Autocar added: “Thus Lotus have to put up with the weight of four-wheel drive and an excessive fuel load in exchange for an engine which weighs half as much as the DFV and develops up to 500bhp at 45,000rpm.”
No gearbox or clutch were required, either. In comparison, the Tyrrell’s DFV was kicking out around 450bhp at just 10,800rpm.
“The 56B has a Ferguson apportioning centre differential driven from the turbine output shaft by a Morse Hy-Vo chain,” we continued.
“The drive from the centre differential is transmitted fore and aft along the left-hand side of the car by small-diameter solid drive shafts encased in guard tubes. The front and rear Lotus ZF locking differentials are developed versions of those used on the four-wheel-drive Cosworth-powered Formula 1 car and are housed in box extensions of the monocoque which, in this car, extends the full length to act as a cradle for the turbine aft of the car.
“Brakes are inboard with short solid drive shafts with GKN constant velocity joints to the wheels. In view of the extra load on the brakes in a turbine car, they have 10.5in-diameter ventilated discs with a good flow of air to the middle of the disc and extractors in the top panel of the nose.”
Gas turbines do not produce engine braking, so these enlarged units were vital. Still, they often overheated, with driver John Miles very lucky not to have been injured when they failed at Lotus’s Hethel test track.
“The chassis side sponsons are two simple boxes joined by the floor and by diaphragms front, rear and amidships. They hold the rupture-proof fuel bags containing 62 gallons of kerosene,” we wrote.
This was only enough for 160 miles – not a full grand prix distance. Therefore, we said, “the 56B will either have to be fast enough to gain enough time for a fuelling stop, be given bigger tanks or have its consumption improved if it is to be competitive with piston-engined cars.” Unfortunately, this issue was never resolved.
We continued: “Designed as a helicopter engine, the STN 6/76 two-shaft axial flow engine has been modified for this Formula 1 application. This has involved reducing the area of the combustion chamber nozzle, which feeds hot gas to the turbines, while two of the three stages of the axial-flow compressor have been removed.