Honda Power Unit Hardware & Software

[Per]

Generator mode could cause compressor stall if your compressor is dependent on high rpm to deliver boost. This is because generator mode puts a drag and slows down both compressor and turbine.

No, just no. Generator mode puts a drag and keeps compressor/turbine speed constant, harvesting any excess power (Pt-Pc). If your harvesting mode is slowing the compressor down to a point where it stalls, you're just being plain stupid with the way you control your MGU-H.

Regarding the second part of your post, exactly how do you come to the conclusion that you need battery power while the MGU-H is trying to harvest? That's kind of defying the whole concept of harvesting.

[Wazari]

I can safely say that with this turbine, compressor, MGU-H set up with its complex electronic control systems, compressor stall is not an issue.

[trinidefender]

Generator mode could cause compressor stall if your compressor is dependent on high rpm to deliver boost. This is because generator mode puts a drag and slows down both compressor and turbine.

Slow down a speed sensitive turbine which uses high rpms to create boost and you can stall it. More so if you no longer have ERS power to compensate for the inertia of the mgu-h. So while going full throttle down the straight you have no battery power to compensate for the drag the mgu-h places on the turbo while it's trying to harvest, add in a rpm sensitive compressor that needs high rpm and you slow it down with the mgu-h and you get a partially stalling compressor.

What are talking about won't happen in a centrifugal compressor. Your understanding is a bit off.

Let's first look at the MHU-H. The MGU-H is not either full output or full generator mode. The ERS computer will be able to control how much load is on the MGU-H when it is generating mode to control compressor rpm. Therefore by this logic regardless of what happens the compressor rpm will not slow enough to "stall" (which it cannot do btw).

Now let's look at the compressor itself. Let's assume the other condition can happen where the MGU-H can drag the compressor speed down (which it can't). As the compressor slows down it will not stall. All that will happen is that The pressure downstream of the turbocharger will reduce and that the ICE will generate less power.

Compressor stall is a result of to high pressure downstream of the turbocharger. This can result from shutting a throttle valve closed (if the throttle is downstream of the compressor), compressor wheel damage, a poorly designed compressor that is to "large" (using simple terms) for the ICE and creates to high a PR (pressure ratio) for the flow going through the ICE or a few other factors.

Last point I would assume that all the manufacturers leave enough power in the ES to run the MGU-H if needed. This leads me to a further question, are the ancillaries and ECU etc drawing power from the ES or do they have a separate battery?

So to finally close this argument I hope now you will understand why the compressor will not stall in the manner you describe.

*edit* you may get very momentary stall (fractions of a second) if the compressor speed reduces drastically very quickly, however definetly not like what you are describing at all.

[djos]

When we were working on it at the early stages we didnt realise straight away that you could bypass the ES completely between the H and K and there was much debate about whether a direct link powering all the time would be legal or not as it seemd to be cut off by the Mj limit specifications.

"Citation needed".

My Memory, Of my Job - 2011

Sounds interesting, doing what with who?
(Genuine question, pm me if you don't want the info public)

[Facts Only]

I was at McLaren as assistant "Unfathomable Sentence Writer" for Ron Dennis.

[djos]

I was at McLaren as assistant "Unfathomable Sentence Writer" for Ron Dennis.

Smart ass!

[gruntguru]

What's to argue? Unless you actually think you understand turbos better than the Honda engineers.

What specific time on the video do you think sounds like compressor stalling?

Main straight, back straight, take your pick, any time the car gets to 8th gear.

"Specific"
adjective
1.
having a special application, bearing, or reference; specifying, explicit, or definite:
to state one's specific purpose.

2.
specified, precise, or particular:
a specific sum of money.

[gruntguru]

Sorry Facts Only. Strongly disagree with the idea that Honda failed to anticipate the level of exhaust recovery available and what to do with it (drive the MGUK directly). Your guys might have missed something in 2011, but blind Fredddy would know in 2013 that the V6 formula is a "turbocompounding" formula with energy storage and KE recovery.

Beyond that, Honda had a year to watch the racing, gather data from McLaren (and others), run sims, run PUs on the dyno. All of Honda's problems will be attributable to packaging the engine in a car and finding those problems that don't happen on the dyno or the computer simulation.

[wuzak]

Grunt, it appears that Honda did have that very issue. As did Ferrari in 2014.

As for what happens when the battery is full/lap allowance expenditure gone, you can still fill it up (just cannot use more than 4MJ) and if that is not an option that is what the wastegate is for.

[GoranF1]

There are a few articles out there like this one saying Honda has hit trouble whit new PU on dyno recently.
Maybe @Wazari could look into it.

http://www.f1i.com/infos/le-v6-turbo-ho ... fiabilite/

[Joseki]

There are a few articles out there like this one saying Honda has hit trouble whit new PU on dyno recently.
Maybe @Wazari could look into it.

http://www.f1i.com/infos/le-v6-turbo-ho ... fiabilite/

"les quatre par pilote n’y suffiront pas…"


How can they know anything about Honda when don't even know how many power unit are available in season.

[hemichromis]

They say the information came from Auto trader?!!

At least the 223bhp rumor was from a spanish reporter who has at least some contact with Alonso's manager.

Also, i prefer the 223 rumor!

[PlatinumZealot]

We can argue until we're blue in the face about who knows what. Look at what actually works, and then tell me why it's wrong?

https://www.youtube.com/watch?v=UxVqWfQZeOQ

Listen to the engine when it's halfway down the straight, does it not sound like it's turbo is stalling?

Radial compressor is almost impossible to stall under a normal working. In the case where even if you slam the throttle shut - and even if there is no blow off, the system is designed for these events by use of the MGUH. Also the pressure ratio is so small when compared to axial compressors.. it's only a few bar haha. I don't think the compressor is stalling at all - even if it were stalling it is only one stage with passages only a few centimeters in length - nothing detrimental will happen like in a multistage axial compressor with rows of blades....

[jure]

I find it amazing, how Honda thinks they can make PU much smaller than other 3 competitors. Mercedes went radical with split turbo to allow for better packaging (and cooler air for ice), Newey has surely pushed Renault hard with regards to packaging and yet Honda thinks they can do much better job. It just seems they want something that can't be done and I wouldn't be surprised at all if they hit troubles. However, it is a good thing they are pushing the boundaries and at least they will learn something.

[hemichromis]

I find it amazing, how Honda thinks they can make PU much smaller than other 3 competitors. Mercedes went radical with split turbo to allow for better packaging (and cooler air for ice), Newey has surely pushed Renault hard with regards to packaging and yet Honda thinks they can do much better job. It just seems they want something that can't be done and I wouldn't be surprised at all if they hit troubles. However, it is a good thing they are pushing the boundaries and at least they will learn something.

They really had to go radical or they would be trying to catch Mercedes from 2 years behind with the same strategy.

The hope is that the Honda method will in the end work best and be hard for mercedes et all to copy.

I'm very hopeful but i know that even if Honda catch Mercedes in power terms they are unlikely to match them with reliability.