The classic original Esprit design is commonly referred to as the
Giugiaro Esprit; named after the
Italian designer of the car, Giorgio Giugiaro, or Giorgetto
Giugiaro, as he was usually called, who was regarded as
perhaps the most talented continental designer of the period
In the early 1980's a turbocharged engine and more
aggressive aerodynamic styling changes were added to the design,
which had first appeared at the 1972 Turin Show as a concept car
(read more in the Esprit S1 &
S2 section)
It was then that Colin Chapman,'s flair and
vision truely combined with the Giugiaro's creativity, to produce
a real world-class Supercar.
The hand-built Turbo Esprit bears many of the
hallmarks of a Grand Prix manufacturer of the period,
including mid-engine layout with the main masses centered low
and well within the wheelbase, rear wheel drive through tyres
of significantly wider section than those at the front,
low-nose bodylines combined with down-force aerodynamics from
a front air-dam and rear lip-spoiler , in-board rear disc
brakes (a la Lotus 72 GP car) for added reduction in unsprung
weight
All these design changes, plus lavish new trim and luxuries such
as electric windows all added expense, so that, at £20,900, the
Turbo Esprit was actually more expensive than the rival Ferrari
308GTB, Porsche 911 SC Sport etc.
It was also, at last, the quickest among them
Lotus had been working on Project M71, the V8
engined Esprit, but the rising petrol prices from the oil crisis
of the 1970s produced the need for a Lotus factory designed
turbocharged Esprit
In 1980 a commemorative edition of the Esprit was
unveiled at the Royal Albert Hall, at an event hosted by the Essex
Overseas Petroleum Corporation, the then main sponsor of Team
Lotus in Formula 1
The cars were only available finished in the Essex
colours of blue, red and silver and, although the planned
prodcution was for 100 commemorative cars, only 34
production Essex Turbo Esprits were produced
The cars were fitted with a new 2.2 litre 910-turbo
engine producing 210bhp, with a Garrett AiResearch T3 Turbocharger
providing 8 PSI boost, giving 210 bhp and 200 lb ft torque at
4500rpm - the engine also had a dry dump oil system, with a
toothed-belt oil pump, driven off the crankshaft and two scavenge
pumps
The galvanised chassis and rear suspension were
updated, with the "Chapman Strut" being replaced with an
additional upper link and plunging driveshafts
The braked were uprated and the car was fitted with new three-piece 15 inch Compomotive wheels
Giorgetto Giugiaro was recalled to designed an aerodynamic body
kit for the car, which included a louvered rear tailgate, a larger
front air dam, NACA in side skirts and larger bunpers
Red leather was used for the interior and a unique roof mounted Panasonic stereo - the dash binnacle now also had a boost gauge mounted between the speedo and rev counter
The rest of the car was also substantially re-engineered, with changes to the appearance but the most important developments were under the skin: a galvanised chassis with a wider front box section and suspension mounting points: new engine mountings to reduce vibration; pure Lotus parts to replace the Opel elements in the front suspension; improved rear suspension with lower wishbones and a new upper link - Torsional rigidity was well up, vibration was down and relieving the driveshaft from functioning as the upper rear suspension link also gave a reduction in transmitted NVH (Noise, Vibration & Harshness)
The production Turbo was probably over-engineered, even by Lotus standards, as the photo below shows (exhaust manifold and turbo, glowing cherry-red with heat during extended engine testing) - the Turbo Esprit exhaust manifold was cast in high-silicon molybdenum iron, with a 4 into 2 tract configuration and pre-turbine temperatures and pressures of 1000 degrees C and 12.5 psi have been recorded
The wastegate commenced opening at 2,500 rpm, under influence of
the inlet manifold pressure, and discharged into a separate small
bore outlet, which met the large bore pipe at the large-capacity
silencer box - low rpm operation combined with a specially shaped
diffuser inlet pipe and small plenum chamber, combined to give
excellent low-end torque and virtually no throttle-lag and
effectively mimicing a larger capacity, multi-cylinder unit
A blow-through pressurised carburation system was employed,
with a Garrett AiResearch T3 turbocharger feeding smaller twin
40 Dellortos and modest maximum boost of 8.0 psi (0.55
bar) at 5,500 rpm, corresponding to a peak turbine speed of
110,000 rpm, was controlled by a wastegate exhaust gas bypass
system
The specially developed Dellorto carburetors were sealed to allow
air to feed at boost pressures from the plenum chamber and, in
order to maintain petrol vaporisation, the fuel pressure was
maintained at a constant 4.5 psi above the inlet pressure by means
of a regulator valve
A number of improvements in design were made to the 910 turbo
engine to cope with the increased thermal loads: these included sodium-filled
exhaust valves with hidurel guides and Stellite valve seats
- pistons had a reduced crown height and enlarged dish, giving a
compression ration of 7.5:1, along with lower ring packs and
modified skirts to combat higher cylinder temperatures
Early Turbo engines also had dry-sump lubrication to aid oil feed under high lateral loads
The fully redeveloped 910 engine
produced 210bhp at 6,250 rpm and a massive 200
lb/ft torque at 4,500 rpm with 100 lb/ft torque at a
mere 2,000 rpm, which is more than it's normally aspirated
cousin achieves at maximum revs!
