“Aero eats horsepower!” - Max Bartolini: Exclusive

Among the puzzles for Yamaha to solve as it seeks to bring the M1 back to the top of MotoGP is striking the optimum balance between straight-line speed, engine character and aero.

Despite winning the 2021 title, Fabio Quartararo struggled to overtake due to a lack of top speed.

The situation worsened in 2022 when a planned power upgrade was abandoned due to reliability concerns. 

“We were very busy developing a ’22 engine with a different level of performance in horsepower,” Lin Jarvis told Crash.net at the end of the 2022 season.

“Finally, however…  if you don't have reliability 100% guaranteed then you need to hesitate.

“We decided to stay with a conservative level of performance to be sure that we would retain the reliability.”

But Yamaha's wins dried up in 2022 and podiums in 2023.

In the aftermath of the '22 engine setback, Yamaha began a partnership with Marmotors.

Asked what the brief given to ex-Ferrari and Toyota F1 engine designer Luca Marmorini had been, Jarvis quipped: “Power, please!”

It didn’t happen overnight, but the M1 gradually climbed the top speed charts. However, the team's results often went in the opposite direction. 

At this year’s Sepang test, Quartararo set an impressive top speed, just 2.1km/h slower than the Ducati of Francesco Bagnaia and 3.1km/h from the KTM of Brad Binder.

But the Frenchman was only 11th fastest in terms of lap time.

At Mugello, MotoGP’s fastest circuit, it was a similar story: Quartararo set the third-highest speed in the grand prix yet finished in 18th place.

As ever in MotoGP, there’s no simple answer.

Test rider Cal Crutchlow warned top speed isn't everything and that Yamaha needed to regain its smooth engine character to exit the corners better. 

Quartararo was also increasingly concerned that the bike still lacked a lot of aerodynamic downforce compared to rival machines.

Improvements in both of those areas during 2024 saw Yamaha's top speed suffer but results improve, culminating in sixth for Quartararo at the Malaysian GP, despite being 19th on the weekend speed chart.

‘Aero eats horsepower!’

Monster Yamaha technical director Max Bartolini, who joined the project at the start of this year, explained the juggling act between aero, engine power and engine character.

“The Yamaha was quite fast [for top speed, at the start of the season] but in the meantime, we also developed the aero. And aero eats horsepower!” Bartolini told Crash.net.

“If you have power, you can use aero. And if you don't have more power, you cannot use more aero.

“So the engine at the beginning was quite powerful, but then we also developed the aero, to gain a little bit in handling and corner speed etc.

“But for sure we used power. Even if you make very, very efficient aerodynamics, it’s impossible to create downforce or side force without drag.

“So it's a bit slower on the straight [now] because the aero itself is improving and also because we moved the engine character a little in the way that Fabio likes, for the handling.”