Honda Power Unit Hardware & Software

[Midnight]

https://youtu.be/ODGPhiQasdM


Listen @1 min 11 sec

[gruntguru]

When using something like TJI, you have a effect that is very much comparable to HCCI combustion. The pressure in the cylinder rises dramatically faster than before becuase combustion is finished much earlier. Now, you have a longer time with hot gases wanting to expand and loose their energy in the cylinder than before and the transfer of heat to the walls happens more intensively, thus the energy efficiency of the ICE gets much higher, while the energy that is left in the exhaust gases get's lower.

You might want to check the bit in red. More loss to the walls results in lower energy efficiency.

Faster combustion is win, win.
The obvious benefit is early peak-pressure and temperature so a greater % of the stroke is available to expand the burnt gas.

Less obvious is that peak temperature coincides with a smaller chamber volume - a much smaller portion of the cylinder is exposed to the hottest gas - in particular very little of the cooler, lower sections of the bore. Win again.

The section of bore above the top ring travel can be run much hotter because lubrication is not required. Hot surfaces accept less heat from the gas so its win again.

Finally - the ultra-lean mixtures made possible by TJI mean lower gas temperatures at all points of the power stroke - again less heat loss to the cylinder. Lower exhaust temperature of course means less energy for the turbine, but this compensated by the higher pressure and higher mass flow associated with high boost, ultra lean operation.

[gruntguru]

well, my guess is that .......
combustion gets slower with leaner mixtures (and combustion slowing and combustion becoming less efficient go hand-in-hand)
?

Nope Lean burn combustion is faster. Which is part of the reason there is less heat in the exhaust path compared to a more traditional burn. It is well known that proper lean burn cycles produce lower exhaust temps. My guess the faster combustion means the charge has had more time to cool prior to the exhaust stroke beginning.

Nope. Lean burn combustion is slower. TJI is faster.

[gruntguru]

https://youtu.be/ODGPhiQasdM
Listen @1 min 11 sec

NIce example of some serious cylinder skipping at part load.

[henry]

It's today
https://www.youtube.com/watch?v=4-73NA0 ... e=youtu.be

An underpowered PU don't do that kind of wheel spin.

Thats not true at all! Those engines produce >900 bhp with insane amount of torque. More than enough for any kind of wheel spin.

Last year they could wheelspin at any speed up to 160kph in a straight line (up to that speed they couldn't use WOT) . This year with higher downforce and more tyre that might come down to around 120kph.

[PlatinumZealot]

People need to stop perpetuating the vortex exhaust idea. It is not realistic from a heatloss, flow or fabrication side. Ceramic coating achieves all it needs to. The biggest heat loss is in the ICE itslelf. So please stop perpetuating this crazyness.

[godlameroso]

In science nothing is impossible only improbable.

If life has taught me anything, there's always some aspect you weren't thinking about that makes something work, or not work.

Whenever I hear someone say "that won't work" it seems like an unfinished phrase. It should really say, "that won't work with the current philosophy or method we are following", but then people's hesitation to change the status quo would reveal itself, and status would be lost, and all the negative social consequences of having to start over.

A very tall but not very wide wall is only insurmountable if you only look up.

[glenntws]

When using something like TJI, you have a effect that is very much comparable to HCCI combustion. The pressure in the cylinder rises dramatically faster than before becuase combustion is finished much earlier. Now, you have a longer time with hot gases wanting to expand and loose their energy in the cylinder than before and the transfer of heat to the walls happens more intensively, thus the energy efficiency of the ICE gets much higher, while the energy that is left in the exhaust gases get's lower.

You might want to check the bit in red. More loss to the walls results in lower energy efficiency.

Faster combustion is win, win.
The obvious benefit is early peak-pressure and temperature so a greater % of the stroke is available to expand the burnt gas.

Less obvious is that peak temperature coincides with a smaller chamber volume - a much smaller portion of the cylinder is exposed to the hottest gas - in particular very little of the cooler, lower sections of the bore. Win again.

The section of bore above the top ring travel can be run much hotter because lubrication is not required. Hot surfaces accept less heat from the gas so its win again.

