Time Machine: 1991 BRM P401 & P531
BRM - one of motor racing’s most famous marques - is to return to international competition, with an all-new World Sportscar Championship contender, and is also to become the manufacturer of an exciting road car.
The new BRM models - P351 and P401 - are to be developed in parallel. They will be powered by purpose-developed V12 engines, and will be built to the highest standards of design, technology and quality.
The new BRM project has evolved from a two-year development programme undertaken by the British company, Mangoletsi Design Group. During the course of the programme, several confidential racing and road car projects were undertaken, and these led to a proposal that Rubery Owen (Holdings) Limited should re-establish BRM, as a manufacturer of racing Sportscars and competition-style road cars.
Rubery Owen, the owner of BRM, has received many proposals over a period of years, all of which have been rejected. Very careful evaluation of this concept, however, proved it to be both technically and commercially viable, and it is now to be taken to fruition.
Rubery Owen is entering into partnership with Airflow Management Limited, a member of the Mangoletsi Design Group, in BRM Limited.
The technical centre, administration and marketing operation of BRM is to be based at Congleton, Cheshire, under the management of John Mangoletsi and the Design Director, Paul Brown. The first prototype of the BRM P351 racing car will be produced at Congleton. Subsequent P351 chassis will be assembled in the headquarters of the BRM racing team, which will be located at the Donington Park race circuit in Leicestershire, under the supervision of the Team Manager, Ian Dawson.
The circuit is adjacent to Tom Wheatcroft’s world-famous Donington Collection, which is the home of no fewer than nine historic BRM single-seater racing cars.
The race programme with the new BRM P351 will commence in 1992, although one car may be raced at the end of the 1991 World Sportscar Championship season. The first prototype BRM P401 road car is scheduled to run in 1992, and production will begin in 1993.
A number of prestige companies are cooperating in the BRM venture, among them Shell, Dunlop, Courtaulds, Motor Panels and AP Racing.
The BRM project is launched on 3 January, 1991, at the Auto Sports International show at the National Exhibition Centre, in Birmingham.
THE NEW BRM CARS
Both the newly announced BRM models, the P351 racing car and the P401 road car, are completely new from the ground up. The BRM concept is that the racing car will contribute much of the technology in the road car.
The BRM P351 will be designed and built purely for competition in the World Sportscar Championship, which is currently undergoing a major relaunch by FISA, motorsport’s governing body. It will feature leading-edge technology throughout, with a chassis and body made from the latest composite materials, advanced electronic systems, and a normally aspirated, V12 engine.
In all technical respects, the BRM P401 will be equivalent to (or superior than) many so-called ‘supercars’, yet the new car will emphatically not be of this genre. While it will have the flavour of a competition car for the road, it will be built as a regular production car, and will sell for around £200,000. The styling of the prototype is clean and distinctive, with a hint of tradition, although clearly derived from that of a competition model.
The BRM P351 will be based on an extremely rigid monocoque chassis made by Courtaulds from advanced carbon composite materials, with honeycomb cores in Nomex and aluminium. Its four-cam, 3.5-litre, atmospheric V12 engine will be bolted directly to the rear of the monocoque ‘tub’ and the six-speed transmission will be rigidly attached to the engine, in a longitudinal location. The power train will be a fully stressed chassis member and will carry all the loads of the rear suspension, braking and aerodynamic operations.
The bodywork will also be made from carbon composites and its final design will result from intensive development in the BRM wind tunnel. The car is expected to weigh no more than 750 kgs (the minimum weight limit for World Sportscars) and the engine is projected to develop well in excess of 600 bhp, revving to 12,500 rpm.
The BRM racing team expects to be at the forefront of electronics technology and will derive enormous benefit from the Precision Technology system, which will provide significant advantages in the all-important area of development testing. Emphasis in the design of the new car has been placed on achieving very high levels of adjustability of its handling and aerodynamic functions.
The design team of BRM has been engaged for more than two years on active research into a World Sportscar programme and has recently undertaken further redesign of its project, involving a substantially revised aerodynamics package and many other refinements. Thus the BRM P351 has derived from the longest technical development of any of the new-generation Sportscars which are being produced for the new, 3.5-litre engine formula.
