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
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
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 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
Below Colin Chapman discusses the Lotus 907 engine and it is shown
under test at the Hethel factory during the project M50 program
for the new 70s Lotus Elite - Colin also talks to the Elite designer,
Oliver Winterbottom, and Mike Kimberley and Tony Rudd, who went
on to develop the Lotus Esprit
The Citroën C35 five speed manual gearbox/transaxle fitted to the
Citroën SM and Maserati Merak was selected for the Esprit -
production of the SM was actually ceasing but Citroën agreed to
continue production to support the Esprit
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
The Esprit S1 was renowned for its green and red tartan interior,
as seen in the James Bond’s 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
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
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
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
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
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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the Esprit developement - The Turbo
Esprit