Finally - the ultra-lean mixtures made possible by TJI mean lower gas temperatures at all points of the power stroke - again less heat loss to the cylinder. Lower exhaust temperature of course means less energy for the turbine, but this compensated by the higher pressure and higher mass flow associated with high boost, ultra lean operation.

Maybe I explained it unclear. What you're saying is totally right. The effect is just that combustion happens much faster and by that, the time where the gases can "relax" and cool down is higher. This way, more energy is transferred to the piston and less into the exhaust.

[RS200E]

https://youtu.be/ODGPhiQasdM
Listen @1 min 11 sec

NIce example of some serious cylinder skipping at part load.

Is that a bad thing? (I genuinely dont know). I've heard even the Merc doing that though.

[glenntws]

https://youtu.be/ODGPhiQasdM
Listen @1 min 11 sec

NIce example of some serious cylinder skipping at part load.

Is that a bad thing? (I genuinely dont know). I've heard even the Merc doing that though.

No, it's simply the PU-strategy from Honda to use cylinder shutoff under low/part load conditions. Sound a bit weird or different to other engines but it's perfectly fine. Maybe the other's just have other ideas then cylinder shutoff or whatever

[PlatinumZealot]

Wazari is missing when we need to hear from him the most. What is the atmosphere in sakura Wazari?

?

[Roostfactor]

Wazari is missing when we need to hear from him the most. What is the atmosphere in sakura Wazari?

?

He is probably either super busy or doesnt want to post as many people would blast him with the current growing pains Honda is having. I dont blame him for not posting and feel its unfortunate people cant just take the technical info provided and learn from it.
A brand new unit is bound to have growing pains.

[RS200E]

NIce example of some serious cylinder skipping at part load.

Is that a bad thing? (I genuinely dont know). I've heard even the Merc doing that though.

No, it's simply the PU-strategy from Honda to use cylinder shutoff under low/part load conditions. Sound a bit weird or different to other engines but it's perfectly fine. Maybe the other's just have other ideas then cylinder shutoff or whatever

Thanks ☺

[Wazari]

My inbox has been flooded. Sorry can not answer you all but seems centered on a few things.

1. Yes I am extremely busy. People can bash away. Everyone is entitled to their opinions.
2. I have been asked as others too, not to comment on any status as to specific problems or items. In general, mood at Sakura is very good, believe it or not. Many expected and unexpected setbacks but it appears nothing major. As I mentioned to others via PM, oil scavenging issue was under heavy braking, why this became an issue, I don't know, obviously either a design issue or manufacturing issue.
3. Is Sasha real??? Haha. I will say this, he knew the owner's name of a small restaurant in Sakura where the locals go that's been there since the '60's and completely off the grid. Also knew of the small grocery, convenience store up the hill behind the restaurant that unless you were a local and have been to Sakura, you would never know about it. The road isn't on the map. It's seems strange to me, all these people asking about him lately???
4. I am still excited about this season. I am optimistic, anxious and happy with the new PU. Spec 0.8, 0.9, 1.0 and 1.1.

Best wishes everyone.

[Roostfactor]

My inbox has been flooded. Sorry can not answer you all but seems centered on a few things.

1. Yes I am extremely busy. People can bash away. Everyone is entitled to their opinions.
2. I have been asked as others too, not to comment on any status as to specific problems or items. In general, mood at Sakura is very good, believe it or not. Many expected and unexpected setbacks but it appears nothing major. As I mentioned to others via PM, oil scavenging issue was under heavy braking, why this became an issue, I don't know, obviously either a design issue or manufacturing issue.
3. Is Sasha real??? Haha. I will say this, he knew the owner's name of a small restaurant in Sakura where the locals go that's been there since the '60's and completely off the grid. Also knew of the small grocery, convenience store up the hill behind the restaurant that unless you were a local and have been to Sakura, you would never know about it. The road isn't on the map. It's seems strange to me, all these people asking about him lately???
4. I am still excited about this season. I am optimistic, anxious and happy with the new PU. Spec 0.8, 0.9, 1.0 and 1.1.

Best wishes everyone.

Thank you sir. Now back to work...races coming soon! [-o<