The Elfin Type 100 Mono is an

Australian 1½ Litre Formula The Australian 1½ Litre Formula was a motor racing category which was current in Australia from 1964 to 1968. The formula specified racing cars with four-cylinder unsupercharged engines using commercially available fuel and limited to 1500cc capaci ...

racing car produced from 1964-1969 by Elfin Sports Cars. The name "Mono" refers to the fact that it was constructed upon a monocoque design.

Development

In 1963, Garrie Cooper began work on a revolutionary monocoque design of a car intended to dominate the newly created Australian 1½ Litre capacity class.

Lotus Cars Lotus Cars Limited is a British automotive company headquartered in Norfolk, England which manufactures sports cars and racing cars noted for their light weight and fine handling characteristics. Lotus was previously involved in Formula One r ...

had already built the Formula 1 monocoque under the direction of Colin Chapman but the idea was still in its infancy so Cooper had only vague ideas of the design. The monocoque build removed the need for the traditional "Superleggera" tube frame chassis and harnessed a very light sheet steel frame to which aluminum panels were riveted for a very stiff structure. The finished structure weighed approximately 80 kg less than the tube framed Elfin Catalina it replaced. Uniquely, the hollow section of the body was sealed off to serve as the petrol tank. The Elfin Mono eventually made its debut at the August 1964 Melbourne Racing Car show and orders quickly followed.http://melbourneclassics.com/files/THREE_AUSTRALIAN_GPs.pdf

References

{{Elfin Type 100 Mono Tasman Series cars Cars of Australia