McLaren F1

The McLaren F1's engine compartment contains the mid-mounted BMW S70/2 engine and uses gold foil as a heat shield in the exhaust compartment

Gordon Murray insisted that the engine for this car be naturally aspirated to increase reliability and driver control. Turbochargers and superchargers increase power but they increase complexity and can decrease reliability as well as introduce an additional aspect of latency and loss of feedback. The ability of the driver to maintain maximum control of the engine is thus compromised. Murray initially approached Honda for a power plant rated at 410 kW (550 hp; 557 PS), with 600 mm (23.6 in) of block length and a total weight of 250 kg (551 lb), it was required to be derived from the Formula One power plant in the then-dominating McLaren/Honda cars. When Honda refused, Isuzu, then planning an entry into Formula One, had a 3.5-litre V12 engine being tested in a Lotus chassis. The company was very interested in having the engine fitted into the F1. However, the designers wanted an engine with a proven design and a racing pedigree.[21]

Gordon Murray then approached BMW, which took an interest, and the motorsport division BMW M headed by engine expert Paul Rosche[22] designed and built Murray a 6,064 cc (6.1 L; 370.0 cu in) 60º V12 engine called the BMW S70/2. At 461 kW (618 hp; 627 PS)[23] and 266 kg (586 lb) the BMW engine ended up 14% more powerful and 16 kg (35 lb) heavier than Gordon Murray's original specifications, with the same block length.

It has an aluminium alloy block and heads, with bore x stroke of 86 mm × 87 mm (3.39 in × 3.43 in) DOHC with variable valve timing (a relatively new and unproven technology for the time) for maximum flexibility of control over the 4 valves per cylinder, and a chain drive for the camshafts.

The engine uses a dry sump oil lubrication system. The carbon fibre body panels and monocoque required significant thermal insulation in the engine compartment, so Murray's solution was to line the engine bay with a highly efficient heat-reflector: gold foil. Approximately 16 g (0.56 ounce) of gold was used in each car.[24]

The road version of the engine used a compression ratio of 11:1 to produce a maximum power output of 461 kW (618 hp; 627 PS) at 7,400 rpm and 650 N⋅m (479 lb⋅ft) of torque at 5,600 rpm.[23] The engine's rev limiter is set at 7,500 rpm. In contrast to raw engine power, a car's power-to-weight ratio is a better method of quantifying acceleration performance than the peak output of the vehicle's power plant. The standard F1 achieves 550 hp/ton (403 kW/tonne), or just 0.27 hp/lb.

The cam carriers, covers, oil sump, dry sump, and housings for the camshaft control are made of magnesium castings. The intake control features twelve individual butterfly valves and the exhaust system has four Inconel catalysts with individual Lambda-Sondion controls. The camshafts are continuously variable for increased performance, using a system very closely based on BMW's VANOS variable valve timing system for the BMW M3;[25] it is a hydraulically actuated phasing mechanism which retards the inlet cam relative to the exhaust cam at low revs, which reduces the valve overlap and provides for increased idle stability and increased low-speed torque. At higher rpm the valve overlap is increased by computer control to 42 degrees (compare to 25 degrees on the M3)[25] for increased airflow into the cylinders and thus increased performance.

To allow the fuel to atomise fully, the engine uses two Lucas injectors per cylinder, with the first injector located close to the inlet valve – operating at low engine rpm – while the second is located higher up the inlet tract – operating at higher rpm. The dynamic transition between the two devices is controlled by the ECU.[25] Each cylinder has its own miniature ignition coil. The closed-loop fuel injection is sequential. The engine has no knock sensor as the predicted combustion conditions would not cause this to be a problem. The pistons are forged in aluminium.

