McLaren F1 GTR, 1995

McLaren F1 GTR, 1995

 

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 600 hp (447 kW) at 7500 RPM. The cars extensive modifications included changes to body panels, suspension, aerodynamics and the interior. The McLaren F1 GTR would go on to take its greatest achievement with 1st, 3rd, 4th, 5th, and 13th places in the 1995 24 Hours of Le Mans, beating out custom built prototype sports cars.

In total, nine McLaren F1 GTRs would be built for 1995.

McLaren F1 GTR '96
To follow up on the success of the McLaren F1 GTR into 1996, McLaren further developed the '95 model, leading to a size increase but weight decrease. Nine more F1 GTRs were built to 1996 spec, while some 1995 cars were still campaigned by privateers. McLaren F1 GTR '96 chassis #14R is notable as being the first non-Japanese car to win a race in the All-Japan Grand Touring Car Championship (JGTC). The car was driven by David Brabham and John Nielsen. The weight was reduced with around 100 kg from the 1995 GTR edition and the engine was kept detuned at 600 HP to comply with racing regulations.

McLaren F1 GTR '97
With the F1 GT homologated, McLaren could now develop the McLaren F1 GTR for the 1997 season. Weight was further reduced and a sequential transaxle was added. The engine was slightly destroked to 6.0L instead of the previous 6.1L. Due to the heavily modified bodywork, the McLaren F1 GTR '97 is often referred to as the "Longtail" thanks to the rear bodywork being extended to increase rear downforce. A total of ten McLaren F1 GTR '97s were built. The weight was reduced to a total of 910 kg.

McLaren F1, 1993

McLaren F1, 1993

 

 

 The McLaren F1 is a sports car designed and manufactured by Gordon Murray and McLaren Automotive. On March 31, 1998, it set the record for the fastest production car in the world, 240 mph (391 km/h). As of April 2009, the McLaren F1 is succeeded by three faster cars in sheer top speed, but is still the fastest naturally aspirated production car.

The car features numerous proprietary designs and technologies. It is lighter and has a more streamlined structure than even most of its modern rivals and competitors despite having one seat more than most similar sports cars, with the driver's seat located in the middle. It features a powerful engine and is somewhat track oriented, but not to the degree that it compromises everyday usability and comfort. It was conceived as an exercise in creating what its designers hoped would be considered the ultimate road car. Despite not having been designed as a track machine, a modified race car edition of the vehicle won several races, including the 24 Hours of Le Mans in 1995, where it faced purpose-built prototype race cars. Production began in 1992 and ended in 1998. In all, 106 cars were manufactured, with some variations in the design.

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 McLaren F1 was the first production car to use a carbon-fibre monocoque chassis.

The idea was first conceived when Murray was waiting for a flight home from the fateful Italian Grand Prix in 1988; Murray drew a sketch of a three seater sports car 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.

Engine
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 One powerplant in the then-dominating McLaren/Honda cars.

When Honda refused, Isuzu, then planning an entry into Formula One, had a 3.5 V12 engine being tested in a Lotus chassis. The company was very interested in having the engine fitted into the McLaren F1. However, the designers wanted an engine with a proven design and a racing pedigree.

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. The bespoke engineered engine for the McLaren F1 is called the BMW S70/2.

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 11:1 to produce 627 hp (468 kW; 636 PS) 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 redline rev limiter set at 7500 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 powerplant. The standard McLaren F1 achieves 550 hp/ton (403 kW/tonne), or just 3.6 lb/hp. Compare with the Ferrari Enzo at 434 hp/ton (314 kW/tonne) (4.6 lb/hp), the Bugatti Veyron at 530.2 hp/ton (395 kW/tonne) (4.1 lb/hp), and the SSC Ultimate Aero TT with an alleged 1003 hp/ton (747.9 kW/tonne) (2 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-Sond 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.

Every cylinder bore has a nikasil coating giving it a high degree of wear resistance.
From 1998 to 2000, the Le Mans-winning BMW V12 LMR sports car used a similar S70/2 engine.

McLaren M6GT, 1969

McLaren M6GT, 1969

The McLaren M6A was a racing car developed by driver Bruce McLaren and his Bruce McLaren Motor Racing team for their entry in 1967 Can-Am season. As a replacement for the team's M1Bs from 1966, the Chevrolet-powered McLaren M6A's improved design earned Bruce McLaren and his team their first of multiple Can-Am championships. After the McLaren M6A were replaced by the M8A in preparation for 1968, McLaren and technical partner Trojan developed the M6B which was sold to customers for use in Can-Am as well as other racing series.

The M6 name was later used in the development of a closed-cockpit sports car for the 24 Hours of Le Mans and known as the M6GT. The company's plan to homologate it for the FIA's Group 4 regulations was however never completed, and only a few M6GT prototypes were finished by McLaren and Trojan. Two M6GTs were later converted to road cars, one of which became Bruce McLaren's personal transport.

Development
Bruce McLaren gathered several designers to develop the McLaren M6A during the off-season in early 1967. Along with McLaren himself, Robin Herd, Gordon Coppuck, Tyler Alexander, and Don Beresford all worked on the layout of the McLaren M6A's chassis and bodywork. The car featured the first monocoque chassis constructed by McLaren, while the bodywork was specifically shaped to increase downforce suited for the Can-Am circuits. McLaren's team also expanded into engine development, creating a fuel injection system for their Chevrolet V8s. Another addition to the team was a new tire supplier, with Goodyear replacing Firestone in exchange for a testing and development program.

The first McLaren M6A was completed in spring 1967, and brought to the nearby Goodwood Circuit for testing. Bruce McLaren Motor Racing carried out over 2000 miles of testing at the circuit in preparation for the upcoming Can-Am season, tuning the car as well as gathering data for Goodyear's use. As two further McLaren M6A were completed, the team shipped the cars to North America to prepare for the opening race of the season. A final addition to the cars was a coat of orange paint. This new McLaren Orange color scheme would eventually become synonymous with Bruce McLaren and the team.

After the retirement of the McLaren M6A, McLaren entrusted Trojan with constructing duplicates which could be sold to customers. These M6Bs were nearly identical to the McLaren M6A but were sold without an engine. Several other M6Bs were also modified to fit closed-cockpit bodywork.

Racing history
The 1967 Can-Am season began in September at Road America. Bruce McLaren's M6A qualified on pole position with a new track record, while teammate Denny Hulme's car led once the race began. Although McLaren's car suffered an oil leak and failed to finish, Hulme was able to earn the car's first victory. The next two events had the team running away from the opposition, with Hulme and McLaren finishing first and second consecutively. The roles were however swapped over the next two races as it was McLaren who won on both occasions, but problems with Hulme's car allowed McLaren to take the lead in the points standings going into the final round. For the finale at the Stardust Grand Prix, problems with the Chevrolet motors led to blown engines and neither car reaching the finish. However, with their performance over the season, Bruce McLaren secured the 1967 Can-Am Challenge Cup, while Hulme was ranked second only three points behind.

As Bruce McLaren Motor Racing moved to developing the M8A, the M6Bs began to be delivered to customers for the 1968 season. Several of the McLaren M6A were also sold with Roger Penske purchasing one car for defending United States Road Racing Championship (USRRC) champion Mark Donohue. Donohue won several USRRC events that season and earned his second championship. Donohue also later won a race in Can-Am, beating the newer McLaren M8As. After the cancellation of the USRRC after 1968, the M6As and M6Bs continued to be used into the early 1970s but none were able to achieve victory against their newer competitors.