The McLaren MP4/2 was used by the Woking team between 1984 and 1986. The single-seater designed by John Barnard picks up the legacy of the MP4/1, the first Formula 1 car to boast a carbon fiber chassis. Driven by the TAG Porsche engine, the car allows the English team to win three drivers' titles in the years 1984, 1985 and 1986 with the MP4/2, MP4/2B and MP4/2C versions, and two manufacturers in the years 1984 and 1985 with the versions MP4/2, MP4/2B, triumphing 22 times in the 48 Grand Prix disputed. Let's go and discover one of McLaren's most significant single-seaters.
The Porsche TAG engine
John Barnard obsessively follows a precise aerodynamic and chassis philosophy, which requires an engine capable of adapting perfectly to the lines of the British designer.
To do this, Ron Dennis makes the Porsche engine available to him: the agreement between the Woking team and the German car manufacturer was signed in December 1982 and financed by TAG, a Luxembourg holding owned by the Saudi franc Mansour Ojjeh, at the era partner to fifteen percent of Ron Dennis in the context of McLaren.
Without the push of the TAG, Porsche would have hesitated to return to Formula 1, both for the costs and for the poor results obtained in the 1960s. But the collaboration between McLaren and the Stuttgart car manufacturer immediately gave the hoped-for results: the German engine fits perfectly into the car designed by Barnard, ideal in terms of size and also the wheelbase of the single-seater that would have housed it. An advantage from the point of view of handling, especially in slow and tortuous sections, where a certain agility is always required.
Porsche, which in order to return to Formula 1 claims and obtains the TAG name because it does not want to link its brand to a project that was initially considered to be unsuccessful, opts for a type of supercharging by means of two turbochargers, one per bank. These specific components are made by another German company, KKK, which provides Porsche with a product that is as efficient as it is reliable. But since John Barnard outlines a specific design, the British designer requires certain characteristics in order to be able to build a single-seater with efficient aerodynamics.
The meeting point between Barnard and the engineers
The compromise between the demands of the McLaren designer and the technical requirements of Mezger's group comes through the adoption of a V between the cylinder blocks of the engine of 80 degrees, ten degrees less than the canonical 90s that were initially designed to the drive from Porsche.
The center of gravity is thus slightly raised, but in this sense the overall dimensions of the car body are reduced, which is more streamlined in the side-rear area. A targeted study to which is added the advanced positioning of the exhaust manifolds and turbochargers, thus making the tail section more streamlined, giving Barnard the opportunity to create a larger diffuser, which guarantees excellent efficiency from the aerodynamic point of view.
This aspect guarantees a significant advantage, since it gives the possibility to discharge the power to the ground and make the most of the drive torque as a function of the grip which is guaranteed by the downforce generated by the extractor.
The total mass of the unit, equipped with the two turbochargers, is 150 kilograms, a very low weight given that the German car manufacturer uses aluminium and magnesium alloys. The first examples of the Porsche TAG V6 come with a mechanical injection system, supplied by Bosch, while later the electronic one is used, the same used in the Group C World Championship on the 956 world championship prototype.
For this reason, before installing the engine on the Formula 1 chassis, the six-cylinder is mounted on a Porsche 935 suitably modified to accommodate it, to carry out tests.
Aerodynamic revolutions and the birth of the Coca-Cola area
In addition to the aforementioned characteristics, the exchangers are advanced in the sides, whose design is rather tapered in front of the rear wheels to better facilitate the passage of flows. It is a new design for this era, which is then taken up by everyone, marking a turning point. These bellies, particularly narrow in the rear area, take the name of Coca-Cola sides, since the shape recalls the neck of the glass bottle of the famous drink.
In addition to these new details, new rear suspension triangles are added, which are lowered to optimize the entire design in relation to aerodynamic efficiency. The 1984 regulations allow teams to use tanks with a higher capacity than in 1983, as refuelling was used in the previous season, so McLaren installs a component on the MP4/2 that can hold 220 liters of fuel.
The first tests, carried out in 1983 by Niki Lauda, show a power of 550 horses at 10,500 rpm, a not so exaggerated difference compared to the old Cosworth DFV, while the torque is decidedly higher, even if the engine suffers from turbo-lag, i.e. a response delay between the moment the pilot accelerated and the moment the engine increased its rpm.
But all the initial problems are solved before even starting the 1984 season. The 1984 season was dominated by McLaren, with Lauda managing to triumph over teammate Prost by only half a point, also obtaining the constructors' title.
A domination that, in any case, is not given by the most powerful engine of the lot, even though it unleashes 715 horses in the race and 800 in qualifying at 11.200 rpm, raising the turbo pressure; as previously mentioned, the strength of the McLaren MP4/2 lies in the integration between engine and chassis, which makes tuning easier, and the experience in terms of consumption and electronic engine control, gained by Porsche and by Bosch in endurance races with the 956 engine. Useful ingredients to make this car successful and unbeatable for three years.
Simone Pietro Zazza