Enlightenment

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The inline 4-cylinder (1.5L, then 1.6L in 1962) was derived from a Ford Anglica, but after Keith Duckworth and Harry Weslake got finished with the Al alloy head it made 105 hp at 6,500, fast enough to turn 7.0 second 0-60 mph sprints (let's see... how fast was the 911 a few years later?).

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The suspension combined very soft springs with long suspension travel (like the famed BMW 2002), firm shock absorbers and the geometry of a race car.



It all added up to a great mix of “compliance, forgiveness and feedback.” Gordon Murray is quoted as saying that his one regret about the McLaren F1 was that he was unable to give it the “perfect steering” of an Elan.

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The front suspension used twin A-arms and the steering rack from Triumph Spitfires. A better geometry than the 911, and one used today for nearly all sports cars.






The rear suspension used struts and tubular A-arms. Again, I see this as a superior geometry than the semi-trailing arm on the 911, which presents the exciting surprise of camber changes from + to -

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The Y-shaped backbone frame weighed only 75 lbs., yet the chassis has a torsional stiffness of 8,948 M-m per degree – 6x that of a contemporary F1 car - R&T, Dec. 2012, p. 71. The Porsche 911 had a torsional stiffness of 2,719 N-m per degree (reported by M. Donahue (1970’s)), only 1/3 as stiff as the Lotus.


That Y-frame never got used again by other designers -- maybe it was too noisy for a production car? But, it is often cited as key to the light wt. and superior handling of the Elan.

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While not the most beautiful body ever put on a sports car, the Lotus was attractive enough to be featured in a TV series, and with various attractive women.

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Colin Chapman was a pioneer, not a settler, and the car was never developed, never honed over time as the 911 has been. The frames cracked, service access was difficult, and engines leaked oil. The Weber carbs leaked fuel (right onto the ignition) and it had Lucas electrics. Today few survive.





Just concentrate on that wonderful steering, suspension, and the 1,500 lb. weight.

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Peter Egan praised the “light and tactile steering,” and “supple suspension. He felt like there was zero weight-transfer in corners, even as he recognized that could not be true in reality. R&T, Dec. 2012, p. 74.

Today, the Miata harkens back to the Lotus Elan – though a 1992 Miata weighs 2,200 lbs. Here is a Miata chassis:





Peter Egan drove both back to back, and found the Elan about 15% sharper in transient response than the Miata could offer, though the Miata definitely reminded him of the Elan. Long-time Miata owner John Krewson felt that the Elan was the car his Miatas had always pretended they were – but only on a good day. R&T, Dec. 2012, p. 68. The Elan could plane out all the unimportant parts of the road, show off its eager engine, and pass along all the information from the tires -- fluidly.

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The Lotus Elan is, as Egan puts it: “the ballet slipper of sports cars.”

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back to the future...

Here are some comments from Claudio Santoni, Manager for the Body Functional Group at McLaren:

major advantages of using carbon fiber (CF) are crushworthiness, lightness, dimensional stability, stiffness, and packaging (he noted that you could easily optimize cabin space by designing curved shapes wherever wanted)

- it's interesting that he listed crashworthiness -- makes it sound like CF is better than using a deformable structure like steel or Al

biggest challenge to use of CF is scaling of the manf. process and to make that economic

he also notes they are now using a resin transfer molding process that is highly automated

one limit to using CF for the entire body is the heat in the engine compartment (he was talking about the 12C and its use of Al) -- that would require a special type of CF

he also noted that another advantage of CF is that it has a very long fatigue life and referenced aircraft airframes and the new 787 in that comment

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http://www.nytimes.com/2013/07/14/automobiles/carbon-fiber-light-and-strong-arrives-where-its-most-needed.html?hpw

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Will Aluminum Unibodies Die Out?