- 1,115
- Rivera
- Tsukishima-TDUDT
The Canadian American Challenge (Can-Am) has gone into history as the no-regulation series that invited designers and drivers to really push the limits of physics. This resulted in some of the most powerful and strangest racing cars ever constructed. Towards the end of the 1966 - 1974 era, the governing body was forced to introduce restrictions. The last season that really bristled with innovation was 1970 with the introduction of the Chaparral 2J, the quadruple engined Hoare Mac's-it Special and the Shadow MkI. The latter could very well be the most unusual machine to ever turn a wheel in anger.
The story of the Shadow MkI started in 1968 when Don Nichols moved to California and founded Advanced Vehicle Systems (AVS). The former military intelligence officer had already worked in motorsport as a supplier of parts and tires and race promoter in Japan, but always on the background. Nichols' company was later renamed Shadow, no doubt a reflection of the owner's character and previous occupation. That year he met freelance designer Trevor Harris, who had mastered the skill to think outside of the box. His wildest idea was to install a big-block V8 engine in a chassis as low and compact as a go-kart. Nichols was quite taken by the idea and commissioned Harris to draw up the designs for a 'full size' version.
With this design Harris tried to create racing car with as little drag as possible, by dramatically decreasing the frontal area. Not surprisingly the ultra-compact design did create many packaging problems. The most conventional part of the car was aluminium monocoque, which was anodized black for additional strength. Suspension was by very short, double wishbones all-round. There was no room for conventional springs and dampers, so Harris fitted three tiny (valve) springs at each corner together with friction dampers, inspired by a 1930s Maserati racer. The 10 inch front and 12 inch rear wheels were shod with custom made Firestone tyres, designed to withstand well over the theoratical top speed of 403 km/h. The initial plan was to use an air-brake, but when moveable aerodynamic devices were banned, the small racer had to rely on machined down Ford Mustang vented disc brakes.
For packaging reasons, a Toyota quad-cam V8 was considered, but that idea was discarded in favour of the much easier to obtain and maintain Chevrolet big block. The engine was mated to a Hewland five speed gearbox, with altered gears to allow for a higher top speed. There was only room in the cockpit for two horizontally mounted pedals, so a hand-clutch was fitted. This was only used to take off as the gearbox was modified to survive clutchless shifts due to an ingenious lubrication system. A later development included an automatic clutch operated by a button on the gear-lever. The exceptionally low chassis was tightly wrapped in a fiberglass body. At the front there were the first signs of ground-effects as the underside was shaped like a wing. The car was so low that Nichols considered it a two-dimensional car, which is supposedly why he called it 'Shadow'.
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