Honda Power Unit Hardware & Software

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
HPD
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Re: Honda Power Unit

Post by HPD » Mon Mar 05, 2018 12:35 pm

Honda RA61$H

Mclaren started developing the 2015 MP4-30 with the Size-zero concept in mind. Their partner, Honda, accepted that concept and designed the RA615H, but was forced to compromise powerto keep the PU compact. What was lost in power was supposed to be gained by aerodynamic performance, but that didn't work out; poor results persisted throughout the season.

Did they accept a lower output as inevitable given the dimension requirements? Or did they think that they could manage both, only to fail as a result?

Kakuda admits, "I don't think we fully understood how difficult it would be. "Although he is developing the PU at HRD Sakura, Kakuda nonetheless cannot be fully certain, as he joined the program in 09l'15—after the design ofthe RA615H was finalized. Thus, his explanations for the 2015 powerunit inevitably calls upon speculation based upon his expertise, in addition to his experience.

"We were starting from scratch. so we didn't fully understand the difficulty of developing a PU. This lack of understanding certainly played a part in our acceding to the chassis ' demands. when developing our first PU. However. once out on the track. we realized that there were a lot ofissues."

They had fitted the turbine, compressor, and the MGU-H inside ofthe V-bank, but this decision had backfired.

"The turbocharger's position inside of the V-bank limited its size. It's difficult to increase its efficiency without making it larger. ”

Unless the turbocharger's efficiency is increased, the MGU-H cannot be utilized fully, and the thermal energy cannot be harvested enough. This lead to an insufficient deployment ofthe MGU.

"Because the turbocharger was inside the V-bank. the induction system was oriented quite forcefully. When I first saw this I couldn't help but wonder. 'will this really work?' We were starting with a fresh mindset. but that resulted in us being unable to overcome reliability and performance hurdles.

New regulations in 2015 allowed for variable intake systems. Such systems are usually used to change the stroke of the intake funnel. increasing the charging efficiency. Combined with a turbocharged engine, simply increasing the charging efficiency does not necessarily increase output. so the system is sometimes manipulated to shut out air.
Either way. variable intake technology leads to an increase in output. so Honda adopted it without hesitation.

In the RA615H, packaging needs forced the plenum chamberto be flat. so the intake funnel for the cylinder banks could not be extended upward. Instead. they intersected one another horizontally. like crossed arms. Honda was attempting to change the funnel length in such a layout.

“Components were moving around rapidly in such a small space. I was shocked by its complexity when I first saw it."
That complexity may have backfired. as the PU struggled with sticky funnels in the first half ofthe season.


The focus for the 2016 RA616H was the improvement ofthe cramped induction system.

“We focused our improvements to the induction and turbocharger. On one hand. we wanted to recover the inefficiencies ofthe RA615H by freeing up the induction, while we also wanted to enlarge the turbochargers.

Afler negotiations with Mclaren. the allocated space for the engine increased somewhat. The additional space was used to raise the plenum chamber by 30mm. allowing for the branch from the plenum chamber to the cylinder head to
be a more optimal shape.

“Speaking of development for the 2016 season, we couldn‘t fully revamp the engine because ofthe Token system.
That partly led to our decision to center our development on the turbocharger and induction.


The 2017 RA617H saw widespread changes.

"I recall that the current regulations were confirmed in 2009. Constructors continuously competing in F1 since then were starting development quite early. but we only resumed our involvement in 2013. when our return to F1 was made public.“

The current regulations were implemented in 2014. Honda started competing in 2015. so on the surface it may seem like a 1 year delay—but Honda was lagging years behind in development. Additionally. the disparity in the quality of the development between a team that had prepared meticulously after years of continued competition. and a team that was just starting to regain its footing in F1, was quite large. Kakuda insists. though, that “it isn‘t excusable."

“Once we stop competing. everything is reset. and we lose the ability to recognize the issues that others find obvious.
Those issues were a revelation to us as we developed the PU, For example. the powertrain ofthe MGU-K is one example. We struggled a lotto develop it. but other constructors already had experience from developing KERS. and must have already solved a lot of issues"


One drastic change from 2016 to 2017 was the MGU—K. In the first two years, the output ofthe MGU-K was merged into the drivetrain at the rear ofthe PU via an independent geartrain. Although this wasn‘t entirely at fault, shaft failures from vibrations frequently occurred. This issue could have been one ofthose issues that teams with KERS experience had resolved long ago.

