Honda Power Unit Hardware & Software

[n4rf]

Seems a transient or part load condition.
Interestingly enough, the fuel pressure is 300 bar. I thought Honda was adopting pump/injectors with 500 bar capability (the limit of the regulations).

Everything else we hear about 500 bar in the 2015 Mercedes has not been confirmed yet so it is a bit of a crapshoot. This could also be a very old screen too. Honda might have upgraded to 500 bar since then. Again we have not confirmation of this... so it anyone's guess.

Another interesting thing is the flow into the fuel flow meter is different from the flow through the injectors. I guess it depends on how they integrate the instantaneous values.

The fuel is hot too. 70 deg as someone else pointed out. I think this temperature rise is from pumping the fuel and heat transfer from the cylinder head?

The fuel pressure is probably variable. You won't see 500 bar at part load.

Hot fuel is deliberate (as I have suspected for some time). If they are running at 70* it is because the engine is more efficient at that temperature - not because they cannot control the fuel temperature. Fuel "heaters" were dicussed in another thread (the one about FIA clamping down on secret fuel accumulation and changing system pressure).

Interesting that the power at 10,000 rpm is the same as the Honda RA168e - just coincidence?

How do you come to the conclusion, that the engine is more efficient with higher fuel temperatures?
Especially for DI engines it also matters a lot where you measure it. If that's inside the fuel cell I'd say that's rather hot. On the other hand you get packaging advantages and if you design your pumps and injectors accordingly it shouldn't be an issue.

[Blackout]

Honda MGU-K mistake.

https://pbs.twimg.com/media/CO4-vO9WsAEB_2x.jpg:large

Yes, my fault, I compared many pics and the Honda MGuK looks a lot smaller than the Renault and Ferrari.

The air filter surface in the air intake is a lot smaller than all the other engines too...

[trinidefender]

595 HP @ 10000 rpm Does that mean 725@12000???

http://i1267.photobucket.com/albums/jj5 ... 3b3xbj.jpg

Does anybody know what the fuel flow limit at the rpm shown (9894rpm) would be?

If you were to assume a flat torque curve from 9894rpm as shown to 10500rpm then that would equal 630 hp at the max fuel flow limit of 10500rpm. If the fuel flow can be greater at 10500rpm than at 9894rpm then you should expect more power than that

[Blackout]

Mass flow can't exceed Q (kg/h) = 0.009 N(rpm)+ 5.5. So fuel flow at that rpm should be 94.5
one second...

[Blackout]

IMO, if thermal efficiency = 40, power would be 629hp when we reach 100kg/h fuel flow

[trinidefender]

Thanks for the fast reply blackout.

Well using a figure of 631 hp at 10500rpm (figure obtained by calculation in previous post) then if you increase hp linearly compared to a fuel flow increase of 94.546 kg/h to 100kg/h then you get about 667 hp at 10500rpm.

Notes:
1. Data obtained from image posted by WilliamsF1 showing 428Nm of torque at 9894rpm.
2. Assumption made by me that torque curve is flat from 9894rpm to 10500rpm (when using a constant fuel flow).
3. Assumption by me that torque will scale linearly with an increase of fuel flow.
4. Using as accurate numbers as my pocket calculator will all equals to 631hp at the fuel flow allowed at 9894rpm (95.546kg/h)
5. I made no allowances for friction increases going from 9894rpm to 10500rpm.

Notes 2 and 3 will be the largest contributors to any errors that may have formed in my calculations.

Thoughts?

[trinidefender]

IMO, if thermal efficiency = 40, power would be 629hp at 100kg/h fuel flow

Mind telling what energy content for the fuel that used?

[Blackout]

Sorry, I forgot: 42MJ/K
Edit: but 43 is more correct IMO

[Tommy Cookers]

Thanks for the fast reply blackout.
Well using a figure of 631 hp at 10500rpm (figure obtained by calculation in previous post) then if you increase hp linearly compared to a fuel flow increase of 94.546 kg/h to 100kg/h then you get about 667 hp at 10500rpm.
Notes:
1. Data obtained from image posted by WilliamsF1 showing 428Nm of torque at 9894rpm.
2. Assumption made by me that torque curve is flat from 9894rpm to 10500rpm (when using a constant fuel flow).
3. Assumption by me that torque will scale linearly with an increase of fuel flow.
4. Using as accurate numbers as my pocket calculator will all equals to 631hp at the fuel flow allowed at 9894rpm (95.546kg/h)
5. I made no allowances for friction increases going from 9894rpm to 10500rpm.
Notes 2 and 3 will be the largest contributors to any errors that may have formed in my calculations.
Thoughts?

2 at least is mistaken ?? (unless I misunderstand the wording or something else that's been done)

we can only assume that power (energy/time) is proportionate to fuel rate ie fuel/time
ie a flat torque curve (ie constant torque) from 9894 rpm to 10500 rpm cannot be obtained using a constant fuel flow (fuel/min)
constant torque (aka 'flat torque curve') comes from constant fuel/rev not constant fuel/min
and so FTC to 10500 from 9894 requires 10500/9894 fuel/min increase in fuel rate

btw
we know that a prominent team says that it uses fuel of 44.64 MJ/kg LCV
and another team has atributed recent substantial power gains to fuel improvement

[turbof1]

Mr. Facts, you were not adressing me I know, but with 6 months to go don't you think the scatter-gun approach is still a good one? I don't think it is slow though. Remember Porsche used a scatter gun approach in designing the 919 engine and that worked out well. Just keep the faith I say.

