The new Mark III Supra engine, the Toyota 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 US which used coil packs sitting on the cam covers and a cam position sensor driven by the exhaust camshaft. 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. All models used the same tire size of 225/50R16 on 16x7 inch wheels. Spare tires were full-sized but on steel wheels.
Owing to a large error in the factory head bolt torque specifications (likely owing to switching away from using an asbestos head gasket in lieu of a copper one), all of these engines had severe problems with blown head gaskets. Toyota never issued a recall for any of the affected vehicles. The problem could be easily fixed by replacing the head gasket and torquing the head bolts to 75 lb·ft (102 N·m) of torque. However, owing to the lack of a recall or appropriate service bulletin, the head gasket problem would recur in another 75,000 miles or so if the gasket was replaced and the bolts were retorqued to the erroneous service manual specifications of 56 lb·ft (76 N·m). With the head bolts torqued correctly, the engines were otherwise extremely durable.
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.
The third-generation Supra represented a great deal of new technology. In 1986, options available for the Supra included 3-channel ABS and TEMS 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 a part of the 7M-GE's technological arsenal. All models were fitted with double wishbone suspension front and rear. A targa top was offered along with a metal power sliding sunroof (added in '91).
Total Supra MkIII's produced: 108,565
1986
The third generation Supra was introduced in May 1986 as a free standing model, officially separating it from the Celica. Whereas the Celica became a front-wheel-drive sport coupe, the Supra retained its image as a rear-wheel-drive sports/GT car. The new Supra would continue to move upscale and become a showcase for Toyota technology. Originally meant to be released in 1985, production delays caused the model to actually be introduced mid year. The all new Supra was powered by a 3.0-liter DOHC inline six-cylinder engine rated at 200 bhp. Notable features included an electronically controlled independent suspension (called the Toyota Electronic Modulated Suspension – TEMS), and a removable Sport-Roof panel (Targa top).
Production: 33,283
1987
The first Supra Turbo was introduced in 1987. The inter-cooled, turbo charged version of the 3.0-liter inline 6-cylinder engine boosted power to 230 hp (172 kW; 233 PS) 240 lb·ft (325 N·m). The Turbo model also included an engine oil cooler and integrated rear spoiler. The sports package, which was standard on the Turbo and optional on the base model, included a limited slip differential (LSD), TEMS, and headlamp washers. A new Anti-Lock Braking System (ABS) was optional on both models. Also in 87 a new beige/tan color combination was implemented, and only 1000 models were produced with this scheme.
Production: 29,907
1988
Not much changed for the 1988 year, with the exception of the dropping of two-toned brown exterior paint. The turbo spoiler brake light changed from a square, to a trapezoid shape. Seat pattern was changed from squares to lines, and "foil" on climate control and switch gear changed from light to dark gray.
Production: 19,596
1989
During the year of 1989, 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 in late 1989, with the exact date not known as of this writing. The changes made to the cross member and mounts made to accommodate the 1JZ engine for Japan models. 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. The "white package" was introduced as well, featuring white body molding and white wheels. Interior choices were limited to blue and burgundy only. Other than pure cosmetics, there was nothing different from other models. All models received rear 3 point seat belts to replace the previous years' two point lap belts. New tail lights, front bumper with integrated lower grille (as opposed to the previous years' detachable grille), side mirrors, turn signals, upper grilles, foglights, steering wheel, door panels, climate control, window switches and bezels, and stereo. Addition of coat hooks on B-pillar and removal of rear seat pockets round out interior changes. Turbo models received three piece spoiler with integrated LED brake light. 1989 also marked the end of headlight washers in the U.S. and SuperMonitor; an advanced system offered by Toyota able to calculate miles able to be traveled on current tank, ability to check vehicle codes from inside the cabin, among other features.
Production: 14,544
1990
For the 1990 model year, changes included larger protective laminate in front of rear wheels, lower redline (owing to the heavier crank with cylinders 2 & 5 counterbalanced), redesigned steering wheel with cruise control relocated to a stalk on the right side. In addition to an airbag and airbag indicator light on dash, there was also a redesign of the left side switch panel, which replaced one of the coin slots with the dimmer. Lower dash panel became a two piece design, which was also much heavier than the previous one piece panel owing to a change in material. Finally the memory lever on the steering column was removed.
