New competition cars

McLaren MP4/4

At one time, a brand new car winning its first Grand Prix was an outstanding achievement, but nowadays it seems to be an accepted thing, especially where McLaren International is concerned.

At the end of last season the McLarenTAG-Porsche contract ended and the Woking-based team, masterminded by Ron Dennis, switched its allegiance to the Japanese Honda firm for the supply of engines. This meant a major redesign of its cars, and the best thing to do was to start from scratch with a clean drawing-board.

The very successful Porsche-powered McLarens had been designed by John Barnard, and when he left to join the Scuderia Ferrari much of his design philosophy and thinking naturally remained behind with those who had been working with him. Gordon Murray moved from the Brabham team to McLaren as Technical Director, and found waiting for him a highly-skilled and dedicated workforce led by Steve Nichols and Neil Oatley, who were more than capable of carrying on where Barnard had left off.

With the change to Honda power in the offing there was little point in doing much during 1987 other than to continue the development of the existing car. But once the 1987 season was over, work could start in earnest on an entirely new car. Apart from the new Honda V6 turbocharged engine, this had to incorporate changes to comply with new FIA rules, principally in moving the driver-compartment rearwards, so that the driver's feet did not extend further forward than the centre-line through the front wheels. With fuel tank capacity being reduced from 195 litres to 150 litres by the new rules, and the power-output of the Honda engine being strangled by an FIA limit of 2.5-bar boost pressure in place of the previous 4-bar limit, radiators and inter-coolers could be reduced in size.

The whole project looked after by Steve Nichols was a designer's dream, for there was no need to make compromises in order to use anything from the 1987 cars. Everything could be designed from scratch, and the whole car could be envisaged as a complete and integrated package.

While Nichols ran the design team working on the new car, Murray and Dennis liaised with the Honda Motor Company in Tokyo. Familiarisation tests with the Honda engine were carried out using a "hack" machine built up from one of the 1987 cars, allowing engineers and drivers to acclimatise to Japanese engineering while the new project progressed on paper.

For the new limited-power 1988 formula, Honda re-designed the four-camshaft V6 twin-turbo 11/2-litre engine, allowing it to be mounted considerably lower in the new chassis than had previous installations in Williams and Lotus cars. McLaren International designed a new gearbox/final-drive unit to take advantage of this and, with the reduction in the size of fuel tank, radiators and inter-coolers, the whole car could be substantially reduced in bulk -- not that the 1987 car was bulky.

Design philosophy was aimed at a compact and agile car, retaining the neat and svelte integrated look which all McLarens have had since John Barnard took over the engineering. While the first of the new cars was hurriedly flown to Imola for some last-minute initial running before going to Rio, the second and third cars were completed to a very tight schedule, and much work was done during the two days of practice for the Brazilian GP.

Happenings in Brazil are reported elsewhere, but suffice to record that the McLaren MP4/4-Honda V6 cars took pole position and third place on the grid. One of them led from start to finish, the other ran in second place for a time but was subsequently disqualified for a rule infringement. First time out with a dominating victory says it all. McLaren International can justifiably feel pleased with itself.

The McLaren MP4/4 is designed round a carbon-fibre composite monocoque tub, made in the Woking factory with materials supplied by the American Hercules Aerospace firm. The Honda RA 168-E engine attaches to the rear of the monocoque with the dry-sump oil-tank integral with the McLaren six-speed gearbox/final-drive unit. The V6 engine is turbocharged by two IHI units, one to each bank of three cylinders, and not surprisingly Honda engineers look inscrutable when asked about the power output!

Suspension coil-spring/damper units are mounted inboard for all four wheels, the front ones operated by pull-rods and the rear by push-rods. Carbon-fibre brakes are fitted on all four wheel-hubs, and the overall weight of the car is as near to the 540kg minimum as the engineers can make it, erring on the safe side by a kilogramme or two.

From the performance of the new car in Brazil one can estimate that, at 2.5-bar boost pressure and mixture adjustments to go through the race on 150 litres of fuel, the Honda engine is probably giving 650-700 bhp. DSJ