Honda Power Unit Hardware & Software

[glenntws]

1-4-5-6-3-2? 1-5-3-6-2-4? 1-4-3-6-2-5? 1-4-2-5-3-6? or 1-2-3-4-5-6?

This is a clue isn't it? Does Honda number their V's per bank or along the crank?

Maybe it really is... The possibility exists and the good thing about that variant is, that you have a good mixture of continuous flow to the turbine and one pulsed one with higher energy.

With 1-2-3-4-5-6, the ignition timing would be:
1 - 120° - 2 - 120° - 3 - 210° - 4 - 120° - 5 - 120° - 6 - 30° - 1

I don't know, how this would work in terms of vibrations. But this firing order is so unorthodox, the more I think about it, the more it seems realistic...

This would also fit to the picture I posted of the RA616H. The exhaust system has a wider main pipe diameter, which is not very much but it could be the increase in flow area they need to fix the huge amount of exhaust flow overlap.

Also, we are all (except from Wazari and his colleague) not familiar with dual-fed exhaust turbines I think. Maybe, if they have one exhaust pipe working at the time and then the other one (360° just with left bank, 90° no flow, 180° just with right bank, 90° with both banks) it doesn't hurt the absolute efficiency of the turbine not as much as a "real" pulse charging.

[glenntws]

Oh, and if you remember the little screenshot of the audio analysis of the idle sound from the teaser video, I mentioned a spacing which would result out of cylinder shutoff and interestingly... The idle sound real fits to the 1-2-3-4-5-6 firing order... Together with cylinder shutoff, the engine was running on cylinders 2,4 and 5, and I'm very sure about that...



The spacing between the ignition events would be 2 - 330° - 4 - 120° - 5 - 270° - 2.
Which fits so exact to the sound...

The sound dampening of the 4&5 cylinder firing which you can hear in the video would result out of the single manifold connected to both these cylinders.

I think Wazari gave us a big hint and we're on a right way in terms of firing order now.

[godlameroso]

Why not 1-6-3-4-2-5, or 1-5-2-4-6-3? Maybe one thing to consider is how much control exists over the actual combustion process. As far as being able to control injection and ignition pulses, and think about how that relates to the different crank firing angles, maybe more crank angle gives you more time to have a more 'thoughtful' combustion.

On a related note, I love Honda engines, they're very well engineered, I just finished mine, and I'm waiting for my laziness to give way before doing the swap.

[PlatinumZealot]

A problem of TJI spark plug nozzles when used with petrol is soot blocking them up.

Interesting. Your source?

http://papers.sae.org/2011-01-1870/

You can click preview to see the paper.

Ok, Seems my memory mislead me a bit. This paperis about passive prechamber sparkplugs NOT the Mahle style with the injector in the pre-chamber. Correct me if I am wrong here, but I can still see soot still being a problem on the Mahle style pre-chamber even if it is just a small depositt, as we assume a richer environment in there? Maybe these spark plug nozzles are changed each race (are they even allowed to be changed?).

[godlameroso]

This resonance business is very interesting indeed, but it's all relative, perhaps a certain firing order creates resonance at low rpm but not at high rpm. Maybe the trick is then finding that sweet spot, where the resonant frequency is cancelled out through most of the important rev range. Say 6-12,500 rpm. You really would need a genius to figure it out though.

Resonance is really just another form of energy, if you could harness it, you could use it to do work.

Maybe a small load can also cancel the resonance at certain frequencies, or make it worse.

Maybe a hydraulic damper can function as a pump, and send energy from damping the resonance at low rpm to the MGU-K.

[glenntws]

A problem of TJI spark plug nozzles when used with petrol is soot blocking them up.

Interesting. Your source?

http://papers.sae.org/2011-01-1870/

You can click preview to see the paper.

Ok, Seems my memory mislead me a bit. This paperis about passive prechamber sparkplugs NOT the Mahle style with the injector in the pre-chamber. Correct me if I am wrong here, but I can still see soot still being a problem on the Mahle style pre-chamber even if it is just a small depositt, as we assume a richer environment in there? Maybe these spark plug nozzles are changed each race (are they even allowed to be changed?).