Close attention has been paid to the ‘packaging’ of the BRM P401. The trend in ‘supercars’ has been towards excessive length, width and, in many cases, weight. The new BRM road car will be 163 inches long and 72 inches wide, yet the car will have a spacious cockpit, with headroom for a 6ft 2ins driver. The use of a carbon composites for the monocoque chassis and the bodywork, and the relatively low weight of the V12 engine, will keep its weight down to 22-23 cwt (about 1150 kgs).
The BRM 4.0-litre V12 engine of the P401 will be derived directly from the 3.5-litre unit of the P351 racing car. In the P401, this engine will run at about 5000 rpm less than its racing capability in the P351.
The target power output for the P401 unit is between 375-400 bhp at 7500 rpm, and the engine will develop 350-400 Ibs/ft of torque. In order to achieve high torque and good response, the P401 engine will be fitted with twin superchargers, linked to the engine management system, which will automatically disengage them when they are not required.
The torque-to-weight ratio will be enormous but, so as to enhance safety (particularly on a wet road), the six-speed BRM transaxle transmission will feature a ZF torque control differential.
The BRM P401 will be distinctively and enduringly styled, compact but spacious. Its supercharged V12 engine will deliver its power smoothly, through a six-speed gearbox, and its massive torque will be safely handled by a torque control differential. This car, in short, is projected as the ultimate road car in terms of its driveability and response.
Chassis & Body
Courtaulds carbonfibre composite construction with honeycomb cores in Nomex and aluminium. Engine bolted direct to rear of chassis. Twin ground-effect air tunnels, pillar-mounted rear aerofoil.
Single racing seat. Cranfield microprocessor-driven graphic display. Full Cranfield & Precision Technology engine & chassis data-logging & telemetry system.
BRM four-cam V12 at 60deg, 48 valves, 3.5 litres, normally aspirated, water-cooled. Frontal air intakes, side-mounted water radiators. Full engine management system. Dry sump. Lead-free Shell fuel (102 RON). Rigidly mounted north-south mid-engine location, as fully stressed chassis member.
BRM six-speed transaxle gearbox with Hewland three-shaft, 3.2-inch centre gears, mountings for rear suspension wishbones.
Unequal length wishbones front and rear, with outboard-mounted Bilstein variable rate spring/damper units.
Wheels & Tyres
OZ magnesium wheels, 16-inch diameter all-round, fitted with Dunlop radial racing tyres.
Brakes & Steering
Carbon discs, AP Racing six-pot calipers. Rack-and-pinion steering.
Wheelbase 2700mm (106.3ins)
Length overall 4500mm (172.2ins)
Width overall 1936mm (76.2ins)
Height overall 1025mm (40.4ins)
Weight 750 kgs approx
Chassis & Body
Courtaulds carbonfibre composite construction. A-frame location for engine & transaxle package. Twin ground-effect air tunnels. Rear body-mounted wing.
Two seats (leather), uncluttered cockpit, clear instrumentation, air-conditioning.
BRM four-cam V12 at 60deg, 48 valves, 4.0 litres, twin superchargers, water-cooled. Frontal air intakes, front-mounted water radiators. Full engine management system. Wet sump. Lead-free, three-way catalyst converters. Flexibly mounted north-south midengine location.
BRM six-speed transaxle gearbox with ZF synchromesh gears and torque control differential with mountings for rear suspension wishbones.
Unequal length wishbones front and rear, with outboard-mounted Bilstein variable rate spring/damper units.
Wheels & Tyres
OZ magnesium wheels, 16-inch diameter all-round, fitted with Dunlop radial tyres (225/50 ZR16 front, 255/50 ZR16 rear).
Brakes & Steering
Steel discs, AP racing four-pot calipers, servo-assisted. ZF Servotronic variable weighting speed-related power steering.
Wheelbase 2490mm (98,Oins)
Length overall 4145mm (163.1ins)
Width overall 1828mm (72.0ins)
Height overall 1190mm (46.9ins)
Weight 1150 kgs approx
Very high levels of technology are now required for the design and manufacture of top-level racing cars and high-performance road cars. These are beyond the scope of the traditionally small, entrepreneurial companies which have been so effective in the past, and which have formed the backbone of this type of business.
Consequently, a fundamental aspect of the new BRM strategy has been the inception of an advanced technology centre, which is located at the new BRM headquarters in Congleton, Cheshire. BRM’s technical centre, now nearing completion, embodies leading-edge technology in such areas as aerodynamics, data logging, telemetry and track-testing equipment. The long-established pattern and buck-making shop has been expanded.
