Honda Power Unit Hardware & Software

[etusch]

Yes. Ai. The fact that biofuel draws a lot of heat during vaporization and the irregular ignitions in the Honda engine brought this to mind, and I asked Ai. It's a system used in direct injection engines and could easily be used in active prechamber systems. It seems that something can also be done with passive pre-chambers, with pre-chamber and piston designs. It's more about designing the exits of the flame jets rather than firing the pre-chamber twice.

[ispano6]

Moving this thread from the AMR team thread.

...

Turbo size can't be changed with aduo. Nobody is entirely sure what they did, but the most common rumours were changing vane shape and the number of them.

This is actually an important call out, regarding keeping the turbo size the same but changing the internals. Asaki mentioned this in his column, but I didn't get he was talking about Ferrari. He seemed to allude to Honda making a change in the turbo internals, even though it was not one of the stated changes that was openly revealed. There were some upgrades that were kept secret apparently, but whether there was a change to the turbo (like what Ferrari did) isn't openly revealed.

Asaki-san from his Sportiva column:

I suspect that Ferrari had a small A/R ratio (the ratio of the cross-sectional area of ​​the scroll flow path to the distance from the center of the turbine shaft to that cross-section), which determines the characteristics of the turbo engine.

　It appears that the turbocharger was designed with a focus on responsiveness, reducing turbo lag and improving torque and responsiveness at low RPMs. While it may not produce maximum power, it will improve acceleration from a standstill and cornering.

　In the early stages of the season, Ferrari took the lead thanks to its overwhelming starting performance, but in the end, Mercedes overtook them and they couldn't win several races. After that, things started to change a bit, and Ferrari's starting performance was inconsistent, sometimes good and sometimes not, and by the middle of the season, there was hardly any difference in the starting performance of each power unit.

My guess is that the Mercedes team may have slightly improved their starting performance. However, even if Ferrari got ahead at the start, Mercedes had consistently won races in the end, so there was no need to drastically change the characteristics of their power unit. I think they were just making minor adjustments.
...
　Conversely, the Ferrari team, having recognized that even with a strong start they couldn't ultimately win, shifted their development focus to improving race performance, even at the expense of their already strong responsiveness—in other words, increasing maximum power output. As a result, I suspect their starting performance has gradually improved.

　I think Ferrari's decision was ultimately correct. Their dominant performance at the start faded, but in return, they became stronger in races, with Lewis Hamilton winning the seventh race, the Barcelona-Catalunya Grand Prix, ending Mercedes' winning streak. Charles Leclerc also won the ninth race, the British Grand Prix.

I believe Honda's updates are basically heading in the same direction as Ferrari's. I think Honda's current situation is that they've sacrificed responsiveness and torque in pursuit of more horsepower, resulting in poor drivability and driver dissatisfaction.

　When regulations change significantly, manufacturers have various approaches to how to balance horsepower and response, and what kind of PU characteristics to create. And as they race more, they begin to understand what kind of PU characteristics are most efficient under the current regulations.

[etusch]

Moving this thread from the AMR team thread.

...

Turbo size can't be changed with aduo. Nobody is entirely sure what they did, but the most common rumours were changing vane shape and the number of them.

This is actually an important call out, regarding keeping the turbo size the same but changing the internals. Asaki mentioned this in his column, but I didn't get he was talking about Ferrari. He seemed to allude to Honda making a change in the turbo internals, even though it was not one of the stated changes that was openly revealed. There were some upgrades that were kept secret apparently, but whether there was a change to the turbo (like what Ferrari did) isn't openly revealed.

Asaki-san from his Sportiva column:

I suspect that Ferrari had a small A/R ratio (the ratio of the cross-sectional area of ​​the scroll flow path to the distance from the center of the turbine shaft to that cross-section), which determines the characteristics of the turbo engine.

　It appears that the turbocharger was designed with a focus on responsiveness, reducing turbo lag and improving torque and responsiveness at low RPMs. While it may not produce maximum power, it will improve acceleration from a standstill and cornering.