At first: yes, the spark plug can indeed be changed whenever they want. It's not included in the rule for PU changes, and it's not sealed.

But while there definetly could be a soot problem, I don't think that it's as critical as you may think. The fuel regulations do not Limit the amount of used Methanol, Ethanol or other very short molecules. I'm very sure that - even though also high-energy components with longer carbon chains are used to boost energy per mass - the fuel is to a big part a mixture of ethanol and methanol.

Burning ethanol and methanol in a high turbulence chamber makes up for a low amount of soot. Also, I don't think the pre-chamber is as bad as many may think. You have to remember: The air that is pushed into this pre-chamber generates a huge amount of charge motion and when this mixture get's ignited and the only room where the gases can expand into are these little holes, you have extreme conditions where also very long molecules are just cracked up and seperate into smaller molecules.

Because of that, I think that the soot problem is not as bad as many may think.

[PlatinumZealot]

•Does the turbine benefit more from six evenly (as possible) spaced exhaust pulses, or fewer, larger pulses? Previous seasons showed us tuned length headers, so presumably thae answer at least used to be "six." Perhaps MGUH could 'torque fill' between bigger pulse-gaps.

Maximum number of evenly spaced exhaust pulses sharing an exhaust manifold without loss of blowdown energy is three. That is why the turbines have two entry ports with three cylinders feeding each. Using a 120 deg crank, each bank becomes an even-firing 3 cylinder which simplifies the plumbing - one bank feeds each turbine entry.

Gotcha, thanks. That true of the Merc, definitely. However the Renaults, 2014 at least, had single entry.

https://pbs.twimg.com/media/C40MgsjXAAAdEFT.jpg

My main point is, is the turbine adversley affected by fewer, larger pulses? I'm imaging operating the V6 as a V-twin, firing an entire bank at once. The resulting three-cylinder exhaust pulse might get some heat retention benefits through the shared portion of the exhaust system. A larger pulse should dissipate heat for a longer period of time & conduction through the manifold wall is also time constrained. But I wonder if more constant flow is preferable for turbine operation than more intermittent, hotter flow.

Single flange. But it was stil twin scroll. Still two entries.

[roon]

Looks like a single scroll. You'd think an F1 housing would be thin walled enough to discern the internal geometry from the exterior.

[Tommy Cookers]

......The fuel regulations do not Limit the amount of used Methanol, Ethanol or other very short molecules. I'm very sure that - even though also high-energy components with longer carbon chains are used to boost energy per mass - the fuel is to a big part a mixture of ethanol and methanol.

3 years ago this forum seemed to agree that even the mandated 5.7% biofuel content would not be ethanol or methanol
why would anyone use these (beyond the 5.7%) ?

a bio-isobutanol feedstock would be used to make a biofuel-qualifying component with a heating value close to the non-bio content's HV

[PlatinumZealot]

Looks like a single scroll. You'd think an F1 housing would be thin walled enough to discern the internal geometry from the exterior.

https://i.imgur.com/SPXoM1Yh.jpg

Isn't that just blank represenation of the volume of the turbine though?
Two pipes enter here so it sort of mad not to make the turbine twin scroll.

[roon]

I don't know. I'm just interpreting the image. Two pipes joining prior to the single entry doesn't guarantee twin scroll, and the scroll in the other image lacks the telltale double-bump profile of a twin scroll housing.

[PlatinumZealot]

1-4-5-6-3-2? 1-5-3-6-2-4? 1-4-3-6-2-5? 1-4-2-5-3-6? or 1-2-3-4-5-6?

The first one:
3-2-1-4-5-6

Edit*

This order does not work with normal v6 cranshaft... Adds more than 720 degrees.


