Toyota Celica TwinCam Turbo (Group B)

Published on: Jan 21, 2016 @ 15:01
Originally Published in: 2014 (old website)
(C) Jay Auger - website owner & author
Notice: Any form of duplication methods (including but not limited to copy/paste of text and screen capture) of the website's content is strictly forbidden.
Toyota Celica TCT TA64 – Safari

INTRODUCTION

Similar to its Japanese cousin, the Nissan 240RS, this rear wheel drive competitor was conceived and built with the traditional “Group 4” way of designing rally cars that reigned over international rallying before the arrival of Group B in 1982. This “lack of vision” by the Toyota Team Europe (TTE) engineers obviously led the Celica Twin Cam Turbo (TCT) soon being dominated by the four wheel drive supercars in the World Rally Championship. However, the Celica had a few aces up its sleeve that would see it beat the supercars in specific events.


QUICK BROWSE CONTENT


HISTORY

Traditional automotive engineering does have its perks when it comes to rallying; using a standard production model offers ruggedness and reliability, both of which are key to winning endurance events, and both of which were somewhat lacking with the bespoke Group B supercars.

Furthermore, compared to the Nissan 240RS, the Celica TCT had a turbocharged engine, and a very powerful one at that: the 2090 cc 4T-GTE powerplant could produce up to 380 BHP. However, all of that power remained driven only through the rear wheels, which made the car more difficult to drive on slippery terrain.

While the Celica TCT had a hard time competing in the WRC stage rallies, it did however excel at its endurance events; winning three Rallye Côte d’Ivoire and three Safari Rally events from 1983~1986 in the capable hands of legendary drivers such as Björn Waldegård, Per Eklund, and Juha Kankkunen. It dominated so convincingly that the Celica received the nickname “The King of Africa”.

The Celica was so proficient in this niche that the Toyota engineers didn’t dare produce another evolution of the car in its entire 4-year participation in Group B rallying, less some very minor braking system upgrades in 1986.

Ultimately, albeit it could not compete directly against its superior four wheel drive competitors in special stage format, the Celica TCT is nonetheless arguably considered as one of the most successful rear wheel drive cars of the Group B era. Only the purpose built mid-engine Lancia 037 can claim to have done better overall.

For 1987, the Celica TwinCam was planned to be replaced by the MR2 (222D) supercar as Toyota’s weapon of choice in the WRC but the project was cancelled alongside Group B/S’ demise. However, its legacy would carry on with the now legendary Group A Celica GT-Four / All-Trac version.


RALLY CAR SPECIFICATIONS

Group/Class B/12 Homologation number: B-239 (click to see papers)
Years active 1983~1986 Homologation

  • start: August 1st 1983
  • end: December 31st 1988
Engine
Type 4T-GTE, I-4, DOHC 16v, gas located front longitudinal with 4o left inclination
Displacement 2090 cc WRC x 1.4 = 2926 cc
Compression ratio 7.1:1 ~ 8.0:1
Output power – torque 330~380 HP @ 7500~9000 rpm 250~320 lb-ft (343~430 Nm) @ 5500 rpm
Materials block: cast iron cylinder head: aluminium alloy
Aspiration
  • KKK K27 turbocharger
  • air/air intercooler
  • Nippon Denso D-jetronic multipoint EFI
boost: 8~13 psi (0.55 ~0.90 bar)
Ignition electronic,  Nippon Denso, 2 spark plugs per cylinder, firing order 1-3-4-2
Cooling system water-cooled
Lubrication system dry sump 15 lt
Transmission
Type rear wheel drive 5 speed hewland gearbox
Gearbox ratios constant: 1.364
1st: 2.818
2nd: 1.860
3rd: 1.423
4th: 1.169
5th: 1.000
R: 4.196
constant: 1.364
1st: 2.273
2nd: 1.719
3rd: 1.364
4th: 1.145
5th: 1.000
R: 4.196
Differential ratios 5.374, 4.889, 4.545 hypoid bevel gears limited slip rear differential
Clutch dry, double plate
Chassis-body
Type steel monocoque TA64 chassis with roll cage and front steel subframe. 2 door coupe steel bodyshell with plastic front and rear bonnets, plastic doors, plastic bumpers and plastic rear spoiler
Front suspension mc pherson strut with lower L wishbone, coil spring, telescopic gas shock absorber and anti-roll bar 15 to 30mm diameter
Rear suspension live axle with 2 lower radius arms, 2 upper 45olocation arms, parhar rod, coil springs, telescopic gas shock absorber and anti roll bar 10 to 20mm diameter
Steering system rack and pinion 2.25 turns lock to lock (13:1)
Brakes
  • F: ventilated rotors 260/285mm diameter 4 aluminium piston calipers.
  • R: ventilated rotors 264/285mm diameter with 2/4 aluminium piston calipers.
  • 1986+: front ventilated rotors 300mm diameter
dual circuit with servo, adjustable ratio split front to rear
Dimensions
length: 4284 mm (168.7 in) width: 1785 mm (70.3 in) height: 1410 mm (55.5 in)
wheelbase: 2500 mm (98.4 in) front track: 1410 m (55.5 in) rear track: 1400 m (55.1 in)
Rims – tires
  • Speedline light alloy
  • front: 6″ – 8″ x 15″
  • back: 7″ – 10″ x 15″
  • Pirelli
  • front: 185~215 R15
Dry/Unladen Weight 1020~1100 kg (2250~2425 lb)
Weight/power 3.0 kg/HP (6.6 lb/HP)
Fuel tank 100 lt (130 lt for Safari)