　In the early stages of the season, Ferrari took the lead thanks to its overwhelming starting performance, but in the end, Mercedes overtook them and they couldn't win several races. After that, things started to change a bit, and Ferrari's starting performance was inconsistent, sometimes good and sometimes not, and by the middle of the season, there was hardly any difference in the starting performance of each power unit.

My guess is that the Mercedes team may have slightly improved their starting performance. However, even if Ferrari got ahead at the start, Mercedes had consistently won races in the end, so there was no need to drastically change the characteristics of their power unit. I think they were just making minor adjustments.
...
　Conversely, the Ferrari team, having recognized that even with a strong start they couldn't ultimately win, shifted their development focus to improving race performance, even at the expense of their already strong responsiveness—in other words, increasing maximum power output. As a result, I suspect their starting performance has gradually improved.

　I think Ferrari's decision was ultimately correct. Their dominant performance at the start faded, but in return, they became stronger in races, with Lewis Hamilton winning the seventh race, the Barcelona-Catalunya Grand Prix, ending Mercedes' winning streak. Charles Leclerc also won the ninth race, the British Grand Prix.

I believe Honda's updates are basically heading in the same direction as Ferrari's. I think Honda's current situation is that they've sacrificed responsiveness and torque in pursuit of more horsepower, resulting in poor drivability and driver dissatisfaction.

　When regulations change significantly, manufacturers have various approaches to how to balance horsepower and response, and what kind of PU characteristics to create. And as they race more, they begin to understand what kind of PU characteristics are most efficient under the current regulations.

Here is a thought of my own: it is possible that Ferrari opted for a smaller turbo not just for throttle response, but perhaps to get everything working at lower RPMs—(more RPM more electric consumption) prioritizing maximum acceleration over top speed. Naturally, response time is crucial for this. So, what is the advantage of maximum acceleration? It allows the car to accelerate strongly out of corners and pull away from the competitor. Did this strategy fail to deliver, or did Ferrari simply not achieve the desired acceleration out of corners? I actually expected Ferrari to build a gap in the twisty sections—enough to stay ahead on the straights—even in races like the one in China, but they couldn't manage it; that surprised me. Furthermore, in some races they would initially outperform Mercedes but then fall back as the laps progressed by drop of tyre performance. Ultimately, the real issue might not be engine concept, but rather a car—specifically the rear end, suspension, aerodynamics, and perhaps the transmission too—that couldn't handle delivering more power earlier out of corners, combined with poor tire management.

[GrFD2]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

[diffuser]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

Because they changed the regs and that turbo is no longer legal. Split turbo is allowed but not the length anyone ran in in 2025. Plus the fuel pressure/fuel has changed. That would likely have affect turbo sizing.

[Badger]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

You need a bigger turbo at altitude.

[diffuser]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

You need a bigger turbo at altitude.

A smaller turbo can actually be advantageous in a race because:

• Less inertia → faster spool: A smaller compressor/turbine has less rotating mass, so it responds more quickly when the driver gets back on the throttle. That improves corner exits.

• Less exhaust energy needed to accelerate it: At altitude, the engine produces less exhaust mass flow because there’s less air going through it. A huge turbo can struggle to get enough exhaust flow to spin efficiently.

• Better transient response: F1 cars are constantly changing throttle and engine load. A smaller turbo tends to respond more quickly to those changes.

• The turbo doesn't need to move as much air: At altitude, the engine's natural airflow is reduced. If the turbo is appropriately sized for that reduced mass flow, it can operate closer to its efficient range.

A larger turbo has more ultimate airflow capability, so it can be better when maximum power is the priority. The problem is that at high altitude the engine has less exhaust gas available to drive that big turbo.

[Badger]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

You need a bigger turbo at altitude.

A smaller turbo can actually be advantageous in a race because:

• Less inertia → faster spool: A smaller compressor/turbine has less rotating mass, so it responds more quickly when the driver gets back on the throttle. That improves corner exits.

• Less exhaust energy needed to accelerate it: At altitude, the engine produces less exhaust mass flow because there’s less air going through it. A huge turbo can struggle to get enough exhaust flow to spin efficiently.

