Honda Power Unit Hardware & Software

[GhostF1]

Honda throws cold water on the-race's absurd claims of lacklustre battery tech.

https://global.honda/en/F1/features/202 ... ry/kakuda/

When it comes to the battery, is it fair to think that the performance advantage from the previous PU can be carried over?
“That’s what we believe—and what we hope. Even after the decision to end our activities, battery development continued, not limited to F1 alone. Because of that, it has evolved further, and it’s an area we’re confident in.”

What performance advantage? No one can look at the traces from last season and tell me Honda had better deployment than Merc.

It was a well known fact, across the paddock, the Honda had a distinct advantage in it's deployment and regen abilities. It had been mentioned several times by Merc personnel as well. While their battery had a significant lifespan advantage over the season.

[GhostF1]

It has been mentioned several times now.

2026 has banned split-turbos. So Merc and Honda have had to adjust. This plus the static compression ratio reduction, which nerfs their ability to use their rapid combustion technique, almost looks tailor-made to scramble any tricks/development breakthroughs anyone had found, to properly bring everyone down to square one again.
18:1 was only just enough, in combination with fuel composition work, to keep that combustion technique stable. Almost infuriating the FIA have introduced a regulation that directly reduces the efficiency of the ICE. Goes against their whole M.O for F1. In my opinion.

[Badger]

Honda throws cold water on the-race's absurd claims of lacklustre battery tech.

https://global.honda/en/F1/features/202 ... ry/kakuda/

What performance advantage? No one can look at the traces from last season and tell me Honda had better deployment than Merc.

It was a well known fact, across the paddock, the Honda had a distinct advantage in it's deployment and regen abilities. It had been mentioned several times by Merc personnel as well. While their battery had a significant lifespan advantage over the season.

I prefer to go by what I can actually see in the telemetry, and there Merc clearly had more deployment on energy limited tracks. Whether that was down to the battery, or the MGU-H, or something else, I don’t know.

[GhostF1]

What performance advantage? No one can look at the traces from last season and tell me Honda had better deployment than Merc.

It was a well known fact, across the paddock, the Honda had a distinct advantage in it's deployment and regen abilities. It had been mentioned several times by Merc personnel as well. While their battery had a significant lifespan advantage over the season.

I prefer to go by what I can actually see in the telemetry, and there Merc clearly had more deployment on energy limited tracks. Whether that was down to the battery, or the MGU-H, or something else, I don’t know.

I appreciate that and that's all well and good. It just goes against what a majority are seeing.

[Badger]

It was a well known fact, across the paddock, the Honda had a distinct advantage in it's deployment and regen abilities. It had been mentioned several times by Merc personnel as well. While their battery had a significant lifespan advantage over the season.

I prefer to go by what I can actually see in the telemetry, and there Merc clearly had more deployment on energy limited tracks. Whether that was down to the battery, or the MGU-H, or something else, I don’t know.

I appreciate that and that's all well and good. It just goes against what a majority are seeing.

Classic case of belief perseverance. Look at recent evidence instead of what was true in 2022.

[Bill]

It has been mentioned several times now.

2026 has banned split-turbos. So Merc and Honda have had to adjust. This plus the static compression ratio reduction, which nerfs their ability to use their rapid combustion technique, almost looks tailor-made to scramble any tricks/development breakthroughs anyone had found, to properly bring everyone down to square one again.
18:1 was only just enough, in combination with fuel composition work, to keep that combustion technique stable. Almost infuriating the FIA have introduced a regulation that directly reduces the efficiency of the ICE. Goes against their whole M.O for F1. In my opinion.

Most team are having problems with the news fuels apparently because the got components in them that combust at different temperatures so i doubt that having a pu with high compression ratio is a good idea .it could easily lead to engine knocking.

[Stu]

It seems they’ll be releasing one segment per day until the full image is revealed on the 20th.

https://ibb.co/wNyDpP2N

Has anyone nailed what those two cylindrical fittings are on the top? For reference, this is the Honda RA621H:

https://upload.wikimedia.org/wikipedia/ ... RA621H.jpg

Not yet along with what @AR3-GP mentioned, we have also had throttle bodies (1 per plenum, plenums within V), now that the variable length inlets have been banned and FBW throttle is a torque request there could be efficiency gains to be had in reducing the number of controlled orifices. It would surprise me to see an air-air intercooler mounted above it (where the plenum is located on the last generation of PU’s).

[GhostF1]

It has been mentioned several times now.

2026 has banned split-turbos. So Merc and Honda have had to adjust. This plus the static compression ratio reduction, which nerfs their ability to use their rapid combustion technique, almost looks tailor-made to scramble any tricks/development breakthroughs anyone had found, to properly bring everyone down to square one again.
18:1 was only just enough, in combination with fuel composition work, to keep that combustion technique stable. Almost infuriating the FIA have introduced a regulation that directly reduces the efficiency of the ICE. Goes against their whole M.O for F1. In my opinion.

Most team are having problems with the news fuels apparently because the got components in them that combust at different temperatures so i doubt that having a pu with high compression ratio is a good idea .it could easily lead to engine knocking.

