Lotus Type 50 - Elan +2
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Method of construction

The Elan +2 has a glass fibre body shell which is bolted on to a steel backbone chassis, to which the engine and suspension are fixed. A layer of felt insulation material lies between the chassis and the body to deaden noise and vibration.

The chassis

The chassis forms the backbone of the car, having a central box section, from which splayed and braced arms extend front and rear.  These arms end in box section uprights, the upper end of which form the top anchorage of the suspension uprights.
At the rear the upper end of the suspension spring \ damper unit are attached to the chassis by flexible mountings, referred to as Lotocones. At the front of the chassis the suspension is mounted on welded in pins.

The chassis is made of mild steel and the front cross member also performs the role of the vacuum tank used to raise the retractable headlight pods. 
The engine, transmission and differential are all fixed to the chassis. The engine is carried by two brackets, one each side of the cylinder block, and a mounting plate underneath the gearbox. Rubber blocks are used to cut down the vibration being carried into the cockpit. From Chassis 50/0521 onwards additional welding was used to stiffen the chassis further.
The chassis was undersealed at the time of production, although very few surviving Elans will be on their original chassis now, as corrosion and accident damage will have taken their toll over the years. The vast majority will now have a replacement Lotus galvanised replacement chassis or Spyder spaceframeunits.

The Body

The basis of the Elan was a single piece glass fibre reinforced plastic (GRP) body which straddled the backbone. Whilst the vast majority of the structural rigidity was provided by the backbone, when mated together the body and chassis each contributed to the strength of the other.
The body was made up of an upper and a lower moulding, together with a front undertray chin piece. Within the body a steel side member is bolted within the sills, which gives some measure of protection from side impacts.
Generally the panels are about .125 inches (3.17mm) thick, with thicker areas where additional strength was needed around structural attachment points, seat mountings, floor areas and wheel arches.
In these areas the thickness increased to up to .25 inches (6.35mm).
Separate mouldings for the headlight pods, doors and boot lid completed the body.
Within the body die cast metal metal inserts, known as bobbins, were used to provide secure and accurate mounting points.
Lotus have produced a range of body repair sections, enabling accident repairs to be made by grafting a new section onto the undamaged areas of the car.


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