Matra MS80: Jackie Stewart's first title-winning F1 car

“Understeer was also a problem with the MS10. We corrected that by altering the weight distribution to make the front of the car lighter. We moved the oil tank back to between the driver and the engine, and to keep the MS80’s increased fuel load back we widened the side tanks to create the car’s coke bottle shape. We reduced unsprung mass by replacing the 15-inch wheels with 13-inch rims at the front, and by fitting inboard rear brakes. Changes to the suspension geometry to improve camber change at the front and toe-in at the rear made the car more stable and better to drive, but didn’t gain us much in lap times.

“The key to the MS80’s success was that it was a good all-round performer, without necessarily being the best in any particular area, and that’s what you need to win races.

To win you need everything to be right: a good chassis, good engine, good tyres, good driver and good organisation. In 1969 we had all that, whereas Lotus was still recovering from the death of Jim Clark.

“One of Stewart’s qualities was that he gave good feedback to the engineers. It’s often overlooked how vital this is, not only to adapt the car to each circuit but to guide the engineering team in future development. That was one of our strengths in ’69: the MS80 was the MS10 corrected, and we’d had the right information about everything that needed fixing.”

Matra’s aerospace factor

“Matra’s aerospace experience contributed in various ways. We used aviation techniques to build the car’s body, particularly in the structural fuel tanks which included several partitions that a bag tank would have precluded. These increased the body’s torsional stiffness. Matra aerospace subcontractors, who were used to precision construction using light metals, built the car. They could make components to high levels of accuracy, which was particularly important with the fuel tanks to prevent leakage from the glued and riveted joints. Before wings were banned, the aerospace division also advised us on the best aerofoil profiles to use.”

Matra’s decline and fall

“Stewart switched to March in 1970 because he wouldn’t race our car with a Matra engine. At that stage in its development the V12 was a weak point, but we never thought to return to the Cosworth: once we began to use the V12 there was no going back. Matra boss Jean-Luc Lagardère was determined that we should use it, and the French government had loaned Matra money to develop it. In fact we went downhill slightly in each of the five key areas I’ve described. A major problem with the chassis was that the rules changed so we couldn’t use the structural fuel tanks. We had to use bag tanks, and that affected the chassis’ torsional stiffness.

“From 1970 the Le Mans programme became more important, and Matra didn’t have the finances to put a full effort into F1 as well. We were disappointed to quit F1 after ’71. To us it was a failure. But 1969 was the best year of my career: my memories of it are exceptional.”