking, and high speed maneuvering. HKS also made a "TEMS Controller" to hack the system and activate it on the fly, though the controllers are now nearly impossible to find.

    ACIS (Acoustic Controlled Induction System), a method of controlling air compression pulses inside the intake piping to increase power, was also apart of the 7M-GE's technological arsenal. All models were fitted with double wishbone suspensions front and rear. A targa top was offered along with a metal power sliding sunroof (added in '91).

    The 7M-GTE MA71's top speed is 156 mph (251 km/h). Due to an extremely restrictive exhaust, the 7M responds very well to exhaust modifications; often yielding 10 hp (7 kW) more by switching to a 'divorced downpipe' (where rather than blocking off an exit for the wastegated exhaust, it gives the gas its own pipe to flow through) and full 3" diameter exhaust.[citation needed]

    [edit] Turbo A

    The Turbo-A was Toyota's evolution model for Group A touring car championships all over the world which required a minimum of 500 which were only sold in Japan and was produced between August and September 1987. Some noted differences between the standard Supra and the Turbo-A model are both cosmetic and some mechanical. The front nose features the ducting to cool the engine, the badging 'turboA' and a Black paint job (all 500 are black). The engine bay features a 287 hp (214 kW) 7M-GTEU. All Turbo-As also came standard with leather interior.

    The car did not win as many races as hoped, being a 3.0 L it was forced to run with more weight where the R32 Skyline GTR didn't have the same restriction and was soon outmoded by the latter when it made its debut in 1990. For the JTCC Toyota would in 1991 switched to racing AE111 Corolla Levins in the lower category until the series final year in 1993. However in the less 'limited' racing it did considerably better.

    [edit] Quick info
    Mark III Quick information by Chassis code Code Year Engine Power Torque Transmission Market
    MA70 1986.5-1992 3 L (2954 cc, 180 cu in) 7M-GE I6 200 hp (149 kW) 196 lb·ft (266 N·m) 5-speed W58 manual
    4-speed A340E automatic CAN EUR USA
    3 L (2954 cc, 180 cu in) 7M-GTE turbo I6 230 hp (172 kW)/232 hp (173 kW) 240 lb·ft (325 N·m)/250 lb·ft (339 N·m) 5-speed R154 manual
    4-speed A340E automatic CAN EUR JPN
    MA71 1987-1992 3 L (2954 cc, 180 cu in) 7M-GTE turbo I6 230 hp (172 kW)/232 hp (173 kW) 240 lb·ft (325 N·m)/250 lb·ft (339 N·m) 5-speed R154 manual
    4-speed A340E automatic USA
    GA70 1986.5-1992 2 L (1988 cc, 121 cu in) 1G-GEU I6 160 hp (119 kW) 130 lb·ft (176 N·m) 5-speed W58 manual
    4-speed A340E automatic JPN
    2 L (1988 cc, 121 cu in) 1G-GTE turbo I6 205 hp (153 kW)/205 hp (153 kW) 180 lb·ft (244 N·m)/190 lb·ft (258 N·m) 5-speed W58 manual
    4-speed A340E automatic JPN
    JZA70 1990-1992 2.5 L (2491 cc, 152 cu in) 1JZ-GTE Twin Turbo I6 280 hp (209 kW) 268 lb·ft (363 N·m)-272 lb·ft (369 N·m) 5-speed R154 manual
    4-speed A340E automatic JPN

    [edit] Mark IV (1993-2002)
    Mark IV 1993-1995 Toyota Supra
    Also called Toyota Supra MK IV
    Production 1993–2002
    Assembly Motomachi, Japan[11]
    Platform JZA8x
    Engine(s) 3 L (2997 cc, 183 cu in) 2JZ-GE I6
    3 L (2997 cc, 183 cu in) 2JZ-GTE I6
    Transmission(s) 5-speed W58 manual

