HOW IT BEGAN
McLaren might have won the British Grand Prix with its carbon-chassis MP4/1 in 1981, but it knew the writing was on the wall for for the ageing Cosworth DFV in the face of the mounting turbocharged challenge.
John Barnard had no option to start the search for a turbo engine, but he didn't like what he found.
Teddy Mayer, still a director of McLaren International for a few more months, reckoned he could arrange a supply of Renault V6s, but Barnard wasn't interested. He says his response was: "'I don't think it's very good'. It was based on a road car block, had a 90-degree V angle, and had all the pumps and bits and pieces scattered around the sides."
There was also a trip to Munich to see BMW's in-line four-cylinder turbo running on the bench. Again, Barnard wasn't interested.
"It was all mounted on subframes," he says. "I turned to Paul Rosche and asked if I could change the way it was mounted," recalls Barnard. "He said, 'no, you have to mount it exactly with those subframes'. As we left, I said to Ron , 'forget it, it's a compromise. I'm not going to run that'."
There was even a trip to Liechtenstein to see a mock-up of a straight-six turbo produced by star BMW Formula 2 engine builder Max Heidegger. That was a non-starter, too.
"He wanted to mount it in this carbon-reinforced box," remembers Barnard. "It was missing the point of an F1 engine."
Barnard knew what he wanted: "It had to be a stressed engine, mounted in the back of the tub in what I would call the Cosworth manner. I wanted all the pumps off the side and on the front of the engine. I didn't want anything down the side because we were still working on ground-effect underfloors at that point."
If there wasn't an engine out there that would meet Barnard's criteria, there was a simple solution: get someone to build one. And that's where Porsche came in.
"We went through a list of names - Cosworth, Weslake and people like that - before I think Ron suggested Porsche," he says. "A day or two later we were over in Germany talking to them."
Porsche, already a multiple winner of the Le Mans 24 Hours with turbo technology, was happy to oblige. But at a price. Then as now, the Stuttgart marque isn't just a manufacturer of road-going sportscars; it also operates as a gun-for-hire automotive consultancy.
A deal was done as early as October 1981 for Porsche to produce an engine to Barnard's strict dimensional requirements. There was a problem, however. McLaren had to find someone to pay for it.
"Within McLaren we had enough money to pay for the design of the engine only," recalls Barnard. "I forget how long that part of the process was, maybe six months, but Ron said within that time he was going to find the money."
That was where TAG came in. Dennis persuaded the technology organisation, already a sponsor of Williams, to enter into a joint venture with McLaren in a company to be known as TAG Turbo Engines.
The final piece in Barnard and McLaren's jigsaw was in place...
THE TAG PORSCHE HITS THE GRID
An engine bearing TAG badges - those of TAG Heuer to be precise - graced the Formula 1 grid for the first time in more than 30 years in Melbourne last weekend, and notched up a decent fourth-place finish in the back of Daniel Ricciardo's Red Bull. That contrasts with the DNF on debut of the original TAG turbo powerplant of the 1980s. But it wasn't meant to be that way.
The first TAG engine, paid for by the Ojjeh family's Techniques d'Avant Garde organisation, failed to make the finish in its first grand prix in the back of a McLaren in August 1983.
Niki Lauda retired his McLaren-TAG MP4/1E from the Dutch Grand Prix with brake issues, yet the new twin-turbo V6 designed and built by Porsche shouldn't by rights have been been racing that weekend. At least, not in the mind - and original conception - of the man who drove the project at the British team.
McLaren technical director Barnard didn't want to race the new engine until there was a purpose-designed car in which to install it. Racing the turbo that had begun testing in the back of an F1 chassis that summer would only be a distraction, he reckoned. There was no championship at stake for a team that had failed to get either of its Cosworth-powered cars on the grid in Monaco and there was that bespoke car to design, build and then test.
"You have to remember that we are talking about a relatively small team in those days: the drawing office was probably four or five people," says Barnard. "We were doing an all-new car for '84 and and trying to keep the Cosworth car as competitive as possible at the same time, and then someone comes along and says that you've got to put the new engine in a car to race now...
"I knew we were always going to run it and test it, but I didn't want to take the new engine to a race. And Ron would have gone along with what I wanted."
Lauda, who had returned to racing with McLaren the previous season, had other ideas. He saw the value in testing the new engine, correctly known as the TAG Turbo P01, in race conditions.
The Austrian failed to persuade Dennis of the virtues of racing that year, so he continued his lobbying at the door of sponsor Marlboro. And, according to the tobacco company's sponsorship man John Hogan, did it in a "very underhand way".
