>>Lotus 2-Eleven

Lotus 2-Eleven

Lotus 2-Eleven
Overview
Manufacturer	Lotus Cars
Production	2007–present
Body and chassis
Layout	Rear mid-engine, rear-wheel drive
Related	Lotus Elise Lotus Exige
Powertrain
Engine	1.8 L supercharged 2ZZ-GE I4
Transmission	6-speed manual
Dimensions
Wheelbase	2,300 mm (90.6 in)
Length	3,822 mm (150.5 in) (road car)
Width	1,735 mm (68.3 in)
Height	1,112 mm (43.8 in)
Kerb weight	670 kg (1,477 lb) (road car)

The Lotus 2-Eleven is a car produced by British car manufacturer Lotus. It is based on the Lotus Exige S, and thus has the same supercharged Toyota 2ZZ-GE engine. Weighing 670 kg (1,477 lb) and with 252 bhp (188 kW; 255 PS), the 2-Eleven can sprint from 0-60 mph in 3.8 seconds and has a top speed of 150 mph (241 km/h). Intended as a track day car, it costs £39,995 though for an additional £1,100 Lotus will make the car fully road legal.

Slight differences exist between the track and road versions, where the track car is slightly longer, at 3,872 mm (152.4 in)and lighter at 666 kg (1,468 lb).

>>Lotus 19

Lotus 19

Lotus 19
Overview
Manufacturer	Lotus Cars
Production	1960–1962
Designer	Colin Chapman
Body and chassis
Class	Group 4 Sports Car
Body style	Fiberglass non-stressed
Powertrain
Engine	Coventry Climax FPF
Dimensions
Wheelbase	95 in (2,413 mm)
Length	141 in (3,581 mm)
Width	60.5 in (1,537 mm)
Height	31 in (787 mm)
Curb weight	1,000 lb (454 kg)-1,240 lb (562 kg) (dry)
Chronology
Predecessor	Lotus 15
Successor	Lotus 30

The Lotus 19 or Monte Carlo is a mid-engine sports-racing car designed by Colin Chapman of Lotus and built from 1960 until 1963.

The Lotus 19

The 19 is a mid-engine, rear wheel drive sports racer with a fiberglass body over a space frame, originally designed with 1.5 - 2.75L Coventry Climax FPF engine built for Grand Prix cars, mated to Lotus' own 5 speed sequential transaxle nicknamed 'Queer Box' which gave a lot of problems on Lotus 15, but was improved in its reliability for Lotus 18.

Chapman named the car Monte Carlo to honor Stirling Moss for his win at the 1960 Monaco Grand Prix. Lotus' first F1 victory. This is said to mimic and declare competition against Cooper Monaco, which was named after a win at Monaco in 1958.

The 19B

Towards the end of 1963, John Klug founder of Pacesetter Homes Racing commissioned Lotus to build a special 19 to be Ford V8 powered. Ford's new lightweight iron block 289 c.i. engine was chosen over Oldsmobile's smaller Aluminum V8. Roy Campbell finished the car in Southern California. Dan Gurney, who had enjoyed considerable success at the wheel of the Arciero Brothers Lotus 19-Climax was the driver.

Because of its unique specification, it was known as the 19B, the only 19 with this designation. Originally delivered in red livery, the car first appeared at Nassau in December 1963. In 1964 it was the fastest sports car in the world, but the car's weak spot was its Colotti transaxle, the failure of which led to a number of retirements. By mid 1965 it was just another old car. It continued racing in Southern California and eventually dropped out of sight. Wayne Linden of Roseville, California found it in a semi trailer waiting to be turned into a "dune" buggy. He restored it to early 1964 configuration except for the Colotti and ran it in mostly Cobra club events. He sold it to Gordon and Nancy Gimble. Today the car regularly appears at vintage car events in the US.

Chassis Numbers

There are 17 Lotus 19's built however many were wrecked and some were completely rebuilt. More cars are reported today than were built.

