The TAG Formula One engine

The TAG Formula One engine

TAG Story Porsche returned to F1 in the 1980s, building the engine that won McLaren two successive championships. Total 911 explores one of the most successful partnerships in the history of F1, made possible by Techniques d’Avant Garde. Written by Kieron Fennelly Photography by Porsche Archive.


Porsche’s foray into F1 was short but very sweet. We take a look at the story behind its fabled TAG engine.


When Formula One began in 1950, most of the participants built their own engines, but 20 years later, apart from Ferrari, almost all were using the Ford Cosworth DFV. Then in 1976, a group of enthusiasts in the newly formed Renault Sport persuaded président directeur général Bernard Hanon to allow them to build a Renault F1 turbocharged engine. The Renault men were impressed by the way Porsche had used turbocharging to win not only the Can-Am, but the World Sportscar Championship.

In the current three-litre Formula One, FIA rules permitted forced induction for engines up to 1.5 litres and Renault thought, rightly as it turned out, it had a chance. Development took several seasons, but by 1979 when the works Renault won the French Grand Prix, turbocharging was looking more feasible and other manufacturers, notably BMW, started building turbo engines; by 1982, Ferrari had also built one.

Since its world championship win with Hunt in 1976, the American-owned McLaren team had declined to the point where it was more or less obliged to merge with another team to have any chance of survival: it accepted an offer from Ron Dennis’s Project Four operation. The combined new team included designer John Barnard who had pioneered the carbon-fibre monocoque and with considerable investment from sponsor Marlboro, John Watson’s victory at Silverstone in 1981 was McLaren’s first Grand Prix success since 1977: the company would finish 6th in that year’s world championship.

But Renault’s turbo breakthrough was a portent of things to come and it was apparent to Dennis even before 1982 that turbocharging was the only way back to the top in F1. Clearly there would not be a 1.5 turbo Cosworth unit because Ford still believed its naturally aspirated three-litre was competitive. Dennis looked at the turbocharged possibilities. Neither Renault, now leading the championship, nor close rivals BMW seemed any more likely than Ferrari to share their turbo engines with another team. McLaren’s designer John Barnard’s advice was, “just go to the top.” So, in autumn 1982 Dennis sought a meeting with Porsche, the acknowledged turbo experts.

Dennis was received at Weissach by Helmuth Bott and Hans Mezger. Although Porsche had no involvement in F1, Mezger as chief motorsport engineer followed developments and attended the occasional Grand Prix. The Porsche men reacted positively to the McLaren boss’s approach, although they pointed out that Porsche had no interest in sharing the cost of developing an F1 engine, which was Dennis’s original plan. Weissach would however undertake to design and build one on a contractual basis. It was less than Dennis had hoped for, but keen to show commitment, he offered to Porsche to carry out a feasibility study. That would keep the project alive while in the meantime McLaren persevered with the long-serving Cosworth engine, and Dennis employed all his considerable imagination and contacts to obtain necessary financial backing. He approached Techniques d’Avant Garde, a Geneva-based brokerage which negotiated trade deals on behalf of Saudi Arabia with France and Great Britain.

Its young managing director Mansour Ojjeh, son of founder Akram Ojjeh, was seeking to promote a more positive image of the Kingdom in the west. Ojjeh junior’s introduction to motor racing had come in 1979 when he arranged for the national airline Saudia to sponsor the Williams F1 team.