To reduce weight and friction, in addition to improve reliability. the RA617H merges the output ofthe MGU-K at the front ofthe PU instead. Issues from the newly designed MGU-K haunted the team in 2017.

"We had several issues in 2017. including drivetrain issues around the MGU-K. We may havejust been lucky in ‘15 and ‘16, but attaching a gearbox to the PU changes the resonance characteristics. which in turn changes the load on the PU. We attempted to anticipate this somewhat in our dyno tests. but issues still surfaced when we took to the circuit.

The newest-spec gearbox is often unavailable until immediater before the Shakedown. However. Kakuda admits that being unable to test the PU with an actual gearbox was a mistake. The mistake will be learnt from in their partnership with Toro Rosso.

“We are being very careful of our evaluation, because the structure ofthe gearbox is changing. Toro Rosso's gearbox isn‘t changing much from ‘17. so we started testing with that gearbox from an early stage in development.“

There were more struggles. The RA617H saw a drastic change in turbocharger placement. Until then. it was situated inside the V—bank. but the turbine was now placed in the rear. while the compressor was moved to the front. At the same time. the shaft connecting the compressor. MGU-H. and the turbine was lowered. allowing for the MGU-H—still inside the V—bank—to be lowered too. Moving the compressor and turbine outside ofthe V bank opened Lip more space. and enabled the design ofthe induction system to be more flexible.

"In the second half of '15. we were unable to increase power no matterwhat we did. With the basic design already in shape. there's not much room to reduce weight. or lower the center of gravity.
Reflecting now. our PUs Lip to the RA616H was unbefltting for an F1 engine. We therefore decided to do everything we can. and moved the turbo out ofthe bank to lower the center of gravity. We also increased our flexibility for the induction at the same time."


In the RA615H and the RA616H. the intake funnel faced each other horizontally in the flat plenum chamber. The spec 2 engine deployed for Round 10 in 2016 featured a more vertically positioned intake funnel. so the two sides converged at an angle. Combined with a straightened branch. air now flowed more smoothly.

The RA617H saw drastic redesigning ofthe intake flow. The variable intake funnels were arranged longitudinally. not laterally. situated in the front and rear. Air flowing in from the top now simply flowed into the rear ofthe power unit.

"[The branch up to the RA616H] had to circumnavigate the turbo. In the RA617H. we made it so that the air now flows from the front to back. to retain dynamic pressure. In the RA616H. the intake was sucking up turbulent air from the side. The pipes crossed when the variable intake system was active. which caused interference at times. The RA617H has a greater region ofvariablemanipulation too. We are looking to bring it to the optimal range for each revolution range.”

The protruding compressor now invaded the space for the oil tank. distorting its shape.

"Because ofthat. we faced issues at acceleration/deceleration and cornering where oil was not properly delivered. or burst out."

When a lot of oil was put in to ensure that it was delivered properly. it would flow into the intake duct under certain conditions. The compressor than took in that air. resulting in MGU-H failures.
The oil damaged the bearings. scrubbed offthe lubricant. thus increasing the temperature.

"We predicted these symptoms. so we attempted to test them on the bench."

They simulated the G forces from driving. and measured the lubrication ofthe oil.
"Partly because the sensor was new. we were unable to use it when we wanted to: we ran out of time. and testing started. lssues arose at testing. which damaged Mclaren's trust in us."

Like the MGU-K issues. the oil-related issues were also resolved and Honda are prepared for 2018.

The RA617H was updated to Spec 3.8 in '17. in which Spec 3—deployed at Baku—saw major changes to the specifications around combustion. In the RA617H, a prechamber was deployed. lCEs become more efficient as the air-to-fuel ratio becomes leaner. but it becomes harder to ignite.
The prechamber aims to resolve this issue. When the rich mixture around the spark plug in the prechamber is ignited. flames erupt in the main combustion chamber. burning the lean air.
Spec 3 had resolved the technical issues around that process.