Chassis	Original Owner	Motor
950	British Racing Partnership	2.5 Climax
951	Arciero Brothers	2.5 Climax
952	British Racing Partnership Sold to Team Rosebud.	2.0 Climax/Ferrari V-12 3.0 in 1963
953	British Racing Partnership	2.5 Climax
954	J. Frank Harrison	2.5 Climax later as Harrison Special-289 Ford
955	Jack Nethercutt	2.5 Climax
956	Charles Vogele	2.5 Climax changed to 2.0 Climax for Hillclimbs
957	Tom Carstens	Empty - 3.5 Buick fitted changed to Chevy V8
958	Roy Schechter	2.5 Climax
959	Peter Ryan	2.5 Climax Engine
960	Robert Publicker	1.5 Climax
961	Dr Harry Zweifel	2.0 Climax for Hillclimbs
962	Rod Carveth	Empty - 3.5 Buick fitted
963	Henry Olds/Bob Colombosian	Empty - 3.5 Buick fitted
964	John Coundley	2.5 Climax
965	Mecom Racing Team	empty - 2.0 Climax fitted changed to 3.5 Buick
966	John Klug	289 Ford

>>Lotus 18

Lotus 18

Lotus 18
Lotus 18 Formula One car
Overview
Manufacturer	Team Lotus
Production	1959-1960
Body and chassis
Class	Formula One, Formula Two, Formula Junior
Body style	Open wheel
Powertrain
Engine	F1: 2467 cc / 2497 cc / 1499.8 cc Coventry Climax FPF F2: 1475 cc Coventry Climax FPF FJ: 998 cc Cosworth Mk.III
Transmission	F1/F2: Lotus (Ansdale-Mundy) sequential 5 speed FJ: Renault 4 speed
Chronology
Predecessor	Lotus 16
Successor	Lotus 20, Lotus 21

The Lotus 18 was a race car designed by Colin Chapman for use by Lotus in Formula Junior, Formula Two, and Formula One.

History
Lotus 18 was the first mid-engined car built by Lotus and was a marked improvement over Chapman's early and only moderately successful front-engined formula cars, the 12 and 16. It was introduced for the 1960 F1, F2 and FJ seasons, and 27 examples are believed to have been made. As a stop-gap before the introduction of the 18's successor models, the Lotus 20 for F2/FJ and 21 for F1, some 18 chassis were rebodied with 21 skins to create the interim Lotus 18/21 hybrid derivative.The 18 was replaced by the Lotus 21 in Formula One and the Lotus 20 in Formula Junior in 1961.

Design

The car was a classic Chapman design, being extremely light and simple; the body was made up of lightweight panels bolted to heavily-triangulated tube frame (almost spaceframe) chassis. Thus the car was rigid, strong and light, maintaining the 16's forward weight distribution despite the engine moving behind the driver.

It was powered initially by a 2,467 cc Coventry Climax FPF (3.70" x 3.50") four cylinder DOHC engine inherited from the Grand Prix version of Lotus 16. In 1960, the FPF was enlarged slightly to 2497 cc (3.70" x 90 mm), which produced 239 hp (178 kW) at 6,750 rpm from a weight of only 290 lbs (132 kg) and had a wide torque range.

The 2.5 litre engine was replaced by a 1.5 Litre (82 mm x 71 mm) Climax FPF Mk.II with new Formula One engine rules in 1961. The Formula Junior variant used a 998 cc Cosworth Mk.III. The Formula Junior version also used smaller gauge chassis tubing and Alfin drum brakes on all four corners.

Further contributing to the weight advantage was the adoption of lightweight sequential manual transmission originally developed for Lotus 12 by Richard Ansdale and Harry Mundy incorporating the unique sequential-shifting gearbox and a ZF limited slip differential in a common Magnesium alloy housing to form a transaxle, which also provided the mounting points for inboard rear brakes. This gearbox had been improved in its reliability for Lotus 15 and 16 in 1957-58 by a Keith Duckworth who had just joined Lotus as a gearbox engineer.