Every cylinder bore has a Nikasil coating giving it a high degree of wear resistance.[25] From 1998 to 2000, the Le Mans–winning BMW V12 LMR sports car used a similar S70/2 engine. The engine was given a short development time, causing the BMW design team to use only trusted technology from prior design and implementation experience. The engine does not use titanium valves or connecting rods. Variable intake geometry was considered but rejected on grounds of unnecessary complication.[25] As for fuel consumption, the engine achieves on average 15.2 mpg (15 L/100 km), at worst 9.3 mpg (25 L/100 km) and at best 23.4 mpg (10 L/100 km).[7]

It was later revealed that BMW had used an E34 M5 Touring as a test mule in order to test the engine. The existence of such a test mule was revealed when David Clark, the director of McLaren road and race cars from 1994–1998 disclosed this fact to motoring journalist Chris Harris in a podcast. Clark also revealed that the prototype was kept out of the public eye and that BMW is still in possession of the prototype where it has been kept in their top secret prototype storage facility.[26]

McLaren F1 with all user accessible compartments opened

The McLaren F1 was an early example of a production road car using a complete carbon fibre reinforced polymer (CFRP) monocoque chassis structure. Aluminium and magnesium were used for attachment points for the suspension system, inserted directly into the CFRP.[27]

The car features a central driving position – the driver's seat is located in the middle, ahead of the fuel tank and ahead of the engine, with a passenger seat slightly behind and on each side.[28] The vehicle doors move up and out when opened, and are thus of the butterfly or dihedral type. Gordon Murray's design for the doors was inspired by the Toyota Sera.[29]

The engine produces high temperatures under full application and thus causes a high temperature variation in the engine bay from no operation to normal and full operation. CFRP becomes mechanically stressed over time from high heat transfer effects and thus the engine bay was not constructed from CFRP.[30]

The overall drag coefficient on the standard McLaren F1 is Cd=0.32,[31] compared with Cd=0.36 for the faster Bugatti Veyron, and Cd=0.357 for the SSC Ultimate Aero TT, which was the fastest production car from 2007 to 2010. The vehicle's frontal area is CdA=1.79 square metres (19.3 sq ft) and the S·Cd figure is 0.57. Because the McLaren F1 features active aerodynamics[24][32] these are the figures presented in the most streamlined configuration.

The standard McLaren F1 road car features no fixed wing to produce downforce (compare to the LM and GTR editions); however, the overall design of the underbody of the McLaren F1 in addition to a rear diffuser exploits ground effect to improve downforce which is increased through the use of two electric Kevlar fans to further decrease the pressure under the car.[33] A "high downforce mode" can be turned on and off by the driver.[33] At the top of the vehicle, there is an air intake to direct high pressure air to the engine with a low pressure exit point at the top of the very rear.[33] Under each door is a small air intake to provide cooling for the oil tank and some of the electronics.[33] The airflow created by the electric fans not only increases downforce, but the airflow that is created is further exploited through design, by being directed through the engine bay to provide additional cooling for the engine and the ECU.[33] At the front, there are ducts assisted by a Kevlar electric suction fan for cooling the front brakes.[33]

There is a small dynamic rear spoiler on the tail of the vehicle, which will adjust dynamically and automatically attempt to balance the centre of gravity of the car under braking[24] – which will be shifted forward when the brakes are applied. Upon activation of the spoiler, a high pressure zone is created in front of the flap, and this high pressure zone is exploited—two air intakes are revealed upon application that will allow the high pressure airflow to enter ducts that route air to aid in cooling the rear brakes.[33] The spoiler increases the overall drag coefficient from Cd=0.32 to Cd=0.39 and is activated at speeds equal to or above 40 mph (64 km/h) by brake line pressure.[25]

Steve Randle, who was the car's dynamicist, was appointed responsible for the design of the suspension system of the McLaren F1.[25] It was decided that the ride should be comfortable yet performance-oriented, but not as stiff and low as that of a true track machine, as that would imply a reduction in practical use and comfort as well as increasing noise and vibration, which would be a contradictory design choice in relation to the former set premise – the goal of creating the ultimate road car.