An enthusiastic racing fan, Ojjeh accepted Ron Dennis’s proposal to become a partner in McLaren. Dennis argued that TAG stood to gain far more from active participation in a high-tech venture than merely painting its colours on a racing car. It was a persuasive if audacious claim by the Briton, but it paid off and both TAG and McLaren would in the longer term make a lot of money from the deal. An initial problem was Frank Williams, who demanded that his Williams team too should receive the Porsche engine, to which neither Porsche nor McLaren would have agreed, but finally Williams went to Honda which was developing its own F1 1.5 turbo engine. After advancing an initial $5m which allowed McLaren to draw up a contract with Porsche, TAG became the major shareholder in McLaren with 60%, while Ron Dennis who had bought out the company’s major American shareholder Teddy Mayer, held the other 40%. In 1982, Niki Lauda decided to return to F1 (after ‘retiring’ in 1978) amidst rumours that he needed the money to boost his airline, Lauda Air. Philip Morris, maker of Marlboro cigarettes and sponsor of McLaren, again saw the opportunity and offered Lauda $1million to drive for the team. Now Dennis was able to say to Porsche that not only was McLaren backed by Saudi money, it had Niki Lauda, champion in 1975 and 1977, as its leading driver.

This gave Bott the confidence to commit Porsche wholeheartedly to the project and by spring 1983 testing of the new engine, type 2623, was underway. As Porsche and McLaren had made only a vague public announcement about their cooperation, until a McLaren chassis was ready, Bott fitted a 956 with the new 1.5 turbo engine for initial trials at Weissach.

However, the sound of the high-revving V6 gave the game away and Dennis was angry when he learned that the first test of the turbo was not in a McLaren. This development, picked up in the motoring press, put both Porsche and McLaren under pressure they had hoped to avoid, as sponsor Marlboro was now pressing to see its expensive new driver racing what would become known as the TAG McLaren. Lauda too was eager to get the TAG engine into a chassis so the team could develop its grandeur nature during the remainder of the 1983 season.

There was tension between McLaren management and Lauda for most of the rest of 1983: Barnard and Dennis never accepted the need to race the TAG car – John Watson was driving the other McLaren entry, the Cosworth-engined car, competitively, but Lauda was determined to get practical experience rather than start 1984 with a car untried in competition. Lauda’s force of personality and the fact that he and Mezger worked particularly well together meant that his view prevailed. At the end of the 1983 season, McLaren obtained the services of another top-class driver: Renault and Alain Prost had fallen out and Dennis subsequently persuaded the Frenchman to join McLaren, replacing the faithful Watson. The Prost-Lauda combination would prove inspired: between them, Lauda and Prost would win 12 of 16 Grands Prix in 1984, and Lauda won the championship from Prost by only a half point – Prost had scored only 4.5 points instead of nine for his win at Monaco as the race was abandoned because of rain before full distance.

The TAG design was clearly the best engine that season: the fastest of the competition was usually Patrese’s Brabham BMW, but it lacked the TAG’s reliability. Nevertheless, the Weissach engine was far from perfect and there were both electrical and mechanical failures, although Hans Mezger said that was inevitable in such a highly stressed unit that was so new. A measure of its progress was that the TAG began the 1984 season with about 715PS, but by mid-1985 gave 860PS. During that year, Prost was unstoppable, winning his first championship with six victories, helped by a more advanced Bosch Motronic system which told the driver how much turbo boost he could use without running out of fuel. The 1985-built TAG engines were also mechanically more reliable and lasted through the equally successful 1986 season (Prost won again despite strong competition from Michele Alboreto’s Ferrari).

Weissach built only a few more type 2623s for 1987, making a total of 53 TAG V6 engines. Gerhard Küchle’s mechanics systematically rebuilt the engines and after some discussion with Horst Marchart, who was in charge of the financial side of the TAG contract, McLaren agreed to pay for such rebuilds at cost. The Porsche-McLaren partnership did not always run smoothly: Ron Dennis complained at one point that every time he opened Christophorus, there seemed to be an article crowing about Porsche’s F1 success without mentioning McLaren; however, he did later acknowledge that there were many instances where Helmuth Bott did not charge McLaren for work which, contractually, he could have. Mezger said that if he sent a component to another department to be stress-tested for example, he did not send McLaren an extra bill for this work. In his autobiography, he says he did not think Porsche made much money from TAG McLaren.