Although Porsche in Austria pioneered the sequentially shifting gearbox for racing cars in Model 360 Cisitalia, the idea was relatively new and the original transaxle in Lotus 12, which was essentially an enlarged motorcycle gearbox combined with ZF limited slip differential, had gained the nickname 'Queer Box', or "Gearbox-full of neutrals" for its poor reliability. With Duckworth having left to form Cosworth in 1958, Mike Costin, who, despite being the co-founder of Cosworth, remained with Lotus for a while longer, adopted the improved Queer Box in Lotus 16 into a configuration for directly mounting it behind the engine for Lotus 18 with dedicated oil scavenge and pressure feed pumps, further improving its reliability while retaining the small and light design.

Formula Junior version utilized the Renault 4 speed transaxle, and both of the Lotus transaxle and this Renault box had the gear shifter lever on the left side of the driver.

The front suspension was by double wishbone arms with outboard coil/damper unit. Unlike Chapman's former designs where the ends of anti-roll bar acted as a leg of the upper wishbone, the 18 had a separate front anti-roll bar. The rear suspension was by upper and lower radius arms with reversed lower wishbone, where the fixed-length halfshaft acted as the upper link. The coil/damper unit was also mounted outboard in the rear, and the 18 sometimes ran with and without the rear anti-roll bar.

In order to capitalize on the weight advantage, Chapman designed a light, sleek machine only 28 inches (71 cm) high (excluding windscreen) and weighing just 980 lbs (440 kg).To help facilitate this, the driver was placed in a semi-reclining position,pioneered about a decade before by Gustav Baumm of NSU.

Race performance

The Lotus 18 had remarkably good handling with a unique suspension system which drastically reduced weight transfer and body roll in cornering. Shortly, the Lotus 18 was proving to be faster than any car Grand Prix racing had ever seen, eclipsing even the legendary Auto Unions and being widely copied. It was also built as a two-seat sports-racer called the Lotus 19 or Monte Carlo.

Grand Prix success

Lotus 18 Formula Junior

The car took Lotus' first F1 victory, by Innes Ireland in the non-championship Glover Trophy, in 8 April 1960. Its first World Championship win happened six weeks later, in 29 May, albeit by privateer Rob Walker, who leased the car from Chapman. Driven by Stirling Moss the car took a dominant win at the 1960 Monaco Grand Prix. It was an early taste of things to come. Moss also won the United States Grand Prix at the end of the season helping Lotus finish second in the constructors' championship.

Moss repeated his win in a legendary race at Monaco the following year, beating off the more powerful and faster 'sharknose' Ferraris. He then won at the fearsome Nürburgring in changeable weather, while Innes Ireland took a third win in the USA to help Lotus finish second in the constructors' championship in 1961. The Lotus 18 was also notable for giving Jim Clark his first Grand Prix start in 1960.

>>Lotus 17

Lotus 17

Lotus 17

The Lotus 17 was a sports car racing model built by Lotus Cars in 1959. Designed by Len Terry, it was built in response to the Lola Mk1 which was dominant against the previous Lotus model, the Eleven. It was replaced in 1960 by the Lotus 19.

The Lotus 17 was Chapman's answer to the Lola Mk 1, which by late 1958, was beating the venerable (but by then a good few years old) Eleven with monotonous regularity. The Lola was smaller and lighter than the Eleven, and so Chapman's riposte was even smaller, even lighter, even more aerodynamic.

It was designed by Len Terry under Chapman's guidance and it incorporated a number of new features, although in fact was the last front-engined sports racing car Lotus made. Its rear suspension was the Chapman strut, first used on the single seat Lotus Twelve, the Elite Coupe and the Lotus 15. Its front suspension was novel for a sport-racing car as it used the MacPherson strut suspension first seen on the Ford Consul in 1952, and was very light. It was Lotus's first glass fibre-bodied sports racing car (although the Works Elevens had fibreglass bodies in 1958), had a very low frontal area and the lightest weight of any multi-seat production Lotus ever made. The declared (albeit dry) weight was 340 kg (17s nowadays struggle to get below a wet 400 kg). It should have been a very effective weapon.