From inception, the design of the F1 had a strong focus on weight distribution by extensive manipulation of placement of, among other things, the engine, fuel and driver, allowing for a low polar moment of inertia in yaw. The F1 has 42% of its weight at the front and 58% at the rear,[25] this figure changes less than 1% with the fuel load.

The distance between the mass centroid of the car and the suspension roll centre was designed to be the same front and rear to avoid unwanted weight transfer effects. Computer controlled dynamic suspension was considered but not applied due to the inherent increase in weight, complexity and loss of predictability of the vehicle.

Damper and spring specifications: 90 mm (3.5 in) bump, 80 mm (3.1 in) rebound with bounce frequency at 1.43 Hz at the front and 1.80 Hz at the rear.[25] Despite being sports oriented, these figures imply a soft ride and inherently decrease track performance. As can be seen from the McLaren F1 LM and the McLaren F1 GTR track variants, the track performance potential is much higher than that in the standard F1 road car due to the fact that the car should be comfortable and usable in everyday conditions.

The suspension is a double wishbone system with an unusual design. Longitudinal wheel compliance is included without loss of wheel control, which allows the wheel to travel backwards when it hits a bump – increasing the comfort of the ride.

Caster wind-off at the front during braking is handled by McLaren's proprietary Ground Plane Shear Centre – the wishbones on either side in the subframe are fixed in rigid plane bearings and connected to the body by four independent bushings which are 25 times more stiff radially than axially.[25] This solution provides for a caster wind-off measured to 1.02 degrees per g of braking deceleration. Compare the Honda NSX at 2.91 degrees per g, the Porsche 928 S at 3.60 degrees per g and the Jaguar XJ6 at 4.30 degrees per g respectively. The difference in toe and camber values is also very small under lateral force application. The Inclined Shear Axis is used at the rear of the machine and provides measurements of 0.04 degrees per g of change in toe-in under braking and 0.08 degrees per g of toe-out under traction.[25]

When developing the suspension system the facility of electro-hydraulic kinematics and compliance at AB Dynamics was employed to measure the performance of the suspension on a Jaguar XJR16, a Porsche 928 S and a Honda NSX to use as references.

Steering knuckles and the top wishbone/bell crank are also specially manufactured in an aluminium alloy. The wishbones are machined from a solid aluminium alloy with CNC machines.[25]

The McLaren F1 uses 235/45ZR17 front tyres and 315/45ZR17 rear tyres. These are specially designed and developed solely for the McLaren F1 by Goodyear and Michelin. The tyres are mounted on 17 by 9 in (431.8 by 228.6 mm) front, and 17 by 11.5 in (431.8 by 292.1 mm) rear five-spoke cast magnesium wheels, coated with a protective paint and secured by magnesium retention pins.[28]

The turning circle from kerb to kerb is 13 m (42.7 ft), allowing the driver 2.8 turns[34] from lock to lock.

The F1 features unassisted, vented and cross-drilled brake discs made by Brembo. The Front size is 332 mm (13.1 in) and the rear 305 mm (12.0 in).[25] The calipers are all four-pot, opposed piston types, and are made of aluminium.[25] The rear brake calipers do not feature any handbrake functionality, however there is a mechanically actuated, fist-type calipers which is computer controlled and thus serve as a handbrake.

To increase caliper stiffness, the calipers are machined from a single solid piece of metal (in contrast to the more common being bolted together from two halves). Pedal travel is slightly over one inch. Activation of the rear spoiler will allow the air pressure generated at the back of the vehicle to force air into the cooling ducts located at either end of the spoiler which become uncovered upon application of it.

