Interim report on the Lotus Elite
The Lotus Elite coupé was the sensation of the last Earls Court Motor Show and gave a merciful boost to British prestige at an Exhibition in which the majority of our cars rose very little above the mediocre.
With independent suspension all round, a glass-reinforced plastic chassis/body shell with a minimum of metal bonded in, disc brakes, inboard at the rear, and an o.h.c. engine giving 75 b.h.p. in a two-seater coupé weighing under 11 cwt., the Lotus Elite has caught the imagination of enthusiasts and should be Britain’s answer to Continental Gran Turismo cars. The sort of car this Lotus is intended to be is indicated by a cryptic note in the catalogue which States: “There is room for two spare wheels; it is not possible for a third person or children to be carried in the car”—a courageous announcement on the part of Colin Chapman, Lotus chief, who is a family man with two daughters (the second born on January 10th)!
Although the Lotus Engineering Co. Ltd., of Hornsey, got the prototype Elite to Earls Court last October by a prodigious effort, Chapman wisely stated that production would not commence until he was completely satisfied with the car.
However, this is such an interesting little motor car that I went along last month to secure an interim report on it. The idea of building the Elite dates back to Christmas 1956, when Chapman decided he wanted to build a Lotus for which there would be a greater demand than exists for open sports/racing cars, and one able to compete in events for G.T.-type cars. He was keen to have a glass-fibre body, for ease of production and because an engine giving a decent power output would be excessively noisy in a steel-shrouded space-frame. The new epoxide resins, having twice the strength of polyester resin, suggested that it should be possible to dispense with a separate metal frame, this development in glass-fibre technique being used by the Aircraft Industry: for example. for the wing of the D.H. Comet.
A full-scale plaster-of-Paris model was made and shown to the glass-fibre experts, but results were far from satisfactory with the resins and fibres originally suggested. It is typical of Colin Chapman that he refused to give up. Instead he consulted people at De Havillands, who were extremely helpful. It became apparent that a glass-reinforced plastic monocoque structure could be stressed and employed as the chassis.
A year after the Elite project had commenced three Ford apprentices asked if they could visit the Lotus factory. What they saw impressed them and in this way John Frayling joined Chapman. Together they took a course in plastics in Wolverhampton, and Frayling, who is Production Manager on the Elite project, set about making clay models, helped by Peter Kirwan-Taylor. who had already built special bodies on Lotus and Doretti chassis. In this way the styling of the proposed low, compact, clean G.T. coupé evolved and Frayling made a ⅕-scale model of the finalised design, to which Frank Costin gave a clean bill of health aerodynamically.
All this occupied these idealists for some three months of evening toil. Just before Chapman left for Sebring last April, the design was approved and Ian Jones, from Vandervell, started to prepare production drawings.
After the Motor Show Chapman set about revising the prototype. Very few modifications were deemed necessary, but the production Lotus Elite will have proper double draught-seals for the doors in place of the rather casual sealing on the prototype, this being quite a major re-design task, provision was made for left- or right-hand steering, and Colin resolved to use i.r.s. and not use a beam rear axle as an alternative. This last-named decision was based on the wide payload variation unavoidable in a light economical G.T. car, in which 50 per cent. of the weight has to be carried by the back wheels to provide sufficient adhesion. Too-stiff springs give a very uncomfortable ride and soft springs result in loss of stability consequent on uncontrollable changes from over- to understeer. What Chapman wanted were suspension units which would provide the required camber changes under local variations. Consequently he devised the strut-type coil-spring units for the Elite. These were used on the new Lotus F. II racing cars, and proved thoroughly successful, although the problem here was formidable, because a front-engined F. II car needs 60 per cent. of its weight on the rear wheels and with a de Dion back axle the car oversteers seriously with a full fuel load but understeers when light. Chapman’s simple i.r.s., using the strut-units, overcame this, camber changes counteracting changes in weight. Incidentally, the suspension pick-up points are common to the whole range of Lotus models.