"Ideally this was something we must have completed before the season started. But Mclaren wasn't willing to wait that long." says Kakuta with some regret. However. a breakthrough is in sight for 2018.
All credits to @FCIUS
https://www.reddit.com/r/formula1/comme ... h=d3ef5235

techman
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Re: Honda Power Unit

Post by techman » Mon Mar 05, 2018 1:13 pm

nice article

jagunx51
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Re: Honda Power Unit

Post by jagunx51 » Mon Mar 05, 2018 1:34 pm

Which one is easier, engine follow chassis OR chassis follow engine :?:
............!!!!

Talisman
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Re: Honda Power Unit

Post by Talisman » Mon Mar 05, 2018 2:04 pm

MrPotatoHead wrote:
Mon Mar 05, 2018 6:16 am
Of course your experience is more first hand than mine, but my experience did not show much difference - but it was meant more a compliment than anything else.
Its not a criticism but perhaps your experience and Wazari's experiences are not incompatible. There would be general qualities encountered while working with Japanese as a whole whilst Honda's culture within that could be very different to those of other companies.

I know American corporate culture is very different to European but within that too there is a lot of variation, I can't see Google's working culture sharing much with, say, GM for example.

techman
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Re: Honda Power Unit

Post by techman » Mon Mar 05, 2018 2:12 pm

Which one is easier, engine follow chassis OR chassis follow engine :?:
i think honda have learnt their lesson. it should always be build a chassis around the engine.

godlameroso
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Re: Honda Power Unit

Post by godlameroso » Mon Mar 05, 2018 2:53 pm

Best to build chassis around engine, then shrink wrap the chassis around the engine through development. So once a foundation is established you tighten up the chassis, and when the engine department makes gains in cooling packaging, the chassis department is ready with bodywork to take advantage of the engine gains.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

bosyber
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Re: Honda Power Unit

Post by bosyber » Mon Mar 05, 2018 2:54 pm

techman wrote:
Mon Mar 05, 2018 2:12 pm
Which one is easier, engine follow chassis OR chassis follow engine :?:
i think honda have learnt their lesson. it should always be build a chassis around the engine.
Given the lack of power, and success Ferrari had in 2014 after they made the same mistake of building a space-starved PU and couldn't compensate with the aero, that does seem the case; it also seems like it needed to be tried/learned the hard way, both by McLaren and Honda, instead of looking at where Ferrari went wrong (okay, maybe too late by then already to turn around, during 2014, but still seems very blue-eyed going in from Honda).

HPD, that interview is very impressive, and does give hope that Honda have turned a corner now, understand where they went wrong and know how to move forward.

ArcticWolfie
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Re: Honda Power Unit

Post by ArcticWolfie » Mon Mar 05, 2018 7:38 pm

HPD wrote:
Mon Mar 05, 2018 12:35 pm
Honda RA61$H

*cut*
All credits to @FCIUS
https://www.reddit.com/r/formula1/comme ... h=d3ef5235
"Ideally this was something we must have completed before the season started. But Mclaren wasn't willing to wait that long." says Kakuta with some regret. However. a breakthrough is in sight for 2018.
Does that mean the new combustion method isn't ready yet or will it be ready at the start of this season? Or is the "breakthrough" pointing at something else?

Thanks for the story :)

Wazari
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Re: Honda Power Unit

Post by Wazari » Mon Mar 05, 2018 9:15 pm

@Mr. Potato Head, I did not take your post as criticism. I just wanted to point out that IMO HRD is very "un-Japanese" when compared to most Japanese corporations.

I am surprised at how transparent and detailed the above article is. I did not expect Honda to allow Kakuta-san to be so open. I am not surprised how very politically polite the article was. I think it sums up from a 10,000 meter view of what happened and I agree with 99% of what is written.

Definitely easier to design a chassis around a PU then the other way around.

@PZ, I assume all your questions were answered in that article?

Breakthrough I believe refers to new combustion hardware/process. My understanding not ready yet...but will be mid-season. Come on 740 kW....please.............
If you can make the opposition flinch, you have already won.

Mudflap
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Re: Honda Power Unit

Post by Mudflap » Mon Mar 05, 2018 9:26 pm

PlatinumZealot wrote:
Mon Mar 05, 2018 5:35 am
Looks like the engine oil is different from the MGUH oil (obviously right?). And it seems the compressor sucked up the oil from the bad version 1 oil tank then somehow blowed engine oil into the MGUH bearings?! Can anyone explain how the compressor volute is connected to the MGUH bearings?