Servo-assisted ABS brakes were ruled out as they would imply increased mass, complexity and reduced brake feel; however at the cost of increasing the required skill of the driver.[25]

Gordon Murray attempted to utilise carbon brakes for the F1, but found the technology not mature enough at the time;[30] with one of the major culprits being that of a proportional relationship between brake disc temperature and friction—i.e. stopping power—thus resulting in relatively poor brake performance without an initial warm-up of the brakes before use.[35] Since carbon brakes have a more simplified application envelope in pure racing environments, this allows for the racing edition of the car, the F1 GTR, to feature ceramic carbon brakes.[22]

The standard McLaren F1 has a transverse 6-speed manual gearbox with an AP carbon triple-plate clutch contained in an aluminium housing. The gearbox was developed in collaboration with Weismann transmissions in California.[36] The second generation GTR edition has a magnesium housing.[22] Both the standard edition and the 'McLaren F1 LM' have the following gear ratios: 3.23:1, 2.19:1, 1.71:1, 1.39:1, 1.16:1, 0.93:1, with a final drive of 2.37:1, although the final gear is offset from the side of the clutch. The Torsen Limited Slip Differential has a 40% lock. The sixth gear ratio allows for a longer cruise at 53 km/h (33 mph) per 1000 rpm.[37]

The McLaren F1 has an aluminium flywheel that has only the dimensions and mass absolutely needed to allow the torque from the engine to be transmitted. This is done in order to decrease rotational inertia and increase the responsiveness of the drivetrain, resulting in faster gear changes and better throttle feedback. This is possible due to the F1 engine lacking secondary vibrational couples and featuring a torsional vibration damper by BMW.[25]

1996 McLaren F1 side luggage compartment

Standard equipment for the McLaren F1 includes full cabin air conditioning, a rarity on most sports cars and a system design which Murray again credited to the Honda NSX, a car he had owned and driven himself for 7 years without ever needing to change the AC automatic setting. Further comfort features included SeKurit electric defrost/demist windscreen and side glass, electric window lifts, remote central locking, Kenwood 10-disc CD stereo system, cabin access release for opening panels, cabin storage compartment, four-lamp high performance headlight system, rear fog and reversing lights, courtesy lights in all compartments, map reading lights and a gold-plated Facom titanium tool kit and first aid kit (both stored in the car).[38] In addition, tailored, proprietary luggage bags specially designed to fit the vehicle's carpeted storage compartments, including a tailored golf bag, were standard equipment.[28] Airbags are not present in the car.[7][22] Each customer was given a special edition TAG Heuer 6000 Chronometer wristwatch with its serial number scripted below the centre stem.[39]

All features of the F1 were, according to Gordon Murray, obsessed over, including the interior.[30] The metal plates fitted to improve the aesthetics of the cockpit are claimed to be 20 thousandths of an inch (0.5 mm) thick to save weight.[30] The driver's seat of the McLaren F1 is custom fitted to the specifications desired by the customer for optimal fit and comfort; the seats are handmade from CFRP and covered in light Connolly leather.[28] By design, the F1 steering column cannot be adjusted; however, prior to production each customer specifies the exact preferred position of the steering wheel and thus the steering column is tailored by default to those owner settings. The same holds true for the pedals, which are not adjustable after the car has left the factory, but are tailored to each specific customer.[7]

During its pre-production stage, McLaren commissioned Kenwood, the team's supplier of radio equipment, to create a lightweight car audio system for the car; Kenwood, between 1992 and 1998 used the F1 to promote its products in print advertisements, calendars and brochure covers. Each car's audio system was specially designed to tailor to an individual's listening taste, however radio was omitted because Murray never listened to the radio.

Only 106 cars were manufactured: 5 prototypes (XP1, XP2, XP3, XP4, XP5), 64 road versions (F1), 1 tuned developmental prototype (XP1 LM), 5 tuned versions (LM), 1 longtail developmental prototype (XPGT), 2 longtail versions (GT), and 28 racecars (GTR). Production began in 1989 and ended in 1998.[6] At the time of production, each car took around three and a half months to make.[7]