But at its first race in early April 1959, it became apparent that the handling was flawed, with the front struts bending and binding under racing loads. By the time the problem had been identified and rectified by the substitution of the front struts by more conventional wishbones (which was subsequently offered as a factory modification to all owners' 17s), it was all too late and racing had moved on.

So only 21 cars were actually produced. Of these, about a dozen exist today, and it is only now, in modern historic racing where two cars race in Europe and two in the US, that their potential is being realised.

Rear view of Lotus 17

Engine-wise, 17s ran in period with all the small capacity Coventry Climax options, 742 cc FWMA (as in the works 1959 Le Mans entries, which were going very well in class until electrical problems forced their retirement), 1,098 cc FWA (the normal small capacity racing class of the day), 1,216 cc FWE and (in North America) 1460cc. Nowadays, they usually run with the 1,216 cc FWE engine, although the US cars now usually run with the 1460 cc FWB.

>>Lotus 16

Lotus 16

Lotus 16

Category	Formula One/Two
Constructor	Lotus Cars
Designer(s)	Colin Chapman
Successor	Lotus 18
Technical specifications
Chassis	Steel spaceframe.
Suspension (front)	Double wishbone with outboard coilover spring/damper units.
Suspension (rear)	Chapman strut with integrated coilover spring/damper units.
Axle track	1,195 mm (47.0 in)
Wheelbase	2,235 mm (88.0 in)
Engine	Coventry Climax FPF F2: 1,475 cc (90.0 cu in) F1: 1,964 cc (119.9 cu in), 2,207 cc (134.7 cu in), 2,467 cc (150.5 cu in) Gear-driven DOHC, straight-4.Naturally aspirated, front mounted.
Transmission	Lotus (Ansdale-Mundy) 5-speed sequential manual transaxle with ZF differential.
Weight	490 kg (1,080 lb)
Tyres	Dunlop
Competition history
Notable entrants	Team Lotus
Notable drivers	Graham Hill  Innes Ireland
Debut	1958 French Grand Prix
Races Wins Poles Fastest laps 17 0 0 0
Constructors' Championships	0
Drivers' Championships	0
n.b. Unless otherwise stated, all data refer to Formula One World Championship Grands Prix only.

The Lotus 16 was the second single-seat racing car designed by Colin Chapman, and was built by his Lotus Cars manufacturing company for the Team Lotus racing squad. The Lotus 16 was constructed to compete in both the Formula Oneand Formula Two categories, and was the first Lotus car to be constructed for Formula One competition. Its design carried over many technological features of the first Lotus single-seater, the Lotus 12, as well as incorporating ideas which Chapman had been developing while working on the Vanwall racing cars. Indeed, such was the visual similarity between the Vanwall and Lotus 16 designs that the Lotus was often dubbed the "mini Vanwall" by the contemporary motor sport press. Although the Lotus 16 only scored five Formula One World Championship points in the three seasons during which it was used, its raw pace pointed the way for its more successful successors, the Lotus 18 and 21.

Design

Colin Chapman had started building Ford-engined, Austin 7-based specials shortly after the end of World War II, and had quickly graduated to his own sports car designs with the Lotus 6 of 1952. These lithe, lightweight sports cars immediately took a stranglehold on domestic British club racing, and through a rapid succession of upgraded models soon moved up to the international stage, culminating in class wins in the 24 Hours of Le Mans race in both 1956 and 1957. Also in 1956 Chapman's reputation as an engineering innovator saw him drafted in by the ambitious Vanwall team to help develop their Formula One cars, and in 1957 the first single-seat Lotus, the Formula Two Lotus 12, appeared.

A Lotus 16 with its bonnet removed, clearly showing the spaceframe chassis and obliquely aligned engine. Also seen are details of the double wishbone front suspension.