Completely. And that seems to be the general consensus. Although wouldn't we rather let the teams, manufacturers, engineers determine what's possible? Without the suits slapping an arbitrary limit that restricts them even trying.

[Badger]

Most team are having problems with the news fuels apparently because the got components in them that combust at different temperatures so i doubt that having a pu with high compression ratio is a good idea .it could easily lead to engine knocking.

That conflicts with the comments we've heard from the people who ought to know.

Ben Hodgkinson

From a purely technical point of view the compression ratio limit is too low. We have the technology to make the combustion fast enough, so the compression ratio is way too low. We could make 18:1 work with the speed of combustion that we've managed to get, which means there's performance in every tenth of a ratio that you can get. Every manufacturer should really be aiming at 15.999 as far as they dare when it's measured.

[vorticism]

There is a third charge pipe cover (gold colored) low at the front (could be one of two), which would presumably be arriving through the vee from the compressor.

What people are calling the intake plenum I still say is the charge pipe. It looks too small and simple, has a thick wall, and a flanged interface. It is sized at about twice the area of one of the plenum connections. If Honda are using a '22-era Merc-type intercooler it would make sense to have all the charge pipes converge at the front above the engine in that location.

The two "horns" on the upper side are also striking. "The horn-like bulges are necessary because a standardised boost pressure sensor is required so that the FIA can monitor the maximum boost pressure," explains Kakuda. "For demonstration purposes, we mounted it where it is clearly visible."

Do you have a link to this interview?

[AR3-GP]

Do you have a link to this interview?

It will have to be translated:
https://www.motorsport-total.com/formel ... n-26012007

[bigblue]

From The Guardian, presumably recycled from reports elsewhere,

That this was no small matter was emphasised by Honda as they launched their new engine. “Regulations do not have everything listed very clearly, bit by bit,” said their chief executive Toshihiro Mibe. “There is a lot of room for interpretation as well and this is a part of the race. So for the FIA, it’s up to them to decide on whether it’s good or bad. For Honda, we have a lot of different ideas, and we would like to discuss with the FIA to understand if our ideas are accepted or are not OK.”

Tetsushi Kakuda, Honda’s F1 project leader, went further in admitting their powerunit development was “not necessarily” going as expected. Koji Watanabe, president of Honda Racing Corporation, warned that the regulations were challenging and that “perhaps we will struggle”.

[PlatinumZealot]

It has been mentioned several times now.

2026 has banned split-turbos. So Merc and Honda have had to adjust. This plus the static compression ratio reduction, which nerfs their ability to use their rapid combustion technique, almost looks tailor-made to scramble any tricks/development breakthroughs anyone had found, to properly bring everyone down to square one again.
18:1 was only just enough, in combination with fuel composition work, to keep that combustion technique stable. Almost infuriating the FIA have introduced a regulation that directly reduces the efficiency of the ICE. Goes against their whole M.O for F1. In my opinion.

It doesn't nerf the rapid combustion technique you know. What they mean is that the piston shape is so integral to the jet ignition that they have to start the combustion design over from a blank slate even though the cylinder and engine architecture sounds similar on paper.

[GhostF1]

It has been mentioned several times now.

2026 has banned split-turbos. So Merc and Honda have had to adjust. This plus the static compression ratio reduction, which nerfs their ability to use their rapid combustion technique, almost looks tailor-made to scramble any tricks/development breakthroughs anyone had found, to properly bring everyone down to square one again.
18:1 was only just enough, in combination with fuel composition work, to keep that combustion technique stable. Almost infuriating the FIA have introduced a regulation that directly reduces the efficiency of the ICE. Goes against their whole M.O for F1. In my opinion.

It doesn't nerf the rapid combustion technique you know. What they mean is that the piston shape is so integral to the jet ignition that they have to start the combustion design over from a blank slate even though the cylinder and engine architecture sounds similar on paper.

If this is the case, although a lot of work for them, it is good news. This quote is what I was referring to.

“From our perspective, the high-speed combustion approach that delivered results with the previous PU is now largely unusable due to compression ratio limits and changes in fuel flow. That means we have to find new ideas to improve performance. Other manufacturers are in the same situation, so it really becomes a competition of ideas.” - Tetsushi Kakuda

Also, their previous mentioning of the 18:1 regulation limit being restrictive to an optimum variant of the technique just raised some alarm bells. My concern comes from its stability in racing conditions and reg restrictions at a significantly reduced CR. There was a time that even every gear change caused them combustion stability issues when running that method on the 618/619/620 which we know were all running below 18:1. The RA621 which was at regulation maximum, they specifically mention it allowed them to create a more complete variant of the system.

Of course I'm not doubting them for this year. But there will be massive hurdles to get it stable, continuously at such a reduction. Likely a lot of fuel work going on right now.

[PlatinumZealot]

Lower compression ratio is more stable for engines. Less prone to knock.

I think he is alluding to the shape of the piston surface when he says that.

The manufacturers relied on a pre-chamber ignition however it is suspected thar the crown of the piston helps to shroud the pre-chamber when fuel is injected. It's easier with a higher piston crown. That is my theory.