The Classic Team Lotus Festival, Snetterton 19/20 June

Our next Championship Rounds, at Snetterton on 19/20 June are part of a major feature meeting being promoted by our co-organisers Motor Sports Vision Racing – The Classic Team Lotus Festival, which is to be held on Sunday 20 June. In recognition of ‘The Classic Team Lotus Festival’, the editor has had a few thoughts about some Loti.

“You see? It designs itself”, Anthony Colin Bruce Chapman.

As a biologist I am an evolutionist who finds greatest interest in the products produced in a period of transition. There are some remarkable animals and plants around these days, who would believe the octopus, squid or starfish, but when confronted with body plans that occur in the Burgess Shale, one stands back in amazement. Colin Chapman had the ability to think 'outside the box', in an era when designers of F1 cars were less limited by regulations than they are now. He advanced the evolution of the GP car by reconfiguring the basic design in ways that others had not imagined.

Lotus 16 (1958-1959)

Era. Towards the end of the 2.5 litre formula. Minimum race distance had been cut from 300 to 200km, fuel was specified as Avgas instead of an explosive and corrosive brew frequently containing nitro methane. The result was that the 2.5 litre GP cars shrank in size, F2 machinery being upgraded to F1. However, the championship in 1958 was won by the last of the large dinosaurs, the Vanwall.
Description. I have included the Lotus 16 because it is front engined. I Iike its appearance and Chapman's ambition, but why he took the front engined route is a mystery. Very tightly packaged, at least it did not look out of place on a GP grid, unlike the 12, its spidery predecessor.
Achille's heel(s). The Coventry Climax engine was not that keen about being installed canted over, the offset drive line caused power losses, gearboxes were weak and everything cracked or fell off. Running a successful GP campaign was beyond the capabilities of Team Lotus at this time. Suitably strengthened, and properly prepared, these cars now run successfully in historic racing.

Lotus 18 (1960)

Era. The success of the Cooper Climax in 1959 had made front engined GP cars obsolete. The Climax engine, the engine of choice for the small British chassis builders, had been progressively enlarged to 2.5 litre capacity, the resultant torque made most gearboxes marginal. Like our Hewland Mk9 boxes, GP gearboxes were usually built into casings designed for other purposes. Coopers did the job properly, and their expensive and reliable units served them well, when transmission failure was a frequent cause of retirement, they won the championship.
Description. The 18 can claim to be the first rear engined car with a proper small diameter tube space frame. Mercedes (W196) and Lotus had used aircraft style space frames from 1954 for their front engined cars, but most manufacturers employed large diameter curved tubes (like an Ariel Atom). The 18 was very light and simple, but why, after producing the elegant 16, Chapman chose to style the 18 after a house brick is inexplicable.
Achilles Heel(s). Probably the fastest cars of their era, 18s rapidly gained a reputation for fragility, bits fell off them; important bits like wheels. The brakes were also prone to failure, the winning was done by Coopers. How much of this is fragility was due to design error, and how much was due to race preparation by Team Lotus is debatable. Lotus designed a positive stop gearbox without a conventional gate for the 18, it became known as the 'queer box' because as the internals wore, gear selection became somewhat random. It is probably no coincidence that the two most famous victories by this chassis are for cars prepared for Stirling Moss by the privately run RobWalker Team.

Lotus 25/33 (1962-1966)

Era. A 1.5 litre formula had been introduced in 1961. The British had attempted to revolt against the FIA with the intention of retaining the old 2.5 litre formula, they lost. One consequence of this for the British teams was that in 1961 the only engine available to them was the four cylinder Climax producing less than 100bhp/litre. Ferrari had a V6 with a distinct power advantage. For 1962, somewhat late, Coventry Climax and BRM produced V8s.
With near identical power plants, and so little power available, every effort was made to reduce frontal area and weight. This was the era of cigar tube shapes with body panels wrapped tightly round straight tube space frames. Lotus used similar chassis for their commercially available: FF1600s, Juniors, F2 and F1 cars.
Description. Having just taught F1 designers the correct way to construct a space frame Chapman changed the goalposts. His twin D section monocoque was neat, practical and so obviously correct that every other car was rendered obsolete. The 25 reclined the driver, it was stiffer but lighter, had smaller frontal area, and lower C of G. With all these advantages the surprise is that season was not a walkover for Lotus, Graham Hill took the championship for BRM. But Jim Clark and the 25 were nearly unbeatable the following year.
Achilles heel(s). The untested car was wheeled out for the first time at Zandvoort and inevitably there were teething problems, but by the standards of the times the number 1 Lotus of Jim Clark was reliable. There were persistent problems with the rubber doughnuts on the drive shafts. The story for the number 2 Lotus was dire, this seat proved to be the end of several careers.
Dunlop effectively had a monopoly on tyre supply, but they maintained tyre development. The 33 was effectively an updated 25 with appropriate suspension changes to take full advantages of Dunlop's lower profile tyres. The 33 was still on the pace when the 1.5 litre formula ended in 1965, and on occasion it was wheeled out the following year, the first year of the 3 litre Formula, publicised as ‘The return to power’.