His experiences with Vanwall showed Chapman that his own Lotus 12 design could itself provide the basis for a Formula One competitor. The 12's spaceframe chassis design was adapted to accept its engine in a distinctly offset position and allowed the drive shaft (driven at the engine speed) to pass to the left side of the driver, rather than beneath him, to reach the transaxle located in the rear, lowering the driving position and reducing the frontal area. The steel chassis tubes themselves were of a thinner gauge than the 12's, sacrificing strength in Chapman's quest for weight-saving. However, the handling of the car was badly compromised by the unequal weight distribution which resulted from the engine positioning, and the 16 had to be reworked to accept its engine in a more conventional, albeit obliquely aligned, central location.

The engine itself was Coventry Climax's FPF straight-4, in a variety of sizes. Initially the cars were fitted with the 2 litre powerplant, but as Climax gradually stretched the FPF's capacity the Lotus 16 appeared with a 2.2, then finally a 2.5 litre, full Formula One engine specification. As in the 12, the engine's power was transmitted to the road through the rear wheels, via Lotus's own 5-speed sequential manual transaxle. In its earliest incarnations this transaxle — designed by Richard Ansdale and Harry Mundy incorporating a ZF limited slip differential — proved troublesome and gained itself the derogatorily punning nickname "queerbox". However, in 1957 Chapman had hired Keith Duckworth (later to find fame as one half of the founders of Cosworth, and father of the Cosworth DFV) as a gearbox engineer who made significant improvements to its design. By the time that the Lotus unit found its way into the 16 it was a more reliable and less troublesome system.

The Lotus 16's front suspension was also borrowed from the 12, with Chapman's own double wishbone design incorporating the anti-roll bar within the upper wishbones; an example of Chapman's innovative attention to detail in trying to shave every excess ounce from his cars. Unlike the 12, however, the 16 was designed from the outset to incorporate the Chapman strut rear suspension design. This was one of the first rear independent suspension designs to be incorporated into a Formula One car, and offered much better traction, handling and adjustability than the previously-common de Dion tube systems. The 16 also sported the, by now iconic, Lotus "wobbly-web wheels"; an innovative cast alloy design borrowed from the aviation industry. Brakes were disc brakes all round, mounted inboard at the rear.

That the bodywork enclosing all of Chapman's innovative technology was similar in appearance to the Vanwall Grand Prix cars was no accident, as both cars had been sculpted by pioneer automotive aerodynamacist Frank Costin. As with many of Lotus's competition cars, the aluminium used to construct the bodywork was extremely thin and offered little in the way of support for the underlying chassis members. The car was extremely low and compact, with the bonnet barely reaching the same height as the tops of the front wheels, despite the smaller diameters used from the 1959 season onward. The driver sat in a slightly reclined position — nowhere near as extremely inclined as Chapman would later inflict upon his pilots but still unusual for its day — and behind the driver rose a stubby rear fin, incorporating the fuel tank.

Eight Lotus 16s were built in total.

Competition history

The Lotus 16 had been intended for use from the beginning of the 1958 Formula One season. However, delays owing to the need to reposition the engine within the chassis meant that the first Lotus Formula One car was in fact a converted Lotus 12, which made Lotus's Grand Prix debut at the 1958 Monaco Grand Prix. The Lotus 16 finally saw light of day three Grands Prix later, at the 1958 French Grand Prix on 6 July. A single car was entered for this event, to be driven by works driver and sometime mechanic Graham Hill. The 16 did not perform well, posting the second slowest time in qualifying, only beating team-mate Cliff Allison's 12. Although the 16 was very aerodynamically efficient, thanks to Costin's bodywork, the high speed Reims-Gueux circuit did not favour the 16's rather under-powered 2 litre engine; Hill's car overheated on lap 19.

Lotus 16s were entered for all of the remaining rounds of the 1958 World Championship season, sometimes in Formula Two configuration, but they often failed to finish the race. Commonly this was due to engine overheating or associated failures, but failures of other mechanical systems were far from uncommon. Although Hill and Allison did manage to nurse the 16 to the finish on a few occasions, most often they had completed too few laps to justify an official finishing classification.