"At the British GP in '83, Niki couldn't help but tell the bloke who was in charge of Marlboro, Aleardo Buzzi, that McLaren was dragging its feet on introducing the turbo," recalls Hogan, one of the key players in the merger between McLaren and Dennis and Barnard's Project 4 organisation at the end of 1980. "Buzzi went apeshit, and I was made responsible."
The argument that ensued was predictably won by Marlboro. Six weeks later, Lauda was on the grid in Zandvoort with a turbocharged engine behind him. He wasn't driving a uprated version of the mule created out of a ground-effect 1982 car in which the TAG engine had tested at Porsche's Weissach research and development facility three weeks before. Rather, he was driving another iteration of the MP4/1 based on that year's flat-bottom C-spec Cosworth car.
A disgruntled Barnard had handed over the update of the MP4/1C to right-hand man Alan Jenkins. He recalls being told by Dennis to "forget about going home for the next month or so, you've got to get the car together in six weeks". The result of his labours was the MP4/1E, a machine to which he and Barnard refer, perhaps disparagingly, as the "interim car" to this day.
The first MP4/1E was raced by Lauda in the Netherlands before a second car arrived for team-mate John Watson two weeks later in Italy. The first McLaren-TAG was on the grid at four grands prix that year and wouldn't manage a finish in any of them.
"Those races taught us a lot of things that we wouldn't have had a clue about otherwise - we learnt an absolute tonne," says Jenkins, also Watson's race engineer. "If you look at the aero changes we made over those races in '83, they were massive. It took us a while to realise how much wing we would have to run."
Barnard admits, too, that much was learnt with the MP4/1E over the final four races of 1983. It is, perhaps, a begrudging admission.
"I suppose in some ways, looking back on it, it was good to do," he says. "We found out various things. But it put a lot of pressure on us at the factory to come up with this interim thing. Would we have learnt as much just going testing? You do always learn more going racing because you stress the car more."
The McLaren-Cosworth MP4/1C had been running carbon brakes, but they proved under-specced when the turbo-powered car arrived. It was the lack of braking that precipitated Lauda's smokey retirement at Zandvoort.
"The turbo car was running something like 15km/h faster on the straight, so there was a huge amount more energy to get rid of," says Barnard, who remembers temporarily ditching carbon for steel brakes on the MP4/1E until the South African Grand Prix. Drilled carbon discs were tried for the first time at the Kyalami finale, and it was at this point that McLaren made the decision to pursue the technology into 1984.
Lauda might have won in South African but for a late failure. He was only a couple of seconds behind race winner Riccardo Patrese's Brabham-BMW when an electrical problem put him out of the race.
The cause was the problem was the failure of a simple relay, and it turned out that the culprit was a road car component. Barnard remembers being told that it was from a Citroen 2CV, Jenkins (perhaps more plausibly given that German company Bosch produced the electrical and electronic systems) that its origin was a Volkswagen Kombi van. It matters not, but perhaps proves a point.
As does the fact that the car for which the TAG V6 had been designed tested but once before its debut in the Brazilian Grand Prix five months later. Barnard's fears that racing an interim car would detract from development of the MP4/2, a car that retained little from its predecessor except its family look, were borne out.
"Not surprising really". Those are the words with which Barnard responds to questions about the car being late.
"It was a big build," he recalls. "I pretty much carried over the front suspension after going to pushrods for '83 and the gearbox casing. The chassis was different, the aerodynamics were different, the rear suspension was different and the braking system was different."
The first MP4/2 tested at Paul Ricard less than two weeks before it had to be in Brazil for the season opener. So tight was the schedule, remembers Jenkins, that chassis #01 never returned to the UK before being flown to Rio de Janeiro. The second car, raced by new McLaren signing Alain Prost in Jacarepagua, was built up in the pits ahead of the grand prix.
It was MP4/2 #02 that gave the McLaren-TAG partnership its first of 27 grands prix victories in Prost's hands that weekend. Lauda led the race, too, and was out front and ahead of his team-mate when electrical problems struck mid-race.
With a bit more luck, it might have been a dream one-two for the new and bespoke TAG-engined McLaren. And that kind of debut, reckons Jenkins, was what Barnard always had in his mind when McLaren made the first approach to Porsche back in the summer of 1981.
"John being the perfectionist that he is," says Jenkins, "wanted to wheel McLaren's first turbo car out and finish one-two straight out of the box."