1968 Lotus Elan Sprint
In 1962, Lotus announced the Elan to take over from the Elite. This was an entirely different type of chassis, designed specifically with series production in mind, for it could be stripped out and repaired more easily. The designer was persuaded of the advantages of having a separate chassis, particularly in an open car. From this the simple, but very rigid, folded steel backbone frame was conceived.
It was agreed that the body could be made only in two parts – a top and a bottom. This type of construction has been used on all other Lotus road cars put on sale since.
Sixteen mounting points were provided for the body, which was made up of laminations of fibreglass, mostly 31.8 mm thick, increasing to 63.5 mm at major stress points. These included the chassis mountings, where bobbins were bonded in to accept securing bolts. Very wide doors, which were hung on nylon pegs, were fitted to make access easier. Problems associated with mounting the bonnet were overcome by replacing hinges with an ingenious self-balancing system that used swivels and allowed the bonnet to be taken off as a complete unit. The boot lid used conventional exterior hinges as it was lighter.
The seats also presented a problem; there was not enough room for the Elite seats, which were rather expensive to make, so a more simple design using snake wire springs was devised. They were fitted with fixed backrests mounted on inclined ramps, allowing for a wide range of driving positions.
A twin-overhead cam coversion of the four-cylinder Ford engine, first as a 1499 cc, then as a 1558 cc unit, was designed by Harry Mundy. This unit was later used in the Lotus Cortina, and several other Lotus models. Independent front suspension was by upper and lower wishbones, with a combined coil spring/damper unit, all allied to rack and pinion steering. At the rear there was a MacPherson strut.
Disc brakes were fitted all round, and since those at the rear were outboard and there were rubber drive shaft `doughnuts’ in the system, this soon gave the Elan a reputation for transmission wind-up. Also the doughnuts always had a limited life.
When the Elan Sprint was launched in a great blaze of publicity, it was claimed that it would take only 6.2 seconds to reach 96km/h from rest – faster, for instance, than a Lamborghini Miura or a Jaguar E type.
First road tests of a Sprint noted that the engine had lost none of its tractability and said that it was considered the Elan Sprint was probably one of the fastest ways of getting from A to B. Evaluations of the Elan Sprint found that a car fitted with a Stromberg carburettor was a good deal slower than one fitted with the British Weber version.
The Weber fitted Elan was the fastest tested, and with its other qualities, made it the best. The only real complaint was that the new exhaust system was too quiet: the old rude rasp was too much, but this was too little.