It is an essential principle of BRM that the P351 racing car will develop much of the technology for the P401 road car. This principle applies to all aspects of the new BRM projects, including chassis, bodywork and engine development.
Chassis & Bodywork Development
A 1:3 scale, moving floor wind tunnel is currently being installed at Congleton, which is innovative in that the moving floor has a turntable, enabling yaw measurements to be taken.
The data logging and telemetry systems which will be used for testing the BRM cars are extremely advanced. BRM will employ the Precision Technology system, which can position the car within 1 centimetre on the race track (in ‘real time’ telemetry), demonstrate the line through the corners, and take measurements of all the dynamic functions every 10 milliseconds, producing a printout in real time.
Precision Technology is the most advanced development tool of its type available in the industry today. In addition, it offers the unique track-testing facility to measure the slip angles of the tyres, which directly quantifies the understeer and/or oversteer characteristics of the car. This, in turn, relates back to the aerodynamic data gathered in the wind tunnel, in respect of yaw, and so on. This is the first time that the loop between experimental development and hard data on the race track has been closed.
In order to be competitive at the highest levels of motorsport, it has become essential to deploy a permanent test car, with advanced data collection which is continuously referred back to the technical centre for evaluation and improvement. The Donington Park circuit is now being wired for the Precision Technology system, and will thus form a permanent test base for both the BRM projects, on the site of the BRM racing team headquarters.
The Precision Technology systems will be available for hire by other racing teams.
At the heart of both the P351 and P401 projects lies the new BRM engine. The true heritage of BRM in Grand Prix racing is that it raced its own chassis and engines. It was preferable, therefore, that BRM should return using its own power unit.
In order to evolve the optimum engine for World Sportscar racing, and with the Le Mans 24 Hours race particularly in mind, it was decided to use a V12 configuration. The all-new BRM engine is a 60 degree V12, with 48 valves. A 3.5-litre, normally aspirated version of this power unit is in the course of development for the P351 racing car. The P401 road car will be equipped with a 4.0-litre version of the same engine, with twin superchargers.
The development of the V12 in both its forms requires the application of technology at the highest level. The base engine will be ready for dynonometer testing within a few months, but the development programme of the power train will be lengthy and intensive.
BRM’s Technical Partners
No one technical centre is capable of embracing all leading areas of technology and, therefore, the policy of BRM has been to engage the assistance of the best international companies in each industrial field.
Shell, which is currently at the forefront of racing technology in Formula 1, will provide the BRM race programme with special, high-octane fuels and high-performance lubricants.
Dunlop, a company with no fewer than 29 Le Mans victories to its name, will not only cover the tyre contract for the BRM racing car, but will also develop special tyre sizes and compounds as required, using the data derived from the Precision Technology system.
Both Shell and Dunlop are renewing highly successful associations with BRM. No fewer than 15 of BRM’s 17 Grand Prix victories were achieved with Shell fuels and/or oils, and 13 were won with Dunlop tyres.
Courtaulds, which has a wealth of experience in Formula 1 and Sportscar racing chassis technology, will supply the advanced materials for the monocoque chassis and other composite components of the BRM P351 racing car. Courtaulds will actually produce the ‘tubs’ to BRM’s specifications, and will carry out special development work on the carbon composite monocoque for the BRM P401 road car, so as to enable cost-effective production quantities to be manufactured.
Motor Panels, which built both the Rover BRM gas turbine cars for Le Mans, will provide body engineering design and development facilities in order to ensure the build quality of the P401 road car. Jointly with IBM, Motor Panels operates an internationally known CAD/CAM technology centre, located in Coventry, which is at the leading edge of both technology and legislation in automotive body structures and fittings.
AP Racing, the world market leader in carbon brakes and clutches for top-level competition use, is supplying its latest, six-pot brake calipers, and carbon brake discs and clutches.
Discussions are in progress with two of the leading engine technology specialists for detailed analysis of the structure of the new BRM V12 engine, cooling and lubricant flow, gas flow, port and combustion chamber performance, and reliability at high revolutions of the valvegear and other moving parts. For strength, lightness, and control of vibration and harmonics, finite element analysis technology will be used extensively.
The new BRM projects will employ the technological expertise of these and other international companies which will become involved as the programme progresses during 1991.
Based on original BRM press release