This truely endowed the Turbo Esprit
with rocket-like pickup from a standing start and
excellent over-taking performance in the higher gears
In the mid-Seventies it was invigorating to see such a fresh,
boldly executed, utterly modern sports car
It was very close to Colin Chapman's heart: he was determined to produce it, whatever problems Lotus faced
The Giugiaro Esprit (and indeed, the later 80s
Esprit) GRP bodies are made in very large molds in the Lotus
factory in Hethel - the only real difference the 80s shaped Esprit
and a Giugiaro shaped Esprit is the mold that is used (and the
fact that the Giugiaro shape now looks cooler again - 80's curves
are out!)
The bodies are made in 2
sections, upper and lower, and these are then glued
together - Here on the right a Giugiaro top section just
coming out of the mold
Below that are several Giugiaro shells nearing
completion and below the vidoe show production at the Hethel
Lotus factory
"As a driver, it's hard not to love this car; in true Lotus tradition it became a great driving machine, with extraordinary roadholding and an unusual subtlety of handling. There's a strong feeling of 'real racer' about it"
Here's the opinion from Classic Car
"Before anything else is said, let's be clear about one thing:
the Lotus Esprit became one of the greatest drivers' cars ever
made for the road. That is the simple truth of it.When the
Esprit first arrived it was considered interesting but not fast
enough to deserve the tag of 'supercar'. The earliest Esprits had
phenomenal roadholding and simply astonishing traction but
the steering feel was below Lotus standards; worse, the noise was
enough to drive you mad. But few British drivers ever experienced
an S1, as virtually all of them went abroad. Fortunately, the
energy within Lotus was such that the Esprit rapidly became good
enough to own and live with. Performance was steadily improved:
the normally-aspirated 2.2 achieved 0-60mph in 6.5sec. with an
estimated 135mph top speed"
"The Esprit was greatly improved with the introduction of the S3 and Turbo: the original Essex Turbo managed 0-60mph in 5.6sec, with a claimed 152mph maximum. Furthermore, the Turbo had unexpectedly excellent torque from low rpm, with no sense of a 'step' in the curve as the turbo came in; yet all Esprit engines are happy at high engine speeds, too. The quickest Turbos were rather 'fussy' but all blown Esprits are firmly in the supercar performance league"
"The experience of handling a mid-engined car with its engine
mounted longitudinally is rare enough: in an Esprit, the sense
of balance, surefootedness in the wet and feeling of control when
driving fast are strong sources of pleasure. You need to be
something of an expert to explore its high roadholding limit - but
only because it is so high. The ride is unusually good, too: with
no lump of engine ahead of you, it's uncanny the way the front
wheels handle bumps and irregularities in the road. Lotus was
always superb at showing that lightweight, pure sports cars can be
made to ride well and the Esprit is an outstanding example"
Use the buttons above
for more
Click here for the History of Lotus,
the 007 Esprits and the 909 V8 engine