The Lotus Seven is a small, simple, lightweight two-seater open-top sports car, which has been called 'a motorcycle on four wheels'. It is characterised by extremely high acceleration and a mid-range top speed, handling is lively and the ride is 'uncompromising'.
The Caterham 7, is a direct development of the Lotus Seven designed by Colin Chapman and made under license.
The cars are constructed from aluminium sheet attached to a tubular steel chassis, brazed together by hand. Their extremely high performance is achieved through light weight (less than 500 kg on some versions) rather than particularly powerful engines.
Historically, engines have been supplied by Ford, using the Ford Kent engine or a Cosworth-derived race-prepared BDG unit, enlarged to 1.7 litres and generating 150 bhp.
Due to its low cost, the Caterham has been a favourite among club racers since the beginning of its career. In the United Kingdom, the Caterham is used in a variety of one-make series and sports car championships, both national and regional.
Due to its power-to-weight ratio, the Caterham has proved successful against bigger and more powerful sportscars, to the point that it has been banned from FIA competitions and most international races, coining the phrase "too fast to race".
Source:
http://www.absoluteastronomy.com/encyclopedia/c/ca/caterham_cars.htm