An unusually detailed report on the development of their power unit for 2021 arrived from Honda, which resulted in Max Verstappen's victory in Imola. This year’s version of Honda’s powertrain, the RA621H, proved to be arguably the strongest at the moment, further confirmed by Pierre Gasly’s form in the AlphaTauri.
Originally, this upgrade package was planned for the new rules that were postponed to 2022. However, after the decision to withdraw Honda from Formula 1, it was decided to introduce the planned upgrades immediately. Still, they want this stint in F1 to end up at a high level.
“Originally, the plan was to introduce a new powertrain structure with the new rules from 2021. But then, for various reasons, it was decided not to start upgrading,” said Yasuaki Asaki, head of powertrain development.
“Thinking about this has completely changed after the decision was made to withdraw from the sport. I went to President Hachig and told him that we would really like to implement a new drive unit structure in our final year in the sport.
He kindly accepted the request. "
Asaki adds that the changes to the power unit were very thorough and required a large amount of work. “It wasn't an easy task at all, given how much the architecture of the power unit has changed.
First of all, we changed the position of the camshaft, lowered it a little lower to be closer to the ground and made the space around it more compact. ” “The goal of all these changes was to make combustion more efficient.
For this purpose, we changed the valve angle, and as a result, the camshaft position was changed. We also changed the position of the cylinder head and made it more compact, which resulted in better aerodynamic efficiency and a lower center of gravity.
” “Another change is the distance between the cylinders that we have reduced, which is why we got a smaller and shorter engine." "On the old engine, the left side of the engine block was more forward than the right, and with the new engine, we replaced it, so the right side of the engine block was moved forward and the left side back.
” Asaki said they had to improve all key parameters to stay competitive with their main rival. “We have improved combustion efficiency. Changes around the camshaft have improved the engine. Due to the laws of physics, the amount of energy stored changed, and this meant that the amount of energy generated due to exhaust gases decreased."
"What we have done compared to last year is to increase the crankshaft output to ensure a satisfactory level of exhaust gases as well as their temperature. ”