Although production stopped in 1998, McLaren still maintains an extensive support and service network for the F1. Every standard F1 has a modem which allows customer care to remotely fetch information from the ECU of the car in order to assist the customer in the event of a mechanical vehicle failure.[40] There are eight[41] authorised service centres throughout the world, and McLaren will on occasion fly a specialised technician to the owner of the car or the service centre. All of the technicians have undergone dedicated training in service of the McLaren F1. In cases where major structural damage has occurred, the car can be returned to McLaren directly for repair.[41]

The F1 remains one of the fastest production cars ever made; as of October 2018 it is outmatched by very few cars, including the Bugatti Veyron and the Bugatti Chiron.[42][43]

However, all of the higher top speed machines use forced induction to reach their respective top speeds, whereas the McLaren F1 is naturally aspirated. To date the F1 holds the record for fastest naturally aspirated production car, a record it has held for almost 30 years.

• 0–30 mph (48 km/h): 1.8 s[34]
• 0–40 mph (64 km/h): 2.3 s[34]
• 0–50 mph (80 km/h): 2.7 s[34]
• 0–60 mph (97 km/h): 3.2 s[34]
• 0–70 mph (113 km/h): 3.9 s[34]
• 0–80 mph (129 km/h): 4.5 s[34]
• 0–90 mph (145 km/h): 5.6 s[34]
• 0–100 mph (161 km/h): 6.3 s[34]
• 0–110 mph (177 km/h): 7.2 s[34]
• 0–120 mph (193 km/h): 9.2 s[34]
• 0–124.3 mph (200 km/h): 9.4 s
• 0–130 mph (209 km/h): 10.4 s[34]
• 0–140 mph (225 km/h): 11.2 s[34]
• 0–150 mph (241 km/h): 12.8 s[34]
• 0–160 mph (257 km/h): 14.6 s[34]
• 0–170 mph (274 km/h): 17.2 s[34]
• 0–180 mph (290 km/h): 20.3 s[34]
• 0–190 mph (306 km/h): 23.8 s[34]
• 0–200 mph (322 km/h): 28 s[34]
• 30–50 mph (48–80 km/h): 1.8 s, using 3rd/4th gear[34]
• 30–70 mph (48–113 km/h): 2.1 s, using 3rd/4th gear[34]
• 40–60 mph (64–97 km/h): 2.3 s, using 4th/5th gear[34]
• 50–70 mph (80–113 km/h): 2.8 s, using 5th gear[34]
• 180–200 mph (290–322 km/h): 7.6 s, using 6th gear[34]
• 0–400 m (0.25 mi): 11.045 s at 138 mph (222 km/h)[44]
• 0–1,000 m (0.62 mi): 19.548 s at 276.41 km/h (171.75 mph)[44]

• 30–0 mph (48–0 km/h): 9.7 m / 31.83 ft[45]
• 50–0 mph (80–0 km/h): 25.2 m / 82.68 ft[45]
• 70–0 mph (112–0 km/h): 49 m / 162 ft[34]
• Skidpad Lateral Acceleration: 1.2–1.3g[21]

• Tsukuba Circuit, time trial: 1:04.62 (Driven by Naoki Hattori in Best Motoring) on a hot lap with humid (92%) weather and some mis-shifting.[46]
• Millbrook Proving Ground in Bedfordshire, 2-mile (3.2 km) banked circuit, top speed test: An average speed of 195.3 mph (314.3 km/h), with a maximum speed of 200.8 mph (323.2 km/h) (driven by Tiff Needell using the XP5 prototype).[47]
• MIRA Proving Ground, 2.82-mile (4.54 km) banked circuit, top speed test: An average speed of 168 mph (270 km/h), with a maximum speed of 196.2 mph (315.8 km/h) (driven by Peter Taylor).[47]
• Bedford Autodrome West Circuit Post 2006 Hot Lap: 1:21.20 done by Evo magazine with a custom modified McLaren F1 (with the same tyres as the Enzo) on 10 January 2007 which was faster than the Ferrari Enzo lap time of 1:21.30[48]
• Estoril circuit lap is 1:55.9 in 1994 (4.36 km) configuration of the track with 3 people on board in July 1994.[49][50]
• The 1st lap of Nurburgring was completed by Jonathan Palmer in the XP4 prototype, where he reached a maximum of 200 mph (322 km/h) on the track.[51]