Lotus 49, (1967-1970)

Era. History repeated itself in 1966, when the new 3 litre formula was introduced there was a complete lack of suitable engines. Brabhams won the 1966 and 1967 championships using a single cam per bank Repco V8 based on an Oldsmobile block, installed in a space frame chassis. Chapman was instrumental in persuading Ford to commission a modern V8 from Keith Duckworth's Cosworth concern. Duckworth's design was well thought out, and once some problems with timing gears were sorted, it was reliable. The DFV remained competitive into the turbo era. Winning its first race in 1967, and its last in 1983, overall it powered to 155 race victories in GPs. At the end of its first season Chapman magnanimously allowed his exclusive contract for the DFV to lapse, and F1 became the DFV version of Formula Ford with only Ferrari occasionally offering a challenge.
The 49 was the first GP car to appear in fag packet livery as Chapman sought to finance his F1 activities with money from sources outside the motor industry.
Description. Up to the engine bulkhead the 49 is similar to the 25 but the DFV was designed to be structural, and was bolted to this bulkhead, the rear suspension was bolted onto the engine and gearbox, this saved weight and improved accessibility.
The 49 existed during the evolution of wings. From primitive beginnings F1 cars became biplanes. Predictably, Chapman's wings were the most extreme, ultimately they were ‘located’ on struts resting on the uprights. Identical crashes caused by the failure of these wings on both of the works Lotus cars during the Spanish GP bought the era of high wings to a close.
Achilles heel(s). After the high wings were banned by the FIA there were not too many problems. Unfortunately, the first season was marred by engine failures due to overtorqued spark plugs! Drive shafts could fail.

Lotus 72 (1970-1974)

Era. With the best engine in F1, the DFV, being available to all constructors, it was down to the team to attract the best drivers by providing the best chassis. The 49 layout was effectively the design standard, and even the lumpen March 701 won races in Jackie Stewart's hands. To gain an advantage Chapman thought outside the box, and came up with the layout of the modern single seater.
Description. The monocoque was of traditional Lotus structure, but the 72's profile was wedge shaped and was intended to produce downforce. It had an empty nose because it had side radiators to aid driver comfort, and alter the weight distribution. With the intention of improving traction, suspension was rising rate by torsion bars, and originally featured anti-dive, and anti-squat. The brakes were inboard.
Colin Chapman took his sponsorship deal one step further when he entered the 72s, painted black with gold detailing they were entered as John Player Specials, or Just Plain Sexy if you are Ian Hughes.
Achilles Heel(s). Once it was sorted the Lotus 72 became a very successful race car, but one gets the impression that drivers were always a bit wary of it. Naturally it had a reputation for frailty, Rindt once bent a monocoque by spinning it, and the shafts to the inboard brakes came under suspicion, the failure of one of these shafts is blamed for Rindt's death.

Lotus 79 (1978)

Era. The idea of using an inverted wing section to generate downforce in a race car was not new, its most recent incarnation had been the unloved March 701, which had inverted stubby airfoil sections on its flanks. Such 'wings' were ineffective because the tip vortex prevented them generating a significant pressure difference between the surfaces. The Lotus team, stories vary as to who made the breakthrough, realised what is now obvious, seal the wingtip to eliminate the vortex, retain the pressure difference, and you have downforce.
Description. The Lotus 78 was really the car to make the breakthrough but its wing performance was compromised by side fuel tanks and a cluttered rear suspension. The 79 addressed these problems with a central fuel tank, and all inboard suspension. Unlike the 78, the 79 was a balanced car with an efficient wing. It gave Mario Andretti the championship.
Achilles Heel(s). Heat soak caused chronic brake fade, and as a consequence of the increased grip from the tyres, the chassis structure was not sufficiently rigid.

Lotus 88B (1981)

Era. In an effort to reduce downforce the FIA insisted on 6 cm ground clearance, naturally this could only be measured when the car was stationary, and was soon circumvented by devious designers, with the result that F1 cars effectively had no suspension, but for give in their tyres.
Description. The 88B had the chassis and body as separate units. The former was on compliant suspension, while the latter exerted downforce through springs bearing on the uprights. Chapman called this arrangement ‘twin chassis’, chassis being both single and plural word.
Achilles Heel. Moveable airfoils had been illegal since high wings had been banned after they collapsed on the Lotus 49s. The FIA were not convinced by Chapman’s semantics, and decided that the Lotus 88s body was a moveable airfoil, so they banned it. The 88B never raced as a GP car

Postscript. Colin Chapman resented the banning of the 88B, but had bigger problems to distract him, these were associated with John DeLorean's government financed plan to build cars in Northern Ireland. The adverse publicity resulted in several sponsors withdrawing from Team Lotus.

Colin Chapman died of a heart attack in December 1982. He was 54.

Post Postscript. Outside his motor activities, Colin Chapman also ran a company manufacturing large powerboats. He developed a new GRP moulding technique, naturally his hulls were lighter than the competition.

As a skilled pilot, Chapman became interested in microlights. At the time microlights were little more than hang gliders with lawnmower engines. He had plans to subvert the intention behind the microlight regulations by manufacturing a suitably light composite machine with a powerful engine, and got as far as commissioning the design of the engine. History shows that this concept was 25 years ahead of its time, but this begs the question, would you feel happy flying at 10,000’ in a machine stressed by Colin Chapman?

Patrick Huston

ps Ask one of the paddock hillclimb gurus about when CABC lent a year old F1 Lotus to his friend David Render for sprints and hillclimbs.....

A selection of classic Loti - how many can you name? Some are duplicates. A harder question - can you think of an ugly Lotus, because we can't.

Pictures by Nigel Bland, at Brands in the 1980's and Monaco 2010 and from Internet