The Lotus Esprit Turbo

The Lotus Esprit Turbo

IN THE March issue of MOTOR SPORT we published a description of the new Lows Esprit Turbo. Production is now at five a week. The first 100 will be numbered, Essex Commemorative models, liveried like the unnumbered prototype depicted here. Less conspicuous versions will follow. It is unlikely that a road test car will be available for some time, but recently I was fortunate enough to drive the prototype from the Hethel factory foes couple of hours. Full technical details can be gleaned from the March story, but briefly, the mid-mounted

16-valve, four-cylinder engine has been enlarged to 2,174 c.c. (92.25 mm. x 76.20 mm.), is dry-sumped, endowed with a Garrett T3 turbocharger boosting through two, twin-choke Dellorto carburetters at a maximum 8 psi., and delivers no less than 210 b.h.p. DIN at 6,250 r.p.m. and 200 lb. ft. of torque at 4,500 p.m. The backbone chassis is considerably modified at its front and rear ends, the engine/transmission is slung ioases space frame with four-point, wide base mountings to reduce NVH, and there is new suspension all round, that at thc front being adapted from the Elite, with wider track front and rear. Aerodynamic changes include a deep front spoiler, side skirts incorporating NACA ducts to provide cooling airflow to the engine compartment, directed by an undertray beneath the engine and finally exiting through ducting louvres in the rear hatch, which replace the standard Esprit’s rear windows.

Beings modest 5 ft. 7 in. tall, I find the reclined driving position of the low-built Esprit one of the most comfortable of all — taller people mightn’t be so happy — and relaxed straight away into the Turbo’s ruched leather upholstery, with Roger Becker, Lotus’ bright young Senior DCVelOpMCIII Engineer in the “hot-seat” alongside me for an exciting drive through the Norfolk countryside. With pleasant memories of the Esprit S2 road to car behind me (MOTOR SPORT, March 1979), I expected this to be an experience to savour. The comparison turned out to be astonishing. In the Turbo, Lotus have a car which is not just a modified Esprit S2, good in its own right, boss sensational newcomer which without doubt in my mind sets new World standards in production turbocharging and road car handling. I woul venture to say that whilst it might not be the World’s fastest production car, though with 0-60 ESPRIT TURBO — continued

m.p.h. in 5.55 sec., 0-100 in 14.65 sec. and a 152 m.p.h. maximum it is not far off, it is the World’s fastest production road car in terms of usabk performance.

The instant impression was one of substantially improved refinement over the Esprit S2. While a little bit of vibration can be felt at low speeds, the annoying body booms and other NVH problems have been almost totally eliminated. There is little wind noise, the turbocharger deadens the engine noise (though there is considerable intake noise if the driver’s window is lowered) and Becker and I were able to converse easily at 130 m.p.h. plus. The Lotus engine is uncannily progressive in its throttle response and power delivery. literally to the extent that if nobody mentioned it, you would be unaware that it was tubocharged. The throttle can be floored in fifth at 1,000 r.p.m., and except for a quick hiccup at 1,200 r.p.m.. the power delivery proceeds utterly smoothly. with no sensation of the turbocharger coming in. By 4,000 r.p.m. in any of its gears the turbo is accelerating like a rocket. Flexibility at low speeds is superb, to the extent that in spite of Becker’s grimaces I was able to let it trickle along in fifth at tickover. Throttle lag? This Lotus has never heard the term. This beautiful engine is matched by simply brilliant handling and roadholding. I could feel the chassis’ cxtra torsional stiffness over the S2 instantly; the Turbo feels utterly taut. It is so

responsive and nimble that its great width felt to shrink to bicycle dimensions through the Norfolk lanes, its handling so well balanced and steering so positive that this is a car which feels to be driven directly from one’s brain, without muscular intervention. Where at high speeds in the dry the Esprit S2 has a slightly unhappy transicnt period to oversteer which can catch Oct the unwary, the Turbo is totally forgiving and its roadholding — on Pirelli P65 on the test car, Goodyear NCTs in production (Becker says the NCTs give slightly better turn in, the P6s a better ride/roadholding compromise) — staggering. Indeed the Turbo will pull 1.04g and 113 m.p.h. round an 820 ft radius curve. against 0.86g and 103 m.p.h. for the S2 and on the road feels as though it will never “let go”. Becker placed special emphasis during development on ..emergency handling”, i.e, the way the car will respond to sudden directional changes. Matched to all this is a very acceptable ride and low roll angles. I’m afraid I cooked a set of new brake pads initially, but they recovered to give tremendously powerful stopping, via larger, solid front discs. I wish space restrictions had not convoluted this report so much. There is so much more to say about this all-British, miti-engined sports car which basset handling standards for Ferrari and Porsche to aim at. instead of the other way round, and a turbocharged engine which makes the Porsche 924 effort. with ics lack of progression. look totally inferior. — C.R.