For the 1986 season, it was apparent that competitors were catching up, especially Williams Honda. Although Prost was champion again, he won only four Grands Prix. Lauda had left the sport (for good this time) and Prost’s teammate was Keke Rosberg, the 1982 champion. The Finn was fast: his TAG McLaren started from pole position once and led three races, but he never managed better than 2nd place (at Monaco) and a handful of 4ths. He complained volubly about his TAG McLaren, failing to interpret the Motronic fuel monitoring correctly and running out of carburant at Hockenheim, and he was never able to master the car’s understeering tendencies. Prost by contrast used the McLaren’s characteristics to his advantage, recognising that although the Williams Hondas were faster, the TAG had better fuel consumption: he used his boost control judiciously and his tactics worked when the Japanese-engined cars had to stop for fuel. It was this ‘thinking’ approach which earned Prost his second championship and his nickname among English speakers as “the professor”.

1987 marked the final year of the TAG contract and it would prove the least successful. Prost and his latest new teammate, Stefan Johansson, who had come from Ferrari, finished 1st and 3rd in the opening race in Brazil, but subsequently Prost took only two more Grands Prix. McLaren finished 2nd in the manufacturers’ championship, a long way behind the Williams Hondas. The TAG engine was hit by mechanical problems such as the recurrence of alternator drive belts failing. Mezger admits that the way these cogged belts turned over on their pulleys mystified him and these repeated failures made for difficult relations with McLaren. But the TAG was now producing up to 1,060PS and revving to 12,300rpm, almost twice the power achieved in 1983 when it was conceived. Continued reinforcement to cope with the stress of ever more power was beginning to generate imbalances and vibrations which ultimately caused failure. The type 2623 had run its course. Bott informed Dennis that Porsche would not redesign the TAG for 1988, which in any case would be the last year of the 1.5-litre turbos before F1 returned to natural aspiration. Dennis expressed dismay though the decision cannot have completely surprised him, and he had already explored the idea of using the Honda engine which would arrive at McLaren together with the shining talent of Ayrton Senna. Porsche was already suffering the effects of the declining US dollar and its reduced motorsport expenditure would be directed towards its Indy car campaign in North America (which it would abandon less than 18 months later).

As ever with its competition creations, Porsche tried to find other uses for its type 2623 V6: a helicopter engine for German builder MBB was one possibility, abandoned when tests showed no improvement in economy over MBB’s existing turbines; Weissach’s R&D department also looked into use in a road car, but this was also inconclusive, as was one final experiment, installing the 1.5 turbo unit in a 930. Several weeks were devoted to this around March 1987, but the resultant 930 did not run smoothly and the project clearly needed much more development; the prototype was shelved, uncompleted. After some rancour, in the end, both parties parted company amicably. Dennis praised Bott, Marchart and Mezger, “the three heroes who put TAG on the map,” and his present of a McLaren chassis complete with TAG motor to Porsche was seen as an extraordinarily magnanimous gesture: normally Dennis was obsessive about not allowing his technology to fall into third party hands. For Porsche, Hans Mezger put it succinctly: “Ron Dennis was a 100% reliable partner: what he said, he did.” The TAG cooperation was a memorable achievement: 25 victories in 68 Grands Prix over four short years. In the history of Formula One, it remains a unique accomplishment by one team.


BELOW August 19, 1984 at the Österreichring: McLaren-TAG-Porsche car 8 driven by Niki Lauda and car 7 driven by Alain Prost.

The TAG Formula One engine

RIGHT Alain Prost in action during the 1986 F1 season

“Porsche tried to find other uses for its type 2623 V6: a helicopter engine for German builder MBB was one possibility”

BELOW Hans Mezger, to the right, taking notes during testing at Weissach in 1983.

ABOVE Testing with the TAG engine in Weissach, 1983. From left to right: Hans Mezger, Julius Weber, Peter Falk, and Ron Dennis

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