PZ, this is unfortunaly not WEC. WEC has relative open development regulations concerning the engine/power unit. Furthermore, 10 open private tests and 10 closed private tests are allowed, with new entrants having an additional 10 days to their disposal. Porsche had 30 test days and open engine development to their disposal when they entered WEC. Best of all: Porsche could choose whenever they wanted to use those test days.

Honda does not have that luxury. It had 3 weeks testing during winter and after that not a single oppertunity to test out different engine configurations. Scatter shot implies you can experiment and test out at leasure, which simply is not an option in F1: either you get it right at the beginning of the season, or you don't and you are at the very least stuck until the next season, which also features only 2 weeks of testing to add insult to injury.

I don't want to drag this further down the pit, because this is a car thread, but F1 is entry-unfriendly. Besides the large costs, you also don't have any room for improvement. F1 has alienated itself in that regard, so for Honda to enter this kind of sport is a huge act of courage on it self.

[Wazari]

2 at least is mistaken ?? (unless I misunderstand the wording or something else that's been done)

we can only assume that power (energy/time) is proportionate to fuel rate ie fuel/time
ie a flat torque curve (ie constant torque) from 9894 rpm to 10500 rpm cannot be obtained using a constant fuel flow (fuel/min)
constant torque (aka 'flat torque curve') comes from constant fuel/rev not constant fuel/min
and so FTC to 10500 from 9894 requires 10500/9894 fuel/min increase in fuel rate

btw
we know that a prominent team says that it uses fuel of 44.64 MJ/kg LCV
and another team has atributed recent substantial power gains to fuel improvement

Yes you are correct, Mr. Cookers.

[gruntguru]

Everything else we hear about 500 bar in the 2015 Mercedes has not been confirmed yet so it is a bit of a crapshoot. This could also be a very old screen too. Honda might have upgraded to 500 bar since then. Again we have not confirmation of this... so it anyone's guess.

Another interesting thing is the flow into the fuel flow meter is different from the flow through the injectors. I guess it depends on how they integrate the instantaneous values.

The fuel is hot too. 70 deg as someone else pointed out. I think this temperature rise is from pumping the fuel and heat transfer from the cylinder head?

The fuel pressure is probably variable. You won't see 500 bar at part load.

Hot fuel is deliberate (as I have suspected for some time). If they are running at 70* it is because the engine is more efficient at that temperature - not because they cannot control the fuel temperature. Fuel "heaters" were dicussed in another thread (the one about FIA clamping down on secret fuel accumulation and changing system pressure).

Interesting that the power at 10,000 rpm is the same as the Honda RA168e - just coincidence?

How do you come to the conclusion, that the engine is more efficient with higher fuel temperatures?
Especially for DI engines it also matters a lot where you measure it. If that's inside the fuel cell I'd say that's rather hot. On the other hand you get packaging advantages and if you design your pumps and injectors accordingly it shouldn't be an issue.

Hot fuel improves engine efficiency as follows:
- Increases flame speed
- Reduces cycle-to-cycle variability
- Increases lean ignition limit

http://www.k20a.org/upload/HondaRA168EEngine.pdf Page 7, Fig 13 optimum fuel temp was 80*C.

As in the RA168e, the fuel in the cell would not be heated - heating would be just prior to injection.

Fuel heating is standard practice in modern, common rail diesels.

[trinidefender]

2 at least is mistaken ?? (unless I misunderstand the wording or something else that's been done)

we can only assume that power (energy/time) is proportionate to fuel rate ie fuel/time
ie a flat torque curve (ie constant torque) from 9894 rpm to 10500 rpm cannot be obtained using a constant fuel flow (fuel/min)
constant torque (aka 'flat torque curve') comes from constant fuel/rev not constant fuel/min
and so FTC to 10500 from 9894 requires 10500/9894 fuel/min increase in fuel rate

btw
we know that a prominent team says that it uses fuel of 44.64 MJ/kg LCV
and another team has atributed recent substantial power gains to fuel improvement

Yes you are correct, Mr. Cookers.

Thought it over for about 2 seconds and realised the stupidity of what I wrote.

That will mean if you have a linear power increase from the increase in fuel flow at 10500rpm then the ICE should produce about 631 hp. Sound like a fair estimate? This is all going on the information contained in the screengrab

[Wazari]

2 at least is mistaken ?? (unless I misunderstand the wording or something else that's been done)

we can only assume that power (energy/time) is proportionate to fuel rate ie fuel/time
ie a flat torque curve (ie constant torque) from 9894 rpm to 10500 rpm cannot be obtained using a constant fuel flow (fuel/min)
constant torque (aka 'flat torque curve') comes from constant fuel/rev not constant fuel/min
and so FTC to 10500 from 9894 requires 10500/9894 fuel/min increase in fuel rate

btw
we know that a prominent team says that it uses fuel of 44.64 MJ/kg LCV
and another team has atributed recent substantial power gains to fuel improvement

Yes you are correct, Mr. Cookers.

Thought it over for about 2 seconds and realised the stupidity of what I wrote.

That will mean if you have a linear power increase from the increase in fuel flow at 10500rpm then the ICE should produce about 631 hp. Sound like a fair estimate? This is all going on the information contained in the screengrab

I would say that's fair. Of course all based on linear power increase which is always not often the case. It is my understanding that the engine is producing about 625 HP at 10,650 RPM.

[Tauri_J]

Fuel heating is standard practice in modern, common rail diesels.

then why BMW diesel's have a fuel cooler?