|McLaren MP4/2 TAG-Porsche|
Under the guidance of new owner Ron Dennis, McLaren quickly re-established itself as a Grand Prix winning team in the early 1980s. A vital ingredient in this rise was the ground-breaking carbon-fibre monocoque chassis designed by John Barnard. What prevented the revived team from challenging for the world titles was the ageing Ford Cosworth DFV engine. The naturally aspirated V8 was still able to fight for victories but on raw power it was no longer a match for the latest generation turbocharged engines.
After getting the team back on track using the readily available DFV engine in 1981, Dennis carefully considered the options for a turbo-engine. The most obvious choices were existing or nearly ready engines like Renault's V6 and BMW's straight four. Both would require compromises to Barnard's designs, so it was decided that McLaren would commission the development of a bespoke engine from none other than Porsche. The German manufacturer had not been involved in F1 for two decades but its intimate knowledge of turbocharged engines made them the perfect partner for McLaren.
There was, however, one obstacle for Dennis to overcome; financing. Porsche were more than happy to develop the new engine but only if someone else paid for it. McLaren was in no position to carry the bulk of the costs, so an outside investor was required. Showcasing his business savvy, Dennis approached Mansour Ojjeh. His company TAG (Techniques d'Avant Garde) was at the time one of rivalling team Williams' biggest backers. The prospect of becoming a full partner and not 'just' a sponsor, inspired Ojjeh to switch sides. An investment of an estimated $5 million was made and accordingly the engines were officially badged 'TAG turbo'.
One of the key requirements for the engine was a block that was as narrow as possible to maximise the ground-effect tunnels under the car. Carefully weighing all the options, Porsche's chief engineer Hans Mezger settled for a V6 engine with an angle of 80°. Independently, Honda had come to the same conclusion for their upcoming F2 and F1 engine. By the time the first engine ran on Porsche's test-bench, in December of 1982, it had become clear that Porsche's efforts were partly in vain as ground-effect aerodynamics were banned from 1983 onwards. It was obviously too late to make any drastic changes to the design, so the original configuration was retained.
Displacing just under the 1500 cc limit, the engine had a short stroke, which allowed it to rev well over 10,000 rpm. Tucked in under each bank of three cylinders was a KKK turbocharger. Two sizeable intercoolers were used to minimise the intake temperatures. A Bosch sourced fuel injection system was fitted. Many of the engine's ancillaries were mounted into the front of the block and heads. The result was a very clean, compact and lightweight engine that according to the official figures produced around 700 bhp. It was also strong enough to be used as a fully stressed member of the McLaren chassis. The only sign of its origins was a small 'Made by Porsche' badge on the airbox.
In the summer of 1983 and little over a year after the development had started, the engine was ready to be raced. McLaren did not have a brand new car available and instead used the existing 'MP4/1' chassis that originally were fitted with the Cosworth DFV engine. The aim was not necessarily to go and win races right away but rather to further develop the engine ahead of an all-out assault in 1984. The prospect of a Porsche engined McLaren had lured double world champion Niki Lauda out of retirement and he was the first to get a taste of the new twin turbo V6. In the four races McLaren used the interim car, poor reliability was a big issue, as was persistent understeer.
With the lessons learned in the last bit of the 1983 season, Barnard returned to McLaren headquarters. Here he laid down the MP4/2, which in many ways was a direct development of the original MP4/1. One of the big changes was an enlarged fuel tank to cope with the turbo engine's thirst. Even the five-speed gearbox was identical to the one used in 1983 despite the hike in power of 200 bhp. Compared to most rivals, the MP4/2 looked bulky particularly due to the size of the side-pods. Behind them the body was tucked backed very neatly, wrapping the compact TAG-Porsche engine. The additional power also made it possible to fit 'barn-door' wings that created a staggering amount of downforce.
A year after bringing Lauda back from retirement, McLaren pulled another coup by signing the fast moving Alain Prost, shortly after he was fired by Renault. Two brand new MP4/2s were ready just in time for the season opener in Brazil. A pattern immediately emerged; the TAG-Porsche engine was certainly not the most powerful in qualifying when full boost was required but in race-trim it proved superior to thirstier competition. Alain Prost won straight out of the box and the two talented drivers would go on to dominate the season, amazingly using just three chassis between them to win 12 of the 16 races. Separated by just half a point Lauda was crowned champion ahead of his team-mate. Needless to say McLaren also won the constructor's trophy.
During the winter Barnard only made subtle changes to the all-conquering design. In accordance with revised regulations a smaller rear wing was fitted and the suspension was modified to accommodate for the switch from Michelin to Goodyear rubber. The existing cars were updated to MP4/2B and three additional cars were built. The sixth MP4/2 chassis was the first carbon-fibre tub built in-house by McLaren. The revised machine continued where the original had left as Prost won the opening round of the new season. The competition had gotten stronger and Lauda in particular struggled. Prost won five races and, in his final season, Lauda took one victory. It was enough for Prost to win his first driver's title and McLaren again bagged the constructor's crown.
Further refinements were made over the winter with the introduction of an all-new six speed gearbox as the biggest change. Revised regulations mandated a smaller fuel tank, so brand new tubs were needed for the MP4/2C. Lauda's vacant seat was taken by another ex-world champion; Keke Rosberg. Now in its third season, the MP4/2 certainly was no longer the fastest car in the field, not even in race trim. The Honda engined Williams had a clear edge. Prost nevertheless took four wins and was as consistent as ever. Surprisingly he managed to collect enough points to beat the Williams drivers Nelson Piquet and Nigel Mansell to the title; they seemed more interested in beating each other than Prost.
Before the season was over, Barnard left and his replacement Steve Nicholls designed a brand new car for 1987. This MP4/3 was once again powered by the TAG-Porsche engine. It did not prove to be a big enough step forward to catch the Williams Hondas. In the final season with the German engine, Prost won 'just' three races. After little over four seasons, the highly successful partnership, which had resulted in 25 race wins, three driver's titles and two constructor's titles, came to an end. The MP4/2 TAG-Porsche provided McLaren with the final push to return to the very top; a place it would not relinquish for many seasons to come. Prost's ultra-smooth driving style was perfectly suited to the car and 'Le Professeur' more than vindicated himself after being fired by Renault.
Article by Wouter Melissen, last updated on November 23, 2010
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