For the 1959 Formula One season the works cars were finally upgraded to the full 2.5 litre specification, and mechanical upgrades had been made to improve reliability. In addition to the works team, Lotus 16s had also been sold to a number of privateer entrants. As the season progressed the works cars were gradually developed still further, and their qualifying times began to fall. Reliability was still a major issue, however, and too often the cars failed to complete a full race distance. Although regular works driver Hill failed to finish even a single race during the season, his team-mate Innes Ireland's car held together long enough to take five World Championship points, with fourth place in the Dutch Grand Prix and fifth in the season finale in the United States.

In the opening round of the 1960 Formula One season the works team fielded two 16s for Alan Stacey and local driver Alberto Rodriguez Larreta, while team-leader Ireland was equipped with the new Lotus 18. Following yet another retirement and a non-points finish Team Lotus abandoned the 16 entirely, in favour of the new model. However, with sponsorship from Robert Bodle Ltd., David Piper entered a lone 16 for the 1960 French and British Grands Prix, but again the car failed to trouble the Championship scorers.

World Championship results

Year	Entrant	Engine	Tyres	Drivers	1	2	3	4	5	6	7	8	9	10	11	Pts.	WCC
1958	Team Lotus	Coventry Climax FPF 2.0L L4	D		ARG	MON	NED	500	BEL	FRA	GBR	GER	POR	ITA	MOR	3	6th1
				Hill						Ret	Ret	Ret	Ret	6	16
				Stacey							Ret
				Allison								10
1959	Team Lotus	Coventry Climax FPF 2.5L L4	D		MON	500	NED	FRA	GBR	GER	POR	ITA	USA			5	4th
				Hill	Ret		7	Ret	9	Ret	Ret	Ret
				Lovely	DNQ
				Ireland			4	Ret		Ret	Ret	Ret	5
				Stacey					8				Ret
	John Fisher	Coventry Climax FPF 1.5L L4	D	Halford	Ret
	Dorchester Service Station	Coventry Climax FPF 1.5L L4	D	Piper					Ret
1960	Team Lotus	Coventry Climax FPF 2.5L L4	D		ARG	MON	500	NED	BEL	FRA	GBR	POR	ITA	USA		34	2nd2
				Stacey	Ret
				Rodriguez Larreta	9
	Robert Bodle Ltd.	Coventry Climax FPF 2.5L L4	D	Piper						Ret	12

>>Lotus 15

Lotus 15

Lotus 15
Overview
Manufacturer	Lotus Engineering Ltd.
Production	1958–1960
Designer	Colin Chapman
Body and chassis
Class	Group 4 Sports Car
Body style	Aluminium non-stressed
Layout	Front engine, Rear wheel drive, 2-seater
Powertrain
Engine	Coventry Climax FPF
Transmission	Lotus "Queer Box" 5sp. BMC B-Series 4sp. ZF 5sp.
Dimensions
Wheelbase	88 in (2,235 mm)
Length	140.9 in (3,579 mm)
Width	60 in (1,524 mm)
Height	24 in (610 mm)
Curb weight	992 lb (450 kg)-1,240 lb (562 kg) (dry)
Chronology
Predecessor	Lotus Mk.X
Successor	Lotus 19

The Lotus 15 is a front-engine sports racing car designed by Colin Chapman of Lotus, built from 1958 until 1960.

Series 1

The 15 is a front-engine, rear wheel drive sports racer with an aluminium body over a space frame configuration. As opposed to the six cylinder Bristol 2L engine in its predecessor Lotus Mk.X, the Mk.15 was designed with an all aluminium four cylinder Coventry Climax FPF engine of 1.5 to 2.5 Litre displacement built for Formula Two and Grand Prix racing, mated to Lotus' own 5 speed sequential transaxle nicknamed 'Queer Box'. It was designed in 1957, and the production began in the late 1957.

The spaceframe was similar to Lotus Eleven except for the Chapman strut rear suspension with inboard brakes and the accommodations for a larger engine, which included a slightly (7.5 degrees) tilted engine mounting space on the plan view, shifted to the right of the centerline in the front and left at the rear of the engine. This arrangement gave a larger space for the driver than the normally non-existing passenger.