The decision to use F. II i.r.s. necessitated stiffening the rear end of the Elite body/chassis structure, and it then proved practicable to move the toolbox and battery from the boot, thus providing greater luggage stowage behind the bulkhead, in front of which the spare wheel is mounted horizontally.
To date the Elite has not been fully road-tested but rig tests to check torsional strength, and tests on the bonding of brackets and other metal attachments, have been carried out.
It is again typical of Chapman’s approach to a new project that he acquired a small factory in Edmonton, where experimental work on the Elite has been quietly conducted. This will eventually become the assembly shop, complete body shells being made by outside contracts and delivered there for the attachment of suspension units, installation of engine, etc. Glass matt will be supplied by the Turner Asbestos Co., a branch of the Ferodo organisation. Special seats have been evolved in conjunction with Dunlop, of foam-rubber rolls over laths, with quickly-adjustable squabs, somewhat on Porsche lines but much shallower, for the Elite is a low car, only 3 ft. 10 in. high. So that 9½-in. Girling disc brakes can be used all round, Lotus will make the calipers for the rear brakes, which are not otherwise obtainable. Brake cooling will be assured by the use of centre-lock wire wheels.
Lucas will supply special Le Mans headlamps with integral side-lamps. The fuel tanks are ingenious. They consist of boxes which are present in the front wing structure. These are bonded and automatically leak-proof but are sprayed internally with rubber, then constituting integral, very satisfactory, petrol tanks. Normally one will be provided, of eight gallons capacity, but, if required, two can be used, when the range is likely to be 640 miles!
Chapman is determined that the Elite will be a docile, tractable as well as a very fast car. With this in mind he uses a detuned 1,290-c.c. Coventry-Climax engine rather than a high-output 1,100-c.c. unit. For the same reason a single 1½-in. S.U. carburetter is specified, but, even so, 75 b.h.p. is developed by this FWE engine at 6,100 r.p.m. The gearbox is M.G.-A.
Another problem was that of tyres and it is pleasing to be able to report that Firestone, who made the special racing tyres for Monza track circuit last year, are going to supply special nylon-carcase covers with their new P300 tread for the Elite. These 15-in. tyres (Colin does not like tiny wheels) are correct weight for the 3½ cwt. each carries. Other makers could only offer 4.90 by 15 tyres capable of carrying up to 6½ cwt., which were too heavy for Chapman’s purpose.
The Lotus Elite uses ducted cooling but if boiling occurs in traffic an electric fan will probably be added.
Moulds of double and half the thickness of the production Elite bodyshell have been made experimentally, but a thickness of approximately ⅛ in. has been decided upon, the only major steel reinforcement being a tubular hoop bonded in at the front of the roof, the base extremities of which constitute the car’s jacking points.
Although no attempt has been made to venture into realms of extreme lightweight construction, the Elite hull weighs only 200 lb., or a mere 10 lb. more than the 1,100-c.c. Lotus space-frame chassis/body unit complete with brackets, although naturally this increases when Triplex laminated safety-glass has been fitted. Even so, a spartan version of the Elite should riot weigh more than the 1,100-c.c. sports Lotus. Chapman quotes 10/10½ cwt. fully equipped and suggests that with a 4.5-to-1 axle ratio speed will be 110/115 m.p.h. in untuned 40-m.p.g. form. Eight axle ratios will he available. A paint finish will be sprayed on to improve the already self-coloured finish.
The Lotus Elite is the most promising British G.T. car of the present decade and we await a road test with impatience. We are able to announce that production will commence on April 1st. Output will be three a week for three months, increasing thereafter to ten a week. Sensibly, no Lotus Elites will be exported until 100 have been sold on the home market. Chapman hopes to hold the price to £1,950, and distribution will be in the hands of the Alexander Engineering Co., Michael Christie thus having the headaches of supplying special equipment to individual requirements. It is hoped that the first production model will be at the Geneva Show, which opens on March 13th. It is about time you sent your orders in, thereby supporting a very honest and ambitious attempt to put Britain in the forefront of G.T.-car construction-and perhaps, indirectly, assisting Lotus to field a team of F. I Grand Prix racers. — W. B.