HOMOLOGATION VERSION

Toyota Celica GT-TS

In 1982, the Celica was a mainstream production model which had many variants. However, Toyota decided to base its Group B homologation requirements on the then top of the line GT-T model (TA63) and produced the GT-TS (TA64) in limited numbers. The use of a separate and unique identifier was expressly done for the option to perform an “evolution” (ET) model for racing without having to stop production of the regular Celica (as the Group B regulations demanded in such a situation).

The GT-TS was not a turn-key rally car, unlike some of its bespoke Group B homologation supercar counterparts, as the “evolution” rally cars themselves had extensive modifications done to the chassis, suspension, and engine. As such, it would have been rather difficult and very costly for a privateer to modify a normal Celica in this way.

The Toyota Celica GT-TS was nonetheless a capable sports car for the road with its 180 BHP turbocharged engine, but as opposed to the rally version it fell short of its Nissan 240RS rival in homologation form.

225 right-hand drive homologation cars were reportedly produced in 1982, 25 of which were converted to left-hand drive and turned into evolution models specifically for international rally competition and for the WRC, making the special GT-TS version of the Celica very rare and coveted amongst the Japanese and Group B collector crowd.


ROAD CAR SPECIFICATIONS

Class compact Homologation number: B-239 (click to see papers)
Production 1982

  • 200 homologation models
  • 25 evolution models (TTE)
Assembly: Japan
Engine
Type 4T-GTEU, I-4, DOHC 16v, gas located front longitudinal with 4o left inclination
Displacement 1791 cc
Compression ratio N/A
Output power – torque 180 HP @ – rpm N/A – lb-ft @ – rpm
Materials block: cast iron cylinder head: aluminium alloy
Aspiration
  • CT20 turbo
boost: N/A
Ignition electronic, Nippon Denso, 2 spark plugs per cylinder, firing order 1-3-4-2
Cooling system water-cooled
Lubrication system N/A N/A
Transmission
Type rear wheel drive 5 speed W55 gearbox
Gearbox ratios N/A N/A
Differential ratios 4.100 F-series limited slip rear differential
Clutch N/A
Chassis-body
Type steel monocoque TA64 chassis and front steel subframe. 2 door coupe steel bodyshell with plastic front and rear bonnets, plastic bumpers
Front suspension mc pherson strut with lower L wishbone, coil spring, and anti-roll bar
Rear suspension live axle with 2 lower radius arms, 2 upper 45location arms, parhar rod, coil springs, and anti roll bar
Steering system rack and pinion 19:1 ratio
Brakes N/A N/A
Dimensions
length: 4435 mm (174.6 in) width: 1665 mm (65.6 in) height: 1310 mm (52.0 in)
wheelbase: 2500 mm (98.4 in) front track: N/A rear track: N/A
Rims – tires
  • N/A
  • N/A
Curb Weight 1060 kg  (2340 lb)
Weight/power 5.9 kg/HP (13 lb/HP)
Fuel tank N/A

VIDEOS


REFERENCES

 Affiliates Program – (free delivery worldwide!)

 Group B – The rise and fall of rallying’s wildest cars

Group 4 Group 4 – From Stratos to quattro

Safari Safari Rally: 50 Years of the Toughest Rally in the World

  • Any purchase you make through the Affiliates program helps support the Shrine!

(C) Article by Jay Auger – website owner & author

  • Images & videos are the property of their original owners
  • All homologation papers are the property of the Fédération Internationale de l’Automobile (FIA): SOURCE
  • DISCLAIMER / LEGAL NOTICES
Advertisements

WELCOME TO THE ENCYCLOPEDIA OF THE GOLDEN ERA OF RALLYING

Advertisements