McLaren F1 vs 3 Mercedes Sports Cars
The McLaren F1 was formerly the fastest street legal production car in the world, holding this record from 1994 to 2005, the longest period the record has been held by any street legal or production car in the history of automobiles. It was engineered and produced by McLaren Automotive, a subsidiary of the British McLaren Group that, among others, owns the McLaren Mercedes Formula One team. Today, it is still the fastest naturally aspirated car in the world.
Fifth Gear - Ferrari Enzo vs McLaren F1
The car features a 6.1-litre 60° BMW S70 V12 engine and it was conceived as an exercise in creating what its designers hoped would be considered the ultimate road car. Only 107 cars were manufactured, 64 of those were street versions (F1), 5 were LMs, 3 were longtail roadcars (GT), 5 prototypes (XP), 28 racecars (GTR), and 1 LM prototype (XP LM). Production began in 1992 and ended in 1998.
The McLaren F1 was at the time the fastest production car ever built, eclipsing the Jaguar XJ220. A standard version of the McLaren achieved a top speed of 371 km/h (231 mph) in 1994, holding this record for more than 10 years until it was finally eclipsed in 2005 by the Koenigsegg CCR.
Design and implementation
Chief engineer Gordon Murray's design concept was a common one among designers of high-performance cars: low weight and high power. This was achieved through use of high-tech and expensive materials like carbon fibre, titanium, gold, magnesium and kevlar. The F1 was one of the first production cars to use a carbon-fibre monocoque.
The idea was first conceived when Murray was waiting for a flight home back from the fateful Italian Grand Prix in 1988; Murray drew a sketch of a three seater supercar and proposed it to Ron Dennis, pitched as the idea of creating the ultimate road car, a concept that would be heavily influenced by the Formula One experience and technology of the company and thus reflect that skill and knowledge through the Mclaren F1.
Quote from Gordon: "During this time, we were able to visit with Ayrton Senna (the late F1 Champion) and Honda's Tochigi Research Center. The visit related to the fact that at the time, McLaren's F1 Grand Prix cars were using Honda engines. Although it's true I had thought it would have been better to put a larger engine, the moment I drove the Honda NSX, all the benchmark cars—Ferrari, Porsche, Lamborghini—I had been using as references in the development of my car vanished from my mind. Of course the car we would create, the McLaren F1, needed to be faster than the NSX, but the NSX's ride quality and handling would become our new design target. Being a fan of Honda engines, I later went to Honda's Tochigi Research Center on two occasions and requested that they consider building for the McLaren F1 a 4.5 liter V10 or V12. I asked, I tried to persuade them, but in the end could not convince them to do it, and the McLaren F1 ended up equipped with a BMW engine."
Later, a pair of Ultima MK3 kit cars, chassis numbers 12 and 13, "Albert" and "Edward", the last two MK3s, were used as "mules" to test various components and concepts before the first cars were built. Number 12 was used to test the gearbox with a 7.4 litre Chevrolet V8 to mimic the torque of the BMW V12, plus various other components like the seats and the brakes. Number 13 was the test of the V12, plus exhaust and cooling system. When McLaren was done with the cars they destroyed both of them to keep away the specialist magazines and because they did not want the car to be associated with "kit cars".
The car was first unveiled at a launch show, 28 May 1991, at The Sporting Club in Monaco. The production version remained the same as the original prototype (XP1) except for the wing mirror which, on the XP1, was mounted at the top of the A-pillar. This car was deemed not road legal as it had no indicators at the front; McLaren was forced to make changes on the car as a result (some cars, including Ralph Lauren's, were sent back to McLaren and fitted with the prototype mirrors). The original wing mirrors also incorporated a pair of indicators which other car manufacturers would adopt several years later.
The car's safety levels were first proved when during a testing in Namibia in April 1993, a test driver wearing just shorts and t-shirt hit a rock and rolled the first prototype car several times. The driver managed to escape unscathed. Later in the year, the second prototype (XP2) was especially built for crashtesting and passed with the front wheel arch untouched.