The larger body (of "English rolled" aluminum) was also similar in appearance to (the smaller) and successful Lotus 11, with a major difference of a full-width windscreen, and the lower scuttle/screen height. Unlike the 11 which was designed by Frank Costin, the body design was a result of the collaboration between Chapman and the coachbuilder Williams & Pritchard.

It was available as a fully assembled form sans the engine at £2885, or as a kit of parts for £2395.

Lotus 15's debut was in Sussex Trophy at Goodwood on April 7th, 1958 in the hands of Graham Hill who immediately set the lap record, but failed to finish the race due to a gearbox problem.

This constant mesh sequential 5 speed gearbox combined with ZF limited-slip differential in the transaxle configuration was compact, light (85lbs including brakes and halfshafts) and quick shifting, but the reliability problem had been carried over from the F1 and F2 Lotus 12 single seater.

Series 2

Colin Chapman hired a young and talented gearbox engineer, Keith Duckworth, to solve this problem, but the priority needed to be on Lotus 16 for Grands Prix, which shared the Queer Box problem, so a newer version Series 2 was born while the update was in development in July, 1958 with BMC B-series four speed gearbox attached directly behind the engine, and a conventional differential housing with brake disc calipers mounted on the sides.

For the purpose of lowering the center of gravity, the Climax engine was tilted about 28 degrees from vertical in the Series 1, but was mounted about 17 degrees from vertical on the Series 2, and a larger bonnet bulge with front air scoop was incorporated on the body to clear the top of the engine.

Series 3

Lotus 15 Series 3. Note the air scoop in the middle of bonnet.

By the time the Series 3 was born in 1959, the Lotus transaxle had become more reliable thanks to the Duckworth redesign on its own dry sump lubrication system, but the young engineer pointed out the inherent limitation of the box in the amount of torque it can safely handle. So the Series 3 was offered with the Lotus 'Queer Box' transaxle for 1.5L FPF only, and BMC 4-speed or ZF 5-speed gearbox with a conventional differential for cars with a larger FPF.

The frame was reinforced in the areas that are deemed to be weak on Series 1 and 2, and the front suspension was upgraded from the previous configuration which had come directly from Lotus 11 Series 2.

Engines

The larger 1.5L engine used for Lotus 11 was a bored and stroked FWB version of Coventry Climax FWA (which was an automotive conversion of a fire pump engine) with a compact SOHC cylinder head. In contrast, the FPF used on Lotus 15 were pure racing engines with a gear-driven DOHC head and dry sump.

1956 FPF 1475cc 4 cyl 3.20 x 2.80" 141 bhp (105 kW)@7300rpm
1957 FPF 1964cc 4 cyl 3.40 x 3.30" 175 bhp (130 kW)@6500rpm
1958 FPF 2207cc 4 cyl 3.50 x 3.50" Smaller block
1958 FPF 2467cc 4 cyl 3.70 x 3.50" 220 bhp (160 kW)@6500rpm Larger block

• The years denote version introduction. For details, see Coventry Climax article.
• Chassis number 15-619 is known to have raced with a Ferrari 500TRC 2L engine in the US in July, 1959.

• Race results

Other drivers beside Graham Hill who drove the 15 in period include Cliff Allison, Roy Salvadori, Jay Chamberlain, Pete Lovely, Innes Ireland, Alan Stacey, Mike Taylor, David Piper,Tim Parnell, David Buxton, Keith Greene, Derek Jolly, John Coombs, Peter Arundell and Chuck Parsons with various levels of success. However, the combination of a Grand Prix engine with the innovative Lotus transaxle generally did not provide a high level of reliability, so the 15 was never crowned with a major endurance title despite the impressive level of speed. It failed to finish the 1958 and 1959 24 Hours of Le Mans.

Production

In total, about 28 Lotus 15 chassis are believed to have been made, including 9 Series 1 and 8 Series 2.