A 1995-spec F1 GTR, chassis #006R at the Goodwood Festival of Speed sporting the famous 'Harrods' livery

Built at the request of race teams, such as those owned by Ray Bellm and Thomas Bscher, in order to compete in the BPR Global GT Series, the McLaren F1 GTR was a custom-built race car which introduced a modified engine management system that increased power output – however, air-restrictors mandated by racing regulations reduced the power back to 441 kW (591 hp; 600 PS) at 7,500 rpm.[57] The car's list of modifications included changes to body panels, suspension, aerodynamics and the interior. The F1 GTR would go on to take its greatest achievement with first, third, fourth, fifth, and 13th places in the 1995 24 Hours of Le Mans, beating out custom built prototype sports cars. When Mark Blundell – who finished fourth in the race – was asked what the F1 GTR was like to drive during the wet race, he said: "Well it was never designed to be a race car so in many respects it wasn't the best-balanced car in the world. The saving grace of the car was the BMW V12 engine. It was incredibly impressive in that you could be in 6th gear at 2,000 rpm and the thing would just pull like a train. And in the wet that is great as you can run a higher gear and it cuts out some of that traction issue. But in terms of balance, overall it was always a bit top heavy, so the centre of gravity wasn’t ideal. And aerodynamically it wasn't quite there, but it did the job".[58]

In total, nine F1 GTRs were built for the 1995 season.[57]

The 1995 F1 GTR created so much downforce that it was claimed to be able to drive upside down along a ceiling at 100 mph (161 km/h).[59]

A 1996-spec F1 GTR, chassis #015R at the Brands Hatch circuit

To follow up on the success of the F1 GTR in 1996, McLaren further developed the 1995 model, leading to a size increase but a weight decrease. Nine more F1 GTRs were built to 1996 spec, while some 1995 cars were still campaigned by privateers. F1 GTR 1996 chassis #14R is notable as being the first non-Japanese car to win a race in the All-Japan Grand Touring Car Championship (JGTC).[60] The car was driven by David Brabham and John Nielsen. The weight was reduced to around 37 kg (82 lb) from the 1995 GTR but the engine was kept de-tuned at 447 kW (599 hp; 608 PS) to comply with racing regulations.[61]

A 1997-spec F1 GTR "Long Tail", chassis #027R of Parabolica Motorsports during an FIA GT Championship event

With three F1 GT homologation street versions produced, McLaren could now develop the F1 GTR for the 1997 season. Weight was further reduced and a sequential gearbox was added. The engine was slightly destroked to 6.0 L instead of the previous 6.1 L. Due to the heavily modified bodywork, the F1 GTR 1997 is often referred to as the "Longtail" thanks to the rear bodywork being extended to increase downforce. A total of ten F1 GTRs were built for the 1997 season. The weight was reduced to a total of 910 kg (2,006 lb).

McLaren XP3 prototype, photographed during testing in 1993. The car was owned by Gordon Murray.

Notice the fog lights integrated in the front bumper and narrower turn signals than the production version along with the wing mirrors sourced from a Citroën CX. The fog lights were removed and the wing mirrors were later replaced by production units.

A McLaren F1 with the wing mirrors mounted on the A-pillar as on the prototypes

Prior to the sale of the first McLaren F1s, five prototypes were built, carrying the numbers XP1 through XP5.[62] These cars carried minor subtle differences between each other as well as between the production road cars. Contrary to common misunderstanding, XP1, the first ever running prototype, was never publicly unveiled. The XP1 was never painted (with a bare carbon fibre exterior) and was later destroyed in an accident in Namibia. The car unveiled at the Monaco 1992 event was actually a "Clinic Model", aesthetically convincing but without a powertrain. XP2 was used for crash testing (sporting a blue colour during the test) and also destroyed. As it was a crash test car, it didn't have full interior equipment or a powertrain. XP3 did durability testing, XP4 stress tested the gearbox system and XP5 was a publicity car. The XP3 used to be owned by Gordon Murray before being sold to a private buyer.[63] XP4 was seen by viewers of Top Gear when reviewed by Tiff Needell in the mid-1990s and later on sold to a private owner, while XP5 went on to be used in McLaren's famous top speed run and is still owned by McLaren.