• Better transient response: F1 cars are constantly changing throttle and engine load. A smaller turbo tends to respond more quickly to those changes.

• The turbo doesn't need to move as much air: At altitude, the engine's natural airflow is reduced. If the turbo is appropriately sized for that reduced mass flow, it can operate closer to its efficient range.

A larger turbo has more ultimate airflow capability, so it can be better when maximum power is the priority. The problem is that at high altitude the engine has less exhaust gas available to drive that big turbo.

Holy AI slop

F1 has a max boost pressure and a max turbo shaft RPM, so smaller turbos may struggle to reach max boost at higher altitude due to the RPM limit and reliability. A larger turbo will not need to spin as fast to reach the same boost. The trade-off under normal circumstances would be more lag on the larger turbo, however, the era we are talking about (2014-2025) had the MGU-H which spun up the turbo independent of exhaust flow to eliminate all turbo lag. This made larger turbos significantly better at altitude. Honda likely ran bigger turbos during the years where they were more competitive at high altitude (2019 for example).

[etusch]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

First of all, Honda attempted the "size zero" turbo concept during their McLaren years. Later, they switched to a Mercedes-style design—a path that everyone except Renault eventually adopted and which had been the right choice from the very beginning which contains big turbos. We have no information regarding how the size of their turbo compared to Mercedes's.
It is not the case that Honda simply failed to carry that engine concept to this season. People greatly underestimate the impact of biofuel and the requirements. This is an internal combustion engine, and a fundamental element has completely changed. The combustion process had to be redesigned from scratch, and it likely requires much more preciseness. Actually, "likely" is the wrong word here; if that weren't the case, Honda wouldn't have found itself in this predicament. In other words, this isn't a scenario where the engine displacement remains the same and you just tweak the compression ratio—it’s not an engine you can simply fire up and run.
As seen with the latest update, the pre-chamber and piston designs were modified and more power was extracted, yet the desired level of control over ignition still hasn't been achieved. It is evident that working with this fuel is no easy task. They will either have to source information externally (which isn't really Honda's style) or go through a great many iterations...

[diffuser]

You need a bigger turbo at altitude.

A smaller turbo can actually be advantageous in a race because:

• Less inertia → faster spool: A smaller compressor/turbine has less rotating mass, so it responds more quickly when the driver gets back on the throttle. That improves corner exits.

• Less exhaust energy needed to accelerate it: At altitude, the engine produces less exhaust mass flow because there’s less air going through it. A huge turbo can struggle to get enough exhaust flow to spin efficiently.

• Better transient response: F1 cars are constantly changing throttle and engine load. A smaller turbo tends to respond more quickly to those changes.

• The turbo doesn't need to move as much air: At altitude, the engine's natural airflow is reduced. If the turbo is appropriately sized for that reduced mass flow, it can operate closer to its efficient range.

A larger turbo has more ultimate airflow capability, so it can be better when maximum power is the priority. The problem is that at high altitude the engine has less exhaust gas available to drive that big turbo.

Holy AI slop

F1 has a max boost pressure and a max turbo shaft RPM, so smaller turbos may struggle to reach max boost at higher altitude due to the RPM limit and reliability. A larger turbo will not need to spin as fast to reach the same boost. The trade-off under normal circumstances would be more lag on the larger turbo, however, the era we are talking about (2014-2025) had the MGU-H which spun up the turbo independent of exhaust flow to eliminate all turbo lag. This made larger turbos significantly better at altitude. Honda likely ran bigger turbos during the years where they were more competitive at high altitude (2019 for example).

It's the other way around. Smaller turbo will find it easier to reach max boost. They are lighter and spin more freely, therefore, deal better with loss of exhaust gas cause by thinner air at altitude.

