X-ray spec -- McLaren MP4/2

Two brave design choices brought dominating success, the car’s designer tells Keith Howard

In Formula One the 1980s were McLaren’s decade. From 1980 to ’89 the team won no fewer than five drivers’ and four constructors’ championships thanks to two remarkable cars from two different designers. Gordon Murray’s later MP4/4, which with minimal changes became the almost-as-successful MP4/5, was covered last month. Here it’s the turn of the car which vaulted the newly reconstituted McLaren International into the front rank of grand prix racing: John Barnard’s MP4/2 of ’84, which in MP4/2B and MP4/2C guises was still the car to beat in ’85 and ’86.

Two things set the MP4/2 apart: first was its carbon composite chassis, which Barnard had pioneered in the original MP4; second was the Porsche-designed and built TAG V6 turbo engine, which McLaren commissioned from the German manufacturer to a tight brief. Barnard envisaged an engine specifically designed to permit the most efficient underbody aerodynamics, and insisted that Porsche adhere unswervingly to the dimensional limits he specified. When the flat-bottom rule was hurriedly introduced for 1983, the Barnard masterplan was undermined, but not fatally: the car still won 12 out of 16 races in ’84 in the hands of eventual champion Niki Lauda (five wins) and frustrated runner-up Alain Prost (seven wins).

The story might have been very different but for the interventions of Williams’s Patrick Head and Marlboro’s John Hogan, as Barnard recalls: “I’d finished the Chaparral Indycar project and was just starting to get involved with Hector Rebaque’s team when it went pop. I told Patrick I was looking for a job and the next thing I knew Ron (Dennis) phoned up. His Project Four operation was running customer F2 and F3 cars but he wanted to get into F1, so we agreed that I would start designing an F1 car while he went looking for finance.

“We were almost at a point at Project Four where the F1 effort was going to have to stop because Ron had exhausted his potential sources of money when Marlboro said we could carry on if we got together with Team McLaren. McLaren had been in a steady decline and Marlboro, their main sponsor, was getting unhappy. Project Four was also sponsored by Marlboro for its F2 and F3 cars. Really it was John Hogan at Marlboro who pulled the two sides together.”

McLaren International, formed in late 1980, was the result. And the rest really is the stuff of F1 history.

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“Initially the turbo inlet was in the footstep of the coke bottle — that triangular grille you can see in the drawing. It was in quite a high-pressure region but the snag with it was that a lot of grit used to get blasted down into it from the rear tyre, despite the grille, and this damaged the impeller blades. So I got KKK, the turbo manufacturer, to make right and left-hand turbochargers for us. They thought I was nuts but I was then able to mount the turbos front to back, so I could take the inlet from just behind the intercooler. I have a feeling the drawing is wrong in that the car already has the turbo inlet in the sidepod side panel behind the intercooler, so I don’t think it would have had the grille in the floor. That would have been deleted.”

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“When it was obvious that we needed a turbo Ron and I looked at BMW’s four, but I wasn’t prepared to put tube frames on the back of the monocoque to support it. The other option was the Renault V6 but again it involved certain compromises. So we went through all the people we thought could make an engine for us. and went to Porsche. They said, ‘Here’s the price.’ We didn’t have vast budgets but we broke the costs down to a point where we could afford to buy the design, which I think cost us about DM 1 million.”

One of the few teething problems was a difficulty with engine starting: “We had a very small air starter which slid into a channel in the sump to engage with the flywheel. We had starting problems for a long time until we discovered that the body of the starter was turning inside the tube because we hadn’t got it fixed properly. It was as silly as that. As soon as we sussed this we had no more problems. Daft things like that can cause you all sorts of embarrassment.”

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“We had a pretty good wind tunnel set-up by then and I think we were well ahead of the other teams in terms of what we could do with our model — the way we could anchor and move it. So we had faith in our aero numbers. The combination of rear wing, winglets and diffuser worked tremendously on the MP4/2. That, to my mind, has always been the key: a car that has loads of grip at the back. The drivers build confidence in it immediately and, so long as you can dial out the understeer, you’re going to have a quick car. That’s what happened. We took the car to Ricard for the first run. Prost got in it and I can remember him saying later that after just two laps he was ready to go for a time. We knew from that first test that we had a strong car.”

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“Bosch’s engine-management system was a key part of the car, and a key part of that was Udo Zucker (who went on to found TAG Electronics), then a bright young engineer in their R&D department. This drawing shows two electronics boxes: I knew that if we went to one box the package could be two-thirds the size: Udo said it was more convenient for development this way but I insisted. We had some initial problems with the electronics, the classic case being the last race in ’83, where we ran the hack interim car I’d been forced to do mid-season (the MP4/1E).  We were quick and frightened everybody, including Renault. We were leading the race with only a handful of laps to go when a tiny relay failed on the electronics and put us out. I found out later that it came off a 2CV or something like that, and threw a wobbly about it. But Udo did a bloody good job.”

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Bottomed out by a rule change:

“By then ground effect was the big thing and everybody was working to get more from it,” says John Barnard. “One way I could see was to make the chassis much narrower at the bottom. That meant a big loss of torsional stiffness so I decided that we needed a new material.  I went to see British Aerospace, who were making cowlings from carbon composites, and decided to use that. I had to learn how to design with the material — it was completely different to metal. We made all the tooling and then found that the only people we could interest in wrapping and cooking the tub were Hercules in Salt Lake City. We shipped the tools to them and they sent back a raw monocoque that we had to fettle and bond together from five components — a main outer shell, a seat back, two internal panels and a bulkhead.” Frustratingly for McLaren, and Barnard in particular, much of the potential advantage of the MP4 /2’s bespoke engine was nullified before the car ever ran, as a result of the flat-bottom rule being agreed for 1983: “I reflect on that being one of my most annoying times in F1. I felt that by going to a flat bottom we’d given up 50 cent of the value of having that engine done. As far as I knew nobody else had gone to the trouble of getting the engine built to suit the package. Without the rule change we would have had aerodynamics to die for. We had a model in the tunnel that was producing some amazing efficiency numbers. I still feel that we got done by the flat-bottom rule.”