What went wrong at McLaren? Caught in the wrong concept

I n the World Cup table sees the balance for McLaren not that bad at all. The ninth of the Constructors' Championship 2017 was sixth this year. 30 points became 62. But the demands were different. McLaren wanted to close the gap to the top teams. They had said goodbye to Honda and stocked up with Renault engines. So there were no more excuses. Except for the one that the engine change was only finalized in September. And that put pressure on the development program.

Operations manager Simon Roberts doesn't even look for excuses: “We had to develop at the speed of light because we wanted to be ready on time for the start of the test. That's why we had various problems with reliability there. We just didn't have the time to properly integrate all the systems into the car. It had nothing to do with Renault. The problems were on our side. ”McLaren developed practically in two directions over the winter. There was a test version and then the actual MCL33 concept with the nostrils, which due to time constraints could only debut at the Spanish GP.

52 points before the summer break, 10 afterwards

The World Championship Table tells the story of McLaren this season. Before the summer break, there were 52 points, after that only 10. Fernando Alonso got 80 percent of the points for the team. Without the Spaniard, the result could have been really bitter. At the end of the season, not even the driving class of the former world champion helped. McLaren was fighting with Williams at the end of the field. McLaren engineers realized relatively quickly that something was wrong with the MCL33. “The winter tests didn't go according to plan,” admits Roberts. “We had problems with the stability, drove little. That cost development time and we struggled to understand the car. ”

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Fernando Alonso got 80 percent of the McLaren points.

The first big wake-up call followed at the GP Bahrain. Both cars got stuck in Q2. 'Some aspects of the car did not work as they should,' explains chief engineer Andrea Stella. “Then came our Spain package. The performances in Barcelona and Monte Carlo were decent. We knew we didn't understand some things, but thought we could still resolve them. In Montreal, reality caught up with us. We finally realized we had a problem. From then on, development practically stood still. ”

Larger front wheels produce larger air vortices

But where did the McLaren engineers take the wrong turn? Stella explains: “Our 2017 model was a good foundation. We wanted to develop that further. In 2017 we lost a lot to the Red Bull in certain corners. We wanted to remedy that, but transferred this weak point to the new car. In retrospect, we went too far in a few things and created a few aerodynamic problems with which we ran into a dead end. ”

The McLaren MCL33 was unable to maintain the downforce in corners over the entire course of the Hold in until you accelerate. To keep the downforce reasonably stable, McLaren made do with the mallet method. Bigger wings. They drove the air resistance up. And that cost top speed. The McLaren were among the slowest cars on the straight.

McLaren was not alone with the problem of fluctuating downforce. Stella blames the phenomenon on the wider cars. “The larger front wheels produce greater turbulence than in the period before 2017. The main task of aerodynamicists today is to get this turbulence under control. The wider sub-floor exacerbates the problem. Because it contributes more to the overall downforce than before. ”According to Stella, this is also the secret of the top teams:“ If you manage to control the downforce better over the entire curve, you will be in a different category. ”

Weak point was in slow turns

Like many other teams, McLaren discovered that the simulation tools were no longer sufficient. 'We have reached the limits of what a wind tunnel and CFD simulation can represent,' admits Stella. Therefore, from the Austrian GP onwards, McLaren switched to using the first practice session on Friday as a test session. Development parts came to the car, partly from the 3D printer, and the two MCL33 were stuffed full of sensors to compare the correlation between wind tunnel, CFD and race track. 'We turned every stone to find out where the error was,' reveals Roberts.

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Stoffel Vandoorne lost the training duel against Fernando Alonso with 0:21.

McLaren changed management over the summer and also changed the processes in the design office. At the same time, new measurement methods were developed in Woking to reduce the discrepancy between the laboratory and reality. “Our car wasn't that bad in fast corners. Unfortunately there are fewer and fewer fast corners. Even Pouhon in Spa is now full without any problems, ”says Stella. “Our weakness was mainly in slow corners. And the processes in these curves are incredibly difficult to simulate in the wind tunnel and CFD. ”

The deficits of the orange cars were particularly evident in the qualification. At the end of the season, McLaren rarely made it into Q2. The increase in form on Sunday is easy to explain. “The qualification shows the pure performance of a car. In the race there are many more variables that can cover up the weaknesses in the car. Good starts, good strategy and low tire wear can help. Our car was very nice to the tires. That often made us look better in the race. ”

Alonso benefited from a difficult car

After the engineers had determined that the MCL33 was caught in its concept, they tried the mistakes of the Understanding 2018 cars so as not to fall into the same trap in 2019. McLaren conducted a number of experiments to sort out the car's sore spots. Stella describes the difficulties involved: “These cars are incredibly complex. Even if you just want to test a new front brake vent, it will take you two months to design and produce. That is why we have produced many test components using the rapid prototyping process. But often it is not a detail that is to blame, but the interaction of many components. In order to get a better overall picture, we have changed our test procedures. ”

Simon Roberts is confident that the designers have understood all the problems. “It was a long process, not the one moment when we said: That's exactly it. We could have incorporated some of the findings into the current car, but that would have put pressure on the weight of the car. That is why the pace of development was in the second half of the seasonrather slowly. 'Stella adds:' It's not that we lacked the ideas. The concept itself simply had its limits. Many changes would not have been implemented. ”

The difficult-to-drive car played into the hands of Fernando Alonso. With the experience of 312 GP starts, the Spaniard has learned to avoid problems. Stella knows Alonso inside out. He was his race engineer for seven years: “Throughout his career, Fernando has always stood out from his teammates when the car was difficult to drive. Like in 2012 and 2014 at Ferrari. Vandoorne was much closer last year. Because the car was better. However, the current car produced unstable downforce in the rear. Stoffel suffered more from this than Fernando. “