Construction

The Biota Concept

" The broad concept was to assess the possibility of building a front wheel drive open two seater sports car similar to the Lotus 7; but based on the Mini front sub-frame complete with engine, suspension, drive shafts wheels, the whole works and design a simple space-frame chassis to attach it to some means of mounting the Mini rear suspension without its’ sub-frame, and modified to coil-spring damper suspension. The whole to be clad in a simple slab-sided open wing body with a substantial roll bar suitable for a kit-car conversion for mini components. "

- John Houghton

Evolution

The first step was a great deal of accurate measurement of new components at our local friendly, long suffering BMC dealer and also on complete vehicles on the ground and on garage lifts.

From this basic research two problems reared their ugly heads. Firstly; although there was shoulder room above the chassis top rail for the outer shoulders of the occupants, cockpit width was going to very restricted between the inner mounting points of the rear suspension bearings, if we maintained Mini track front and rear. Solutions: a) don’t use mini rear suspension arms; b) widen rear track; c) bench seat; or d) build a single seater. The width between the inner ends of the rear suspension arm bearings on the standard mini was only 36.5 inches and in 1968 an average shoulder width of 18 inches was not uncommon, particularly among the young. So there was room for two people using standard track, provided that they were prepared to be good friends, but not any form of standard or even racing seats. It was felt that the use of the min rear suspension units was essential to maintain the kit car concept and that widening the rear track would not help the appearance of what was envisaged as a small neat road-going, two-seater sports car.

Fortunately by 1968 seatbelts and Velcro were with us, so the adopted solutions were simple hammock/ deckchair type side less seats consisting of a beaded aluminium sheet suspended between 3/8 inch tubes, front and top with removable custom made ribbed upholstery including a movable lumbar pad all held in with Velcro. With the addition of the standard three-point seatbelts with their simple spring loaded clip third attachment device, common at that time, securing to a central shared raised loop, it `was felt to be adequate for two occupants provided they were good friends. The second and far more concept shattering problem, was the height of the Mini rocker cover. A quarter size model of the chassis was represented by a slightly wedge shaped (in vertical profile) rectangular block of wood, to which the crude but scale wheels were attached in scale position. To this was added a block representing dash face position and height, and a further scaled block was positioned to represent the exact location of the problem mini rocker cover.

Disaster….A simple Lotus 7 type open wing body was going to produce something resembling a pregnant fire engine and an all-enveloping body of some sort was going to be the only answer. Fortunately there was Peter Edley a first class Rolls Royce trained panel beater, who had produced the panels for the Coldwell Mink at a sensible cost. Preliminary discussion indicated that a scale model of the body shape, a chassis and full-scale templates of the curves were essential before Peter could accept undertaking the work. The model was then completed using additional timber, several sticks of plasticine and some wire and paper as illustrated here and in the bodywork section.

The first chassis complete with side body rails, rear body work and nose support frames (plus that borrowed mini sub frame), together with full size ply-wood formers for all the curved aspects. The formers were scaled up from the model and cut out by a kind local joiner friend Ron Wilkinson.

By this stage the unavoidable all-enveloping had begun to acquire some refinement and character. Gone were the headlamp fairings and the power-bulge had become an air scoop, but remaining an integral part of the one piece lift-off front. After the 69 Racing Car Show further developments occurred requiring temporary removal of the aluminium body from the chassis to facilitate the fablon flashes being converted to 20 mm deep indentations with improved exhaust exit hole. Curving of the profile of the rear of the roll-bar cladding and recesses for the badges. Major changes were also made to the power bulge/air scoop. The vertical profile was flattened and lengthened and the front made more rectangular in front view, together with making the whole of the scoop detachable to improve access to at least the top area of the engine etc. Apart from appearance these modifications increased the strength of the panels mentioned considerably and highlighted the thinking towards a composite body chassis unit particularly when in GRP and thus improving torsional rigidity. This was particularly beneficial on the competition version of the mark II, enabling the use of a lightweight bonded shell without loss of structural integrity.