Toyota once took turbines very seriously indeed. We look back at Aichi’s efforts.
Automotive technologies have a natural tendency to evolve. With Rover of Solihull firmly closing the door on gas turbines by the mid-1960s, we open an eastward-facing door, to see how Toyota took up the baton.
First mooted in 1965, sixty months of intense development took place at an undisclosed cost. The results brought forth a two-shaft gas turbine, intended for a bus chassis. A further five years of research entailed, the outcome being a car based turbine, the flagship Century being the chosen home for such a noble power unit. With its V8 removed, the gas turbine was not mechanically connected to the drivetrain. Instead, those ultra high revolutions charged a bank of batteries, in turn feeding motors to both front wheels – the gas turbine hybrid.
The Century tests were reasonably positive but Toyota’s engineers quite naturally wanted to improve matters further. For more, read less. Additional development reduced the system dimensions and weights with a grand reveal at the 1977 Tokyo motor show – the gas turbine powered, ridiculously cute and diminutive Sports 800 coupé.
As a production petrol powered pocket rocket, the Sports 800 coupé had harboured giant-killing performance with nimble handling and low weight, the elfin-like petrol producing 45bhp to shift 580Kgs. Plumbing in the single shaft turbine tipped the scales to the tonne, halved the number of forward gears and reduced power to 30bhp. Neither performance nor economy figures were revealed. Button cute the car might have been, but this pretty show had very little go.
Hybridisation maintained a germinating course within Aichi. With the 800 a production un-reality, the eighteen years of constant research and development came to close as their plans diverged. Smaller turbines were deemed more suitable for public transport applications, while petrol hybrid powertrains would gain impetus from good old fashioned internal combustion.
One further turbine spin arrived however in the form of the 1987 GTV (Gas Turbine Vehicle), based on the platform of the contemporary Soarer coupé model. Toyota engineer, Masumi Iwai had headed those initial mid-60s forays into turbine propulsion. Twenty years later, as Chief Project Engineer for Research and Development, Iwai, a genial chain smoker was determined for the concept to succeed, almost regardless of time and cost. The car itself was close to the 6-Series BMW in size, yet was more elfin in weight, and slipperier in coefficients.
GTV was a fully operational and road legal (in Japan) concept with rear wheel drive, speed sensitive power steering, along with all-round independent double wishbones suspended by air springs. ABS remained whereas the donor car’s AWD and AWS was omitted. Good for 125mph, the car idled at 10,000 rpm. A dashboard mounted button worked the handbrake, the dash containing two sources of amazement for Car’s Georg Kacher. The first was a rear-view video camera feed to a small, square tv screen (“most distracting but crystal clear”), alongside the turbine’s separate counter of revolutions which peaked at 53,000 though appeared to reach almost 70,000 rpm at V-Max.
Regenerating waste heat to increase efficiency, GTV differed from previous incarnations by incorporating one turbine to drive the compressor, the second being drive shaft connected. A two stage heat exchanger lowered exhaust gas temperatures to a rated 1050° C. Iwai observed that significant improvements could be had “at 1350,” but this required greater usage of ceramics, with added cost. Iwai’s team were impressed by the turbine’s reliability too, with one of their prototypes having reached 38,000 miles without requiring anything beyond normal servicing.
Nevertheless, he was also acutely aware of the car’s shortcomings. Firstly, the engine’s weight, a stout 440 lbs. Compare that to a contemporary Celica’s 330 lbs mill, swiftly followed by poorer fuel economy to the tune of 20-30% to that of a reciprocating equivalent. Even with instant torque, turbine lag made for kangaroo style progress at city driving speeds, hardly conducive to a Toyota’s normal easy going, slick image. The meatiest problem encountered however was that of torque and its affects upon the automatic transmission fitted to early prototypes, the turbine producing more turning effort than the converter could initially cope with. Shaft speeds were reduced and a softening of the gearbox’s characteristics slowly but surely began to yield results.
While overall, Car found in the GTV’s favour, turbine lag rather spoiled Kacher’s review of this competent and indulgent coupé, a matter readily acknowledged by Toyota’s Mister Turbine. Iwai informed his interrogator that it would take “ten to fifteen years” (from mid-1988) in order to see a viable production creation – the new millennium.
Replacing these turbines with a petrol engine led to a car born from those patient years of trial and error – the Prius, whose silky CVT gearbox would be honed in the GTV – and the only item from the 1987 prototype to make it to series production.
But does the gas turbine have any future now in an automotive application? While the amount of research, time and financial investment remain incontrovertible, there is no getting away from the fact that electric motors and batteries drive the current momentum. Perhaps in this battery EV free-for-all, Toyota have despaired of ever seeing the project take flight. But akin to Hollywood, the car industry loves a sequel, so never say never.
 The fuel (of whatever form chosen) which produced the power was converted into electrical energy by the generator. Fixed direct current (DC) entered the chopper or Electricity Control Unit, creating variable direct current to both boot mounted battery and wheels.
 At the close of that 22nd motor show, Toyota quietly tucked away the tiny turbine prototype until the 2009 motor show. Whether nostalgia brought it back into the public domain is unclear but the car had somehow grown an ugly and large bonnet scoop along with alloy wheels and a black roof. Your author could find no information regarding underbody changes.
 “Management have not questioned cost. When that happens, the final countdown has begun.”
 “Drive fast, the car is best at speed” – Iwai.
 Featured in the August 1988 issue of Car magazine.
 The original auto-box had originated in a Toyota Crown. A manual gearbox was tried very briefly but soon rejected.
Sources: classiccars.fandom/ Wonkypedia/ Road & Track/ Car Magazine.