Production: 6,419
1991
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. Body molding changed in color to better match the exterior. The front "Supra" emblem was also changed to the current corporate oval Toyota symbol. The speedometer was also revised, and included more lines in the speedometer, that were removed in 1989, but still did not have as many (one line per mph) as 86.5 to 1988 models. New interior colors shadow gray and deep red were introduced, which marked the end of medium gray, tan and burgundy. Blue became only available on white packages, and those with blue paint. Burgundy was replaced with white package-only deep red. Every other body color received shadow gray, with leather interiors retaining medium gray seats and interior inserts. Front speakers were changed from 3.5" to 6.5" and the speaker cover was also enlarged to accommodate them.
Production: 3,623
1992
For 1992 leather shadow gray interiors received black seats and inserts. Non-turbo models lost the option of a targa top, and a new optional subwoofer was available. Subwoofer-equipped Supras did without the rear bins, and wooden "floorboard." Instead rear carpet was molded to the spare tire, and there was a cut-out for the woofer housing.
Production: 1,193
JZA70 and GA70
The Supra was also available in two non-export models in Japan, the JZA70 with a 2.5 L 280 PS (206 kW) twin-turbo 1JZ-GTE, known as 2.5GT Twin Turbo (JZA70), and the GA70 with a 2.0 L 210 PS (154 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 a Torsen differential, Bilstein suspension, larger diameter sway bars, Recaro seats, Momo wheel and gear knob and matching interior trim. The front lip included front brake ducts. The Twin Turbo R introduced the color option Metallic Dark Green.
Turbo A
The Turbo-A was Toyota's evolution model for Group A Japanese Touring Car Championships (JTCC) all over the world which required a minimum homologation run of 500 units which were only sold in Japan and was produced between August and September 1988. Thus the term 88 Spec A. Some noted differences between the standard Supra 3.0 GT and the Turbo-A model are both cosmetic and some mechanical. The engine came with a special head that had less valve shrouding, and clearance cut for higher lift cams. TRD sourced cams helped increase valve lift and the stock CT-26 turbo had a slightly larger inducer. The intercooler had extra rows of cooling tubes and the intercooler piping was larger in diameter. The turbo-A had a 65mm throttle body, instead of the standard 7M-GTE 60&mm size.
The fuel management used a MAP system, instead of the standard Karmen Vortex AFM and is a popular and easy swop-out for stand-alone management systems. The front bumper and the 3-piece spoiler and taillights were used on all Japanese market and US market cars. European market vehicles starting in 1989 instead of the typical 86–88 set, were sold in a stealthy plain white, without decals or the 3-piece tailgate spoiler. The front nose however features an additional "Turbo A duct" to add airflow to the heat exchangers. Also unique was the side decal and rear badging ("3.0GT Turbo A") and a black paint job (paint code 202) on Japanese and US market cars. All Japanese Turbo-As came standard with grey leather interior featuring a Momo-sourced steering wheel and shift knob. European models have velour, once again rendering them incognito among the lesser 3.0GT models. Its engine bay features a 266 hp (198 kW) 7M-GTEU.
The car did not win as many races as hoped as it was bumped up a class due to engine size. Being a 3.0L, it was forced to run with more weight whereas the equally powerful, higher revving but slightly smaller capacity R32 Skyline GTR did not have the same weight restriction. It was soon outperformed by the Skyline GT-R R32 when it made its debut in 1990. For the Japanese Touring Car Championship (JTCC), Toyota would in 1991 switch to racing the Corolla Levins instead in the lower category until the series final year in 1993. However in the less 'limited' racing, like Group B Rally Championships, National Drag racing, Hill climbs, Sprint Events and Clubmans series, the Supra Turbo-A did considerably better.
All Turbo-A cars were fitted with a TRD-sourced torque-vectoring mechanical limited-slip differential with 50:50 left:right lockup on full throttle. TRD was also responsible for the thick rear-anti squat tram-rods which was integral to the multi-link rear suspension setup to control rear squat under hard acceleration and launching.
No comments:
Post a Comment