    6-speed V16x manual
    4-Speed A341E automatic
    Wheelbase 2550 mm (100.4 in)
    Length 4515 mm (177.8 in) (1993-1998)
    4514 mm (177.7 in) (1999-2002)
    Width 1811 mm (71.3 in)
    Height 1265 mm (49.8 in) (1993-1998)
    1275 mm (50.2 in) (1999-2002)
    Curb weight 1460 kg (3219 lb) (non-turbo)
    1581 kg (3486 lb) {turbo}
    Fuel capacity 70 litres (18.5 US gal)[2]
    1994 Supra with Targa top

    With the fourth generation of the Supra, Toyota took a big leap in the direction of a more serious high performance car. Test model pre-production started in December 1992 and official mass production began in April 1993.[12] The new Supra was completely redesigned, with rounded body styling and featured two new engines: a naturally aspirated 2JZ-GE producing 220 hp (160 kW; 220 PS) at 5800 rpm and 210 ft·lb (280 N·m) at 4800 rpm of torque and a twin turbocharged 2JZ-GTE making 280 hp (209 kW; 284 PS) and 318 ft·lb (431 N·m) of torque for the Japanese version. For the export model (America/Europe) Toyota upgraded the Supra turbo's engine (smaller, steel wheeled turbochargers, bigger fuel injectors, etc.). This increased the power output to 320 hp (240 kW; 320 PS) at 5600 rpm and 315 ft·lb (427 N·m) at 4000 rpm. The turbocharged variant could achieve 0–60 mph in as low as 4.6 seconds and 1/4 mile (402 m) in 13.1 seconds at 109 mph (175 km/h) [2]. The turbo version was tested to reach over 291 km/h (181 mph) all-stock, but the cars are restricted to just 180 km/h (112 mph) in Japan and 250 km/h (155 mph) elsewhere. European versions also had an air intake on the bonnet (hood). Drag coefficient is .31 for the naturally aspirated models and .32 for the turbo models and N/A's with the rear spoiler.

    The MKIV Supra's twin turbos operated in sequential mode instead of the more common parallel mode. The sequential setup featured a pair of CT-12b turbos (for the usdm market, JDM market was CT20/Ct20A with variations- some are ceramic- notorious, some are not. For UK and USDM market steel blades (CT-12b).

    Some differences in the OEM twin turbo JDM and USDM/UKDM JZA80 turbine setups include:

    JDM (CT20) has 3 bolt flanges for turbo to header. USDM/UKDM (CT12) is 4 bolt.
    JDM (CT20) has no pressure bypass X-over pipe, USDM/UKDM (CT12) does.
    JDM (CT20) has oval exhaust header to turbo ports and 3" downpipe, some are 2 bolt, some are 3 bolt.
    USDM/UKDM (CT12) has 4" downpipe outlet, and full bore round ports from exhaust header to turbo.

    Supposedly both setups are rebuildable from Garrett or other parts bin similarities with machining. Some rebuilds are better than others.

    Initially all of the exhaust is routed to the first turbine for reduced lag. This resulted in boost and enhanced torque as early as 1800 rpm. Approaching 3500 rpm, some of the exhaust is routed to the second turbine for a "pre-boost" mode, although none of the compressor output is used by the engine at this point. Approaching 4000 rpm, the second turbo's output is used to augment the first turbo's output. As opposed to the parallel mode, the sequential turbos provides quicker low RPM response and increased high RPM boost. The valve seal problem was back from the Mark II engines. Another weakness is the engine mounts.

    For this generation, the Supra received a new 6-speed Getrag/Toyota V160 gearbox on the Turbo models while the naturally aspirated models made do with a 5-speed manual W58, revised from the previous version. Both models were offered with a 4-speed automatic with a manumatic mode. However, the turbo model utilized larger 4-piston brake calipers on the front and 2-piston calipers for the rear. The base model used smaller 2-piston calipers for the front and a single piston caliper for the rear. The turbo models were fitted with 235/45/17 tires on the front and 255/40/17 tires for the rear. The base model used 225/50/16 for the front and 245/50/16 for the rears. All vehicles were equipped with 5-spoke aluminium alloy wheels and a "donut" spare tire on a steel wheel to save weight and space. Additionally, there are other differences in the rear axle differential, headlight assemblies, throttle body, oil cooler and a myriad of additional sensors that exist on the turbo model which do not exist on the normally aspirated model.

