Friday, 2 November 2012
McLaren M6GT prototype
Bruce McLaren planned a road car before his death in 1970. A prototype M6GT was close to racing engineering but never reached production. McLaren came to England in 1958, joining the Cooper works Formula 1 team as number two driver to Jack Brabham, and with victory in the United States GP at Sebring in 1959, aged 22 years and 104 days became the youngest driver to win a Grand Prix*. McLaren finished second in the 1960 world championship, and came third in 1962, but the Coopers' intuitive engineering couldn’t keep up, and by 1965 McLaren had set up on his own. Bruce McLaren Motor Racing was in Formula 1 and also big-engined sports cars racing for the Canadian-American Challenge Cup.
The big orange 2-seaters dominated Can-Am. Bruce and fellow New Zealander Denny Hulme shared the championship from 1967 to 1969, Hulme carrying on following McLaren's death. The team's progress in Formula 1 showed prescience in materials and techniques; the 1966 cars well ahead of their time with hulls made of composites, later commonplace.
A sort of road-going Can-Am car was a sound practical proposition. Its close relationship with the racing cars would have encouraged sales throughout North America where McLarens so eclipsed all opposition. Trojan, an old established British company, made 26 of the sports-racers under licence essentially for McLaren competitors, so it was a logical step to base a road car on this racing M6A.
Plans to homologate it with a closed coupe body, known as the M6GT, for Le Mans-style endurance racing led to a prototype, with the option of a Ford or Chevrolet V8. McLaren was confident 250 cars a year would enable him to compete for sales with Ferrari, Maserati and newly established Lamborghini.
Design broadly conformed to Bruce's theory that if suspension pickup points and engine were always in roughly the same place relative to one another, the metal joining them up could be pretty well any shape. Thus a single-seater, or a 2-seater, or a coupe such as the M6GT followed a pattern and all handled well. The M6GT monocoque was formed, like the racing cars, from aluminium alloy panelling, bonded and rivetted to steel bulkheads, with two 25-gal flexible aircraft-type safety fuel tanks, in the side pontoons.
Problems arose. As little more than a racing car with a pretty, closed glass-reinforced plastic body, the radiator outlet duct on the nose threw up heat and noise that might have been acceptable in a racing car, but could not be tolerated even on an overtly sporting car. Wide body sills made getting in and out difficult, and although odd-sized wheels front and rear made an important contribution to handling and roadholding, spare wheel stowage was problematical. Eoin Young, McLaren's secretary, described the M6GT as "bliss" to ride or drive in. "Even with a standard 5litre Chevrolet V8 in the back it would accelerate to 100mph in around 8sec, and the handling was fantastic. One problem was that the car was so low that other traffic had difficulty seeing it. Bruce loved the GT."
Co-designer Gordon Coppuck, also responsible for McLaren race cars noted, "I was really surprised how comfortable the car was. Quite incredible when you considered that it was basically a racing car. Unfortunately it was extremely noisy; I had to wear ear muffs when I was testing it."
Less than 2,000 miles of evaluation had been completed before Bruce McLaren died at Goodwood on 2nd June, 1970, at the age of 32. Phil Kerr, a director of McLaren Racing said: "Bruce had done so much at an age when Colin Chapman and Jack Brabham were only at the beginning of their careers, it is difficult to know how much he might have achieved in later life."
The M6GT showed McLaren had the talent and ambition to become a constructor as distinguished as Ferrari. During negotiations to homologate the car for Group 4, Specialised Mouldings created the body style and laid down moulds for 50 to meet Fédération Internationale de l'Automobile (FIA) requirements. It was largely as a result of the FIA's refusal to grant homologation, that McLaren and Phil Kerr decided to use up components already on order, to create the road car.
Denny Hulme tested the M6GT at Goodwood, and lapped in 1min 14sec when his Can-Am racer was doing 1min 10sec. The racer was doing 180mph on the straight, and the GT 165mph with a moderately tuned Chevrolet engine.
When McLaren died McLaren Racing had its hands full getting over the tragedy, pulling itself together merely to survive. The project languished. Trojan used one of the spare bodies to make another one in the early 1970s, and it was eventually disposed of in the United States where it met with an accident.
Another was sold to David Prophet, who raced it in Britain, while a third built in the 1970s, based on a Trojan-made M6B tub went to a collection in Germany. Yet another passed to Phil Kerr and Denny Hulme, was flown to New Zealand and placed on exhibition until 1986, when Kerr and Hulme had it stripped down and rebuilt to remain essentially as it was when one of the most notable driver-constructors of the modern era stepped out of it at the height of his career, and at the start of its development.
Chassis number: BMR M6GT-1
Specification: Engine, Chevrolet Corvette LT1, bore 4.00in
101.6 mm, stroke 3.48in 88.39mm, 350 cu in 5,740cc in; 11:1 compression; carburettor: four-barrel Holley; 370bhp at 6,000rpm. Transmission: ZF Type 25, 5 speed 5DS-26 No:209 Chassis: Monocoque with aluminum panelling bonded and rivetted to steel bulkheads. Suspension: Unequal length upper and lower wishbones, anti-roll bar, and coil-spring shock absorber units at the front. At the back, wishbones and twin radius arms, anti-roll bar and coil spring shock absorber units. Brakes: Girling ventilated discs 12in diamater with 16-3-LA calipers and duel hydraulic circuits. Body: Reinforced polyester resin panelling. Wheels: 15 x 10.5 front 15 x 14 rear cast magnesium. Tyres: Goodyear. Dimensions: wheelbase 93.5in, track: front 52in; rear 52in, length: 155in approx, width: 68in approx, height: 41in approx, weight less fuel approx 1500lbs, 40% front 60% rear
*McLaren’s record was only broken in 2003 by Fernando Alonso, when he won the Hungarian Grand Prix at 22 years 26 days, and in 2008 by Sebastian Vettel, 21 years 73 days when he won the Italian Grand Prix.