Seven McLaren F1s were imported by Ameritech and modified in order to be federalized for road use in the United States. These modifications include the deletion of side seats, the replacement of headlights, a heightened bumper and dampened performance figures including handling and braking compared to the European F1, due to road legality issues. It weighs in at 1,288.2 kg (2,840 lb).

Performance figures as tested by Road And Track Magazine in 1997:[64]

Performance figures are lower than a regular F1 in all aspects (apart from 0–30 mph (0–48 km/h)) relating to performance. As Mario Andretti noted in a top speed comparison test after hitting the rev limiter at 217.7 mph (350.4 km/h) on Ameritech F1, the Ameritech F1 is fully capable of pulling a seventh gear, thus with a higher gear ratio or a seventh gear the car would probably be able to reach an even greater top speed.[65]

• 0–30 mph: 1.7 seconds[64]
• 0–40 mph: 2.3 seconds[64]
• 0–50 mph: 2.9 seconds[64]
• 0–60 mph: 3.4 seconds[64]
• 0–70 mph: 4.5 seconds[64]
• 0–80 mph: 5.3 seconds[64]
• 0–90 mph: 6.1 seconds[64]
• 0–100 mph: 7.7 seconds[64]
• 0–110 mph: 8.8 seconds[64]
• 0–120 mph: 10.5 seconds[64]
• 1/4 mile: 11.6 seconds at 125 mph[64]
• 0–100 ft at 2.7 seconds[64]
• 0–500 ft at 6.5 seconds[64]
• Top Speed: 217.7 mph[65]

• 60–0 mph: 127 ft[64]
• 80–0 mph: 215 ft[64]

• Skidpad 200 ft: 0.86g[64]
• Slalom 700 ft Speed: 64.5 mph[64]

The McLaren F1 XP1 LM prototype on display

The McLaren F1 LM (LM for Le Mans) is a series of five special cars which were built in honour of the five McLaren F1 GTRs which finished the 1995 24 Hours of Le Mans, including the winning car.[66]

The weight was reduced by approximately 76 kg (167.6 lb) to a total of 1,062 kg (2,341 lb) – achieved by having no interior noise suppression, no audio system, a stripped-down base interior, no fan-assisted ground effect and no dynamic rear wing. The car also had a different transaxle, various aerodynamic modifications, specially designed 18 in (457.2 mm) magnesium alloy wheels and an upgraded gearbox. The F1 LM used the same engine as the 1995 F1 GTR, but without race-mandated restrictors, to produce 500 kW (671 hp; 680 PS). It had a top speed of 225 mph (362 km/h), which is less than the standard version because of added aerodynamic drag, despite identical gear ratios. In the place of the small dynamic rear wing there is a considerably larger, fixed CFRP rear wing mounted on the back of the vehicle.

The LM has the following specifications:

• Peak torque of 705 N⋅m (520 lbf⋅ft) at 4,500 rpm
• Peak power of 500 kW (671 hp; 680 PS) at 7,800 rpm
• A redline at 8,500 rpm
• Total weight of 1,062 kg (2,341 lb) which gives the car an 82.15 kW (110 hp; 112 PS) per litre ratio.[67]

While McLaren has never claimed specific acceleration figures for the LM, Motor Trend recorded traction-limited times of 0–60 mph in 3.9 seconds and 0–100 mph in 6.7 seconds.[59] The LM was once the holder of the 0–100–0 mph record, which it completed in 11.5 seconds when driven by Andy Wallace at the disused airbase RAF Alconbury in Cambridgeshire.[68]

