Page 1 of 2 Next >> With the Type 15 launched in the spring of 1958, Lotus moved up the order and offered a sports racer that could challenge for class and even outright wins. It was designed around the new Coventry Climax FPF four cylinder engine, which had originally been developed for single seater racing and was available in various sizes, ranging from 1.5 litre all the way to 2.5 litre from 1959 onwards. As such the Type 15 was not as much a replacement of the popular Eleven but an addition to the Lotus line-up and effectively a replacement of the Bristol-engined Mark 10 built in 1955.
The new sports racer was built around a steel tubular spaceframe that shared its basic design with the Eleven chassis but was further strengthened in critical areas to cope with the bigger and more powerful FPF engine. The aluminium floor and transmission added further rigidity to the frame. Equipped with the patented Chapman struts, the Type 15 was the first Lotus sports racer to feature independent rear suspension. The double-wishbone suspension used at the front was carried over from the Eleven. Lotus' proprietary five-speed transaxle was used, better known as the 'Queerbox'.
Based on the stillborn Coventry Climax FPE V8 Formula 1 engine, the all-aluminium FPF was designed for competition use from the outset. It featured a twin-cam head and dry-sump lubrication. Breathing through two Weber carburettors, it produced 141 bhp in 1.5-litre trim and as much as 220 bhp in 2.5-litre form. To lower the frontal area, the engine was angled 28° to the left. The rolling chassis was tightly wrapped in a slippery aluminium body built and designed by specialists William & Pritchard with some input from Colin Chapman himself. Page 1 of 2 Next >>