    Toyota took measures to reduce the weight of the current model compared to the previous model. Aluminium was used for the hood, targa top (if so equipped), front crossmember, oil and transmission pans, and the suspension upper A-arms. Other measures included dished out head bolts, hollow carpet fibers, magnesium steering wheel, plastic gas tank and lid, gas injected rear spoiler, and a single pipe exhaust. Despite having more features such as dual airbags, traction control, larger brakes, larger wheels, larger tires, and an additional turbo, the car was at least 200 lb (91 kg) lighter than its predecessor. The base model with a manual transmission had a curb weight of 3,210 lb (1,460 kg). The Sport Roof added 40 lb (18 kg) while the automatic transmission added 55 lb (25 kg). It had 51% of its weight up front and 49% to the rear wheels. The turbo model came in as 3,505 lb (1,590 kg) with the manual and the automatic added another 10 lb (4.5 kg). The front wheels held 53% of the weight and the rear wheels had 47% of the weight.

    For the 1996 model year in the U.S., the turbo model was only available with the automatic transmission due to OBD-II certification requirements. The targa roof was made standard on all turbo models. For 1997, the manual transmission returned for the optional engine along with a redesign of the tail lights, headlights, front fascia, chromed wheels, and other minor changes such as the radio and steering wheel designs. The SZ-R model was also updated with the introduction of a six-speed Getrag V161 transmission, the same used for the twin-turbo RZ models. All 1997 models included badges that said "Limited Edition 15th Anniversary." For 1998, the radio and steering wheel were redesigned once again. The naturally aspirated engine was enhanced with VVT-i which raised the output by 5 hp (4 kW; 5 PS) and 10 ft·lbf (14 N·m) of torque. The turbo model was not available in California, New Jersey, New York and Massachusetts due to increased emission regulations.[citation needed] In Japan, the turbo engines were installed with VVT-i as well.

    The stock MKIV Supra chassis has also proven an effective platform for roadracing, with several top 20 and top 10 One Lap Of America finishes in the SSGT1 class. The Supra is one of the heavier 2-door Japanese sports cars, however still lighter than the Skyline R33 GT-R, while only being slightly heavier than the R32 GT-R and the R34 GT-R (to which the Supra is traditionally a rival in its home country)[13][14][15]. The Supra was also lighter than the Mitsubishi 3000GT VR4 and the Nissan 300ZX Turbo. Despite its curb weight, in 1994 the MKIV managed a remarkable skidpad rating of 0.95 lateral g's (200ft) or 0.98 lateral g's (300ft) [1] due in part to a four-sensor four-channel track tuned ABS system with yaw control whereby each caliper is sensored and the brakes are controlled individually according to the speed, angle, and pitch of the approaching corner. This unique Formula One inspired braking system allowed the Supra Turbo to record a 70 mph (110 km/h) -0 braking distance of 149 feet (45 m) [2], the best braking performance of any production car tested in 1997 by Car and Driver magazine. This record was finally broken in 2004 by 3 feet (0.91 m) by a Porsche Carrera GT.

    Due to the strength of the stock non turbo engine, the 2JZ series 1994-1996 has remained a popular import platform for modification. The non-turbo cars were capable of going from 0-100 km/h in as few as 6.2 seconds and had 220 hp (160 kW; 220 PS) from the factory.

    Sales to Canada were ceased in 1997 (there were no 1996 Supras), and in the US in 1998. Production continued in Japan until August 2002, ceasing due to restrictive emission standards to be adhered to by 2003.

      Current date/time is Thu Mar 22, 2018 12:57 pm