[diffuser]

Honda’s compact turbo philosophy was a game-changer from 2021 to 2025. A smaller turbo gave Verstappen incredible boost response off the line for those lightning launches, and it dominated high-altitude tracks like Mexico, Austria, and Brazil, where thin air forces turbos to work overtime.
​My question is, why can't Honda could simply port that 2021–2025 architecture over to 2026 or 2027? They started from scratch to design a clean-sheet PU rather than adapting their old concept? (Sorry for my English)...Btw Honda have concerns about lubrication system because of the G force on the La Monumental. https://www.planetf1.com/news/honda-spa ... monumental

First of all, Honda attempted the "size zero" turbo concept during their McLaren years. Later, they switched to a Mercedes-style design—a path that everyone except Renault eventually adopted and which had been the right choice from the very beginning which contains big turbos. We have no information regarding how the size of their turbo compared to Mercedes's.
It is not the case that Honda simply failed to carry that engine concept to this season. People greatly underestimate the impact of biofuel and the requirements. This is an internal combustion engine, and a fundamental element has completely changed. The combustion process had to be redesigned from scratch, and it likely requires much more preciseness. Actually, "likely" is the wrong word here; if that weren't the case, Honda wouldn't have found itself in this predicament. In other words, this isn't a scenario where the engine displacement remains the same and you just tweak the compression ratio—it’s not an engine you can simply fire up and run.
As seen with the latest update, the pre-chamber and piston designs were modified and more power was extracted, yet the desired level of control over ignition still hasn't been achieved. It is evident that working with this fuel is no easy task. They will either have to source information externally (which isn't really Honda's style) or go through a great many iterations...

I don't want to re litigate this but for accuracy I'm 100% sure Renault did adopt the split turbo. Ferrari, may not have.

[etusch]

[etusch]

I don't want to re litigate this but for accuracy I'm 100% sure Renault did adopt the split turbo. Ferrari, may not have.

If I don’t remember it wrong renault and Ferrari put turbo and turbine next to each other and then Ferrari switched split turbo

[draghixa]

I don't want to re litigate this but for accuracy I'm 100% sure Renault did adopt the split turbo. Ferrari, may not have.

If I don’t remember it wrong renault and Ferrari put turbo and turbine next to each other and then Ferrari switched split turbo

I think Renault switched to split turbo in 2022, their last F1 engine.

[Badger]

A smaller turbo can actually be advantageous in a race because:

• Less inertia → faster spool: A smaller compressor/turbine has less rotating mass, so it responds more quickly when the driver gets back on the throttle. That improves corner exits.

• Less exhaust energy needed to accelerate it: At altitude, the engine produces less exhaust mass flow because there’s less air going through it. A huge turbo can struggle to get enough exhaust flow to spin efficiently.

• Better transient response: F1 cars are constantly changing throttle and engine load. A smaller turbo tends to respond more quickly to those changes.

• The turbo doesn't need to move as much air: At altitude, the engine's natural airflow is reduced. If the turbo is appropriately sized for that reduced mass flow, it can operate closer to its efficient range.

A larger turbo has more ultimate airflow capability, so it can be better when maximum power is the priority. The problem is that at high altitude the engine has less exhaust gas available to drive that big turbo.

Holy AI slop

F1 has a max boost pressure and a max turbo shaft RPM, so smaller turbos may struggle to reach max boost at higher altitude due to the RPM limit and reliability. A larger turbo will not need to spin as fast to reach the same boost. The trade-off under normal circumstances would be more lag on the larger turbo, however, the era we are talking about (2014-2025) had the MGU-H which spun up the turbo independent of exhaust flow to eliminate all turbo lag. This made larger turbos significantly better at altitude. Honda likely ran bigger turbos during the years where they were more competitive at high altitude (2019 for example).

It's the other way around. Smaller turbo will find it easier to reach max boost. They are lighter and spin more freely, therefore, deal better with loss of exhaust gas cause by thinner air at altitude.

A smaller turbo will need to spin extremely fast to reach the max allowed boost at higher altitude, this creates reliability issues (and there's a max turbo rpm too, 100k IIRC). Also, we've already established it's the MGU-H that span up the turbo on those cars, so the loss of exhaust gas doesn't matter because the turbo was always spooled. There's a reason RB was able to win in Mexico 2017 and 2018 with the infamous Renault engine (which had a larger turbo than the competition).

AI isn't covering up the gaps in your knowledge mate, it's exposing them.