Pages 4 and 5.
https://abload.de/img/untitled4v4s2w.png
https://abload.de/img/untitled5t4s7t.png
Snorked wrote:
Mon Mar 05, 2018 2:19 am
Reddit user FCIUS is translating the article:

http://abload.de/img/untitled1wtjtw.png
https://abload.de/img/untitled2cjpnn.png
https://abload.de/img/untitled3zoso3.png
I'll do the rest once I eat dinner - please ignore any grammatical issues, as I didn't proofread the text.

Also sorry for the sloppy photoshopping.
https://www.reddit.com/r/formula1/comme ... h=d3ef5235
I don't think it is a separate lubrication system with different oil - the issue seemed to be that the bearings were improperly scavenged and flooded. Every single piece of automotive and aero turbomachinery I have ever seen had ring type seals which have a bit of a gap by design. Normally the higher pressure on the compressor and turbine side stops them from leaking - even more so when the bearing cavities are scavenged and their pressure is slightly lower than ambient.
My interpretation of the 'oil blowing' mentioned a while ago was that oil made its way into the scavenging air lines which normally pull from the top of the oil tank. This would result in a large vacuum in the bearing cavities preventing oil outflow.

I think Wazari stated that MGUH bearings failed due to oil starvation caused by pump cavitation, this article seems claim the contrary - too much oil the bearings. Since inadequate oil pump flow would alway fail crank mains or big end bearings first (generally the hydrodynamic bearings which require high flow rates compared to rolling element bearings) I tend to go with what the article says.
How much TQ does it make though?

Mudflap
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Re: Honda Power Unit

Post by Mudflap » Mon Mar 05, 2018 9:46 pm

johnny comelately wrote:
Mon Mar 05, 2018 3:37 am
i posted this in the general honda thread, so i suppose it should be in here:
They are allowed about 29 grams of fuel per second maximum (rate) and the power figure of 950hp, can someone calculate the energy content of the fuel ?
Works out at just over 51MJ/kg at 50% TE. Not too far off 44MJ/kg or so for pump fuel.
How much TQ does it make though?

Wazari
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Re: Honda Power Unit

Post by Wazari » Mon Mar 05, 2018 9:54 pm

Cavitation in the oil tank caused the problem. To stop oil starvation the tank was intentionally overfilled. This led to problems in several areas including bearings.
If you can make the opposition flinch, you have already won.

McMika98
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Re: Honda Power Unit

Post by McMika98 » Mon Mar 05, 2018 10:09 pm

Wazari wrote:
Mon Mar 05, 2018 9:15 pm
Breakthrough I believe refers to new combustion hardware/process. My understanding not ready yet...but will be mid-season. Come on 740 kW....please.............
740 kW !!! Thats a hugee leap in power. But how can you be so confident of the output if it has not been run on the dynos? Guess the testing in Hungary will be perfect time to launch this engine.

Also Honda have said they now have magic qual modes, is this with extra stuff or just running engine at full pelt?

Mudflap
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Re: Honda Power Unit

Post by Mudflap » Mon Mar 05, 2018 10:40 pm

Wazari wrote:
Mon Mar 05, 2018 9:54 pm
Cavitation in the oil tank caused the problem. To stop oil starvation the tank was intentionally overfilled. This led to problems in several areas including bearings.
Sure, if the oil level increases it is more likely for oil to get sucked into the scavenge lines. However your post on page 852 states that the issue was air into the the MGUH feed due to cavitation. So what killed the bearings - cavitation or overfilling?
How much TQ does it make though?

Wazari
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Re: Honda Power Unit

Post by Wazari » Mon Mar 05, 2018 10:52 pm

I'm being hopeful, not confident that 740 can be reached. It is being dyno'd. Qualifying mode is not magic. I understand that a full qualifying mode map has been tested and successful, mainly to do with ERS storage and deployment.

The MGU-H issue was a domino like effect. It wasn't as simple as a bearing lubrication issue. Oversimplying the shaft bearing connecting the compressor to the MGU-H had issues with lubrication and temps due to starvation, the "sealed" H bearings because of unexpected temps had an issue with oil-wash after starvation was patch remedied.
If you can make the opposition flinch, you have already won.