The second one
1-5-3
6-2-4
I think BMW has this pattern in their straight sixes. So since the f1 honda is v6 this is strange because cylinder 3 and 6 to be on the same journal and since you have 6 following 3 and 1 following four that mean this engine will not make two cycles within 720 degrees.. You need 990 or 1080 degrees.. So it would have dead strokes there. So this firing oder only works on a straight six.

Have to look on the other two later.

Edit:
The third order of 1-4-3-6-2-5 is uneven 90-150 degrees firing but is ok It fits into 720 degrees.

The fourth one of 1-4-2-5-3-6. Is like the previous mentioned firing order ony the crankshaft would be a mirror image of the 1-4-3-6-2-5 crank.

1-2-3-4-5-6 firing order... Would work but would have an abnormally small interval between the firing of 6 going to 1.

So only the third and fourth i have working here otherwise there is a trick crankshaft or my maths wrong.

[Roostfactor]

roon wrote
I have a feeling Honda have created a monster.

I agree, the audio clip wasnt the best but I think it sounds aggressive at idle. My gut tells me HRD created a beast! Tuning, reliability, and ironing out the inevitable kinks I think will be the big factor.

Also, many thanks to Wasari san for his broad guideance. Its brilliant how he gives us open ended insight without giving away much coveted secrets!

Obviously there are many extremely intelligent people on here...I really enjoy reading your opinions and gaining insight on potential configurations.

John

[glenntws]

1-4-5-6-3-2? 1-5-3-6-2-4? 1-4-3-6-2-5? 1-4-2-5-3-6? or 1-2-3-4-5-6?

The first one:
3-2-1-4-5-6

Edit*

This order does not work with normal v6 cranshaft... Adds more than 720 degrees.


The second one
1-5-3
6-2-4
I think BMW has this pattern in their straight sixes. So since the f1 honda is v6 this is strange because cylinder 3 and 6 to be on the same journal and since you have 6 following 3 and 1 following four that mean this engine will not make two cycles within 720 degrees.. You need 990 or 1080 degrees.. So it would have dead strokes there. So this firing oder only works on a straight six.

Have to look on the other two later.

Edit:
The third order of 1-4-3-6-2-5 is uneven 90-150 degrees firing but is ok It fits into 720 degrees.

The fourth one of 1-4-2-5-3-6. Is like the previous mentioned firing order ony the crankshaft would be a mirror image of the 1-4-3-6-2-5 crank.

1-2-3-4-5-6 firing order... Would work but would have an abnormally small interval between the firing of 6 going to 1.

So only the third and fourth i have working here otherwise there is a trick crankshaft or my maths wrong.

Like I said, third, fourth and last option are the only ones that make sense. But I would exclude the fourth because it's just the thrids but with a worse power Distribution over the crankshaft. Everything else is the same.

The sixth is unorthodox but damn, it fits to the idle sound.

See here what I meant:

Oh, and if you remember the little screenshot of the audio analysis of the idle sound from the teaser video, I mentioned a spacing which would result out of cylinder shutoff and interestingly... The idle sound real fits to the 1-2-3-4-5-6 firing order... Together with cylinder shutoff, the engine was running on cylinders 2,4 and 5, and I'm very sure about that...



The spacing between the ignition events would be 2 - 330° - 4 - 120° - 5 - 270° - 2.
Which fits so exact to the sound...

[PlatinumZealot]

Ok. Do you think that wazari gave us ALL of the firing orders that the engine uses for various reasons? Whether it is warm up, cool down, or some other strange reasons?

In the video where jenson pulled out of the garage the engine seemed to change from that weird tone to a more regular one.

Could it be an on-the-fly change in firing order?

And just being a little crazy here: The other firing orders Wazari listed with the "dead cylinders" the ones having a a complete of 1080 degrees. Could these firing orders be a form of cylinder deactivation? Instead of one ingition event in 720 degrees. It is instead two ignition events in 2160 degrees. In effect one vacuous or missing power stroke in every three normal cycles.

This could be used under braking maybe?
Or lift and coast?
Or for exhaust gas recirculation(the exhaust from the other active cylinders would easily flow into the "dead" ones?