The F1 LMs can be identified by their Papaya Orange paint. They were painted in this colour in memory of, and tribute to, Bruce McLaren, whose race colour was Papaya Orange. Two of the chassis were painted in Black with Grey trim similar to the Ueno Clinic sponsored Le Mans 24 Hours winning car. These cars were bought by the Sultan of Brunei and, as such, also feature horizontal stripes down the sides in yellow, red and blue.[69]

Although only five F1 LMs were sold, a sixth chassis exists in the form of XP1 LM, the prototype for modifications to the existing F1 to form the new F1 LM. This car is also painted Papaya Orange and is retained by McLaren.

McLaren F1 HDK chassis number 14

Two standard F1s were upgraded to "LM specification". These have chassis numbers 073 and 018. The engines were upgraded to unrestricted GTR specification resulting in a power output of 500 kW (671 hp; 680 PS) and had the High Downforce Kit (HDK) added to them. Their interiors were made more comfortable over the F1 LM. The car having chassis number 018 had upgrades to the air conditioning units, the headlamps changed to a gas discharge type and the steering wheel changed to a 14-inch unit. Moreover, race specification dampers and springs set to the softest settings for comfortable road use were added. 18-inch GTR wheels were used instead of the standard 17-inch and the tyres used are Michelin Pilot Sport units.[70][71]

McLaren F1 GT
The McLaren F1 GT developmental prototype (chassis #056XP) at the 2015 Geneva Motor Show
Overview
Manufacturer	McLaren Cars
Production	1997 3 produced (2 production cars and 1 developmental prototype)
Assembly	Woking, England, UK
Designer	Gordon Murray Peter Stevens Paul Rosche (engine designer) (BMW)
Body and chassis
Class	Sports car (S)
Body style	2-door coupé
Layout	Rear mid-engine, rear-wheel-drive
Platform	McLaren F1
Related	McLaren F1 GTR
Powertrain
Engine	6.1 L BMW S70/2 V12
Transmission	6-speed manual
Dimensions
Wheelbase	2,718 mm (107.0 in)[72]
Length	4,928 mm (194.0 in)[72]
Width	1,940 mm (76.4 in)[72]
Height	1,200 mm (47.2 in)[72]
Kerb weight	1,120 kg (2,469 lb)[72]

The final and rarest incarnation of the road car, the F1 GT was meant as a homologation special. With increased competition from homologated sports cars from Porsche and Mercedes-Benz in the former BPR Global GT Series and the new FIA GT Championship, McLaren required extensive modification to the F1 GTR in order to remain competitive. These modifications were so vast that McLaren would be required to build a production road-legal car on which the new race cars would be based.

The F1 GT featured the same extended rear bodywork as the GTRs for increased downforce and reduced drag, yet lacked the rear wing that had been seen on the F1 LM.[73] The downforce generated by the longer tail was found to be sufficient to not require the wing. The front end was also similar to the racing car, with extra louvers and the wheel arches widened to fit larger wheels. The interior was modified and a racing steering wheel was included in place of the standard unit.

The F1 GTs were built from standard F1 road car chassis, retaining their production numbers. The developmental prototype GT, known as XPGT, was F1 chassis #056XP, was painted dark green ("Silverstone green") and is owned by a private collector in Switzerland. The company technically only needed to build one car and did not even have to sell it. However, demand from customers drove McLaren to build two production versions that were sold- the customer F1 GTs were chassis #054 and #058. #054 was painted black and is owned by the Sultan of Brunei Hassanal Bolkiah, while #058 was painted burgundy and is owned by the ZAZ Museum in Japan.[74] It weighs 1,120 kg (2,469 lb), 20 kg (44 lb) lighter than the standard F1 and has a top speed of over 240 mph (386 km/h), although this was never tested.