Esprit S1 S2 Design

With Giugiaro's Esprit design work on the form of the car complete, it was over to Colin Chapman and his team to add the engineering know-how to turn the "SilverCar" into a production version

The test bed for the proof of production concepts was "The Red Car" (shown on the left)

This working prototype, once completed, wore the registration number IDGG 01


Chapman and Mike Kimberley, the head of Lotus Chief Engineer, flew to Turin weekly in Colin's Private aircraft and the task of changing the car into a design that could be produced in GRP by the Lotus patented VARI (Vacuum Assisted Resin Injection) technique was tackled - this invloved efftectively splitting Giugiaro's design in half along its length, in order that it could be cast in two halves, which would be joined together along the seam halfway up the sides

Colin Chapman wanted ďThe Red CarĒ production prototype ready for him to evaluate by Christmas 1974 - this didnít quiet happen but the story goes that, when it was ready and road worthy in early in 1975, Tony Rudd surprised Chapman by picking him up at Londonís Heathrow Airport in IDGG 01,  when he returned from the Argentine Grand Prix


Colin Chapman reportedly got in and drove back to the Lotus factory and although a hub carrier broke, the car was declared a runner and Lotus would plan to reveal it at that year's Paris Motor Show

Lotus had first offered an exciting level of technology to enthusiasts at well below supercar prices with Europa, as the first mid-engined Lotus road car in 1966 - the basic design of the Esprit, with a steel backbone chassis and in-line mid-engined layout, was broadly similar and, as stated, an extended Europa chassis was used for the early design work at Ital

The overall Esprit concept was quite different though and, aimed for the big league, the Esprit was 13ft 9in long and 6ft 1in wide, making it 7in longer and no less than 9in wider than the Europa

The backbone chassis was finalised and the front suspension was based on the Opel Ascona/Vauxhall Cavalier - Steering was rack and pinion, withouy power assistance, which was not used, even on the future S2, S3 and Esprit Turbo designs

Rear suspension was as simple as possible for an independent design, using the "Chapman Strut" of fixed-length driveshafts also being used as upper transverse links, with tapered box-section semi-trailing radius arms and lower transverse links

Dual-circuit Girling brakes, without servo assistance, were used with solid but unventilated front and rear discs - the rear discs mounted inboard

Lotus was by now built its own engines, moving upmarket and away from the old kit car image and the the engine for the new Esprit came from the Lotus development program of its own alloy 4 cylinder unit, the 907

Team Lotus had been used to test the basics of the engibe design, by running the earlier 904 engine in the Type 62 racing car

The 904 used a Vauxhall 2 litre iron cylinder block with a Lotus specified long stroke crank and a Lotus prototype cylinder head, which is naturally the more inlvoved area of design  - this accelerated the process by using the cylinder block from slant four Vauxhall Victor 2.0, which had a "remarkably" similarly sized bore arrangement...




The engine was in a line of planned Lotus competition and road engines:
Type 904: 2-litre iron block race engine

(LV220 Lotus-Vauxhall)
Type 905: 2-litre iron block road engine
(non-production, test only)
Type 906: 2-litre sand-cast alloy block
race engine (LV240)
Type 907: 2-litre die-cast alloy block road engine
Type 908: 4-litre V8 alloy block race engine
Type 909: 4-litre V8 alloy block road engine
Type 910: Die-cast aluminum block
2.2 Turbo road car engine
Type 911: Die-cast aluminum block
2.2 N/A Sunbeam-Talbot engine
Type 912: Die-cast aluminum block
2.2 N/A Lotus road car engine

The hybrid LV220 and LV240 engines names denoted the Lotus/Vauxhall build and rated horsepower - they were tested in a Vauxhall Victor, Vauxhall Viva GT and even a Bedford CF van! The all Lotus alloy 907 used the same 95.25mm bore as the Vauxhall, with a 69.2mm stroke and sunsequent 1973 cc displacement

The 907 marked the arrival of Lotus as an independant engine manufacturer and was very importnat to Colin Chapman

Unfortunately, the almost covert Lotus-Vauxhall program was seized upon by the motoring press and they risked his wrath by refering to the all alloy 907 as a Vauxhall or Lotus-Vauxhall engine!

The 907 was supplied to Jenson Healey as well as to Chrysler/Talbot for the Lotus Sunbeam

The CitroŽn C35 five speed manual gearbox/transaxle fitted to the CitroŽn SM and Maserati Merak was selected for the Esprit - production of the SM was actually ceasing but CitroŽn agreed to continue production to support the Esprit 

Esprit S1

The S1 Esprit entered production in June 1976 and, with a light weight of 1,984 lb, its performance figures were considerable for the day - with the relatively small 1,973 cc  907 slant-mounted four-cylinder, double-overhead-camshaft, aluminium engine with twin Dell'Orto carburetors producing 160bhp at 6200rpm, with maximum torque of 140lb ft at 4900rpm

Wheelbase    2,438 mm (96.0 in)
Length    4,260 mm (167.7 in)
Width    1,861 mm (73.3 in)
Height    1,111 mm (43.7 in)
Kerb weight    900 kg (1,984 lb)

The Esprit S1 was renowned for its green and red tartan interior, as seen in the James Bondís car

Tony Rudd and Mike Kimberley in an impromptu, or more likley staged photo, looking like they could be ready to discuss the developments needed on the Esprit S1 and the future models

Giugiaro Designed Esprit Models

Esprit - 1976 - 1977
Esprit S2 - 1978 - 1981
Esprit JPS (John Player Special) - 1978 - 1979
Esprit S2.2 - 1980 - 1981
Esprit Essex - 1980
Esprit S3 - 1981 - 1987
Esprit Turbo - 1981-1986
Esprit Turbo HC - 1987

Esprit S2

In 1978 the S2 Esprit was launched with improvents learnt from the S1

The Wolfrace wheels of the S1 were replaced with Lotus designed Speedline alloy wheels and the S1 Fiat X1/9 rear lights were dropped for Rover SD1 variants

Cooling ducts were added to the back of the rear quarter windows and the front spoiler was redesigned by Giugiaro

Changes to the interior included, wider seats and a revised dash/binnacle layout with seperate Smiths gauges replacing the S1 Veglia instrument cluster and different illuminated switches

Series 2 Esprit bodies being mated to the rolling backbone chassis at the Lotus factory, Hethel

Colin Chapman had already put the black and gold JPS livery of John Player & Sons on his Cessna 414-A Chancellor II private aircraft, which also had the registraion G-PRIX but after Lotus won the 1978 F1 World Championship, a commemorative edition Esprit was announced

Esprit S2 JPS Commemorative Edition

The Lotus Esprit S2 Commemorative Edition Esprits were mechanically identical to the standard Esprit S2 but featured the JPS black & Gold livery, in the form of black gloss paint with Gold side stripes and World Champion decals and gold wheels - a total of 100 of these cars were built

World Champion Car Constructors badge, with all 7 years as champions listed, were added to the tailgate and an individually numbered plaque on the dashboard, with Colin Chapman's signature

Esprit S2.2

May 1980 saw the introduction of the Esprit S2.2

The engine capacity was increased to 2.2 litres and with it, power was unchanged but torque rose from 140 ft-lbs to 160 ft-lbs

The S2.2 chassis was also galvanised but its design was unchanged 

In a short run Lotus only produced 88 of these models

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Click here for the next part of the Esprit developement - The Turbo Esprit