History
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 introducing an additional aspect of latency and loss of feedback, the ability of the driver to maintain maximum control of the engine is thus decreased. Murray initially approached Honda for an NA powerplant with 550 bhp (410 kW/560 PS), 600 mm (23.6 in) block length and a total weight of 250 kg (551 lb), it should be derived from the Formula 1 powerplant in the then-dominating McLaren/Honda cars.
When Honda refused, Isuzu, then planning an entry into Formula 1, had a 3.5 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.
In the end BMW took an interest, and the motorsport division BMW M headed by engine expert Paul Rosche designed and built Murray a custom-designed 6.1 L (6064 cc) 60-degree V12 engine, which was 14% more powerful than specified and 16 kg (35 lb) heavier – despite being based on the original specifications of 550 bhp (410 kW/560 PS), 600 mm (23.6 in) block length and total weight of 250 kilograms (550 lb).
Specifications
The final result is a custom-built 6.1 L (6064 cc) 60-degree V12 with an aluminium alloy block and head, 86 mm (3.4 in) x 87 mm (3.4 in) bore/stroke, quad overhead camshafts for maximum flexibility of control over the four valves per cylinder and a chain drive for the camshafts for maximum reliability, the engine is dry sump. At 266 kg (586 lb), the resulting engine was slightly heavier than Murray's original maximum specification weight of 250 kg (551 lb) but was also considerably more powerful than he had specified. A common misconception is that the engine was based on BMW's existing production 12-cylinder offering, the slow-revving and heavy M70/S2 engine used in its 7- and 8-series production cars. But in fact, the engine BMW provided to McLaren was a custom design, closer in concept to two 6-cylinder E36 M3 engines on a common block.
The carbon fibre body panels and monocoque required significant heat insulation in the engine compartment, so Murray's solution was to line the engine bay with a highly efficient heat-reflector: gold foil. Approximately 25 g (0.8 ounce) of gold was used in each car.
The road version used a compression ratio of 10.5:1 to produce 627 brake horsepower (467 kW) at 7400 rpm—considerably more than Murray's specification of 550 horsepower (404 kW). Torque output of 480 ft·lb (651 N·m) at 5600 rpm. The engine has a red line and rev limiter set at 7500 rpm. Other, more highly tuned, incarnations of the F1 produced up to 691 bhp at 7500 rpm and 735 Nm of torque (updated LM engine), making a significant performance improvement. There is only one other McLaren F1 roadcar with this engine.
In contrast to raw engine power, a car's power-to-weight ratio is a better method of quantifying performance than the peak output of the vehicle's powerplant. The standard F1 achieves 550 hp/ton (403 kW/tonne), or just 3.6 lb/hp. Compare with the Enzo Ferrari at 434 hp/ton (314 kW/tonne) (4.6 lb/hp), the SSC Ultimate Aero TT with 1003 hp/ton (747.9 kW/tonne) (2 lb/hp), and the Bugatti Veyron at 530.2 hp/ton (395 kW/tonne) (5.1 lb/hp).
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-Sound controls. The camshafts are continuously variable for increased performance, using a system very closely based on BMW's VANOS variable timing system for the BMW M3; 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 25 degrees on the M3) 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 engine computer.
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.
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.
Replicas and Models
Kit car builder DDR Motorsport builds a kit that resembles the F1, based on the Toyota MR-2 SW20 Turbo.
Certain die-cast scale models of the F1 are now extremely desirable among collectors. Most of these models are now out of production. Manufacturers of McLaren F1 models include UT Models, Maisto, Minichamps/Paul's Model Art, Guiloy and Autobarn. Models have been produced in 1:87, 1:64, 1:43, 1:24, 1:18 and 1:12. Among the most desirable of these models are the Minichamps 1:43 McLaren F1 GTR West Promotion model (which can sell for 1,000 dollars). And the UT Models 1:18 silver & dark blue McLaren F1 LMs (which each can sell for over US$400 at auction).
