Turbo Esprit



Engine: Lotus Type 910 4-cylinder, turbocharged (2173cc)

Gearbox: Citreon Maserati SM 5-speed
Chassis: Steel backbone
Power/Torque: 210 bhp @ 6,500rpm, 200ft/lbs torque @ 4250rpm
Performance: 0-60 in 5.5 seconds, top speed 150+ mph


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.






Turbo Esprit (Lotus Type 82)


Production started in 1980 and ended in 1987
Introduced 1980 as Essex version
1981 Standard colours added to range
1983 Dry sump deleted
1984 Glass sunroof introduced
1985 Front uprights and brakes changed
1987 HCI version with Renault R25 gearbox




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



Turbo Esprit Devlopment

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






Surrey based Lotus dealer Bell & Colvill had produced a turbocharged Lotus Esprit, based on the S2 model, as the video on the left shows

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



 

Essex Turbo 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










Turbo Esprit

Announced in 1980, after the forced abandonment of the Project M71 Esprit V8, the Turbo Esprit brought real performance at last and actually the turbocharged engine had been developed successfully and more cheaply in parallel with the ill-fated V8 - Lotus engineers developed a turbocharged engine with good low speed performance and top end power, combined with immediate throttle response throughout the rpm range

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























































A key point of the lasting appeal of the Esprit must be the mixture of passenger car engineers and race team personnel who worked on it - this produced a remarkable machine and right from the start it had the vital ingredient of being exciting, both to those within the factory and to the world outside

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






Making the Giugiaro Esprit

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













The finished product!

Read more on Esprit production at the Lotus Hethel factory here



Driving the Giugiaro Turbo Esprit

"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"

More first hand experience:

"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"





Giugiaro Esprit Active Suspension Program



Having started research into active suspension in 1981, Team Lotus ran an active F1 car in Brazil and Long Beach in 1983 with Nigel Mansell

The software was improved and  raced again in 1987 with the Honda powered 99T, which won 3 races in the hands of Ayrton Senna

In 1983 Lotus Engineering used the Giugiaro Esprit as the development platform for active suspension technology in a production car

As the article on the left and video below explain, the hydraulic actuators used to replace the springs, came from the aerospace industry - but was the software rather than hardware, that took up the most development time and data aquisition on road tests took up many hours

 Click the article for the details











Click on the articles below for more on the technology and Nigel Mansell's experience of driving the active Esprit


































Deconstructing the Turbo Esprit


Finally for your amusement, we have a fully drivable Lotus Tubo Esprit, minus its body - click the photo for a full gallery








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Click here for the History of Lotus, the 007 Esprits and the 909 V8 engine