Honda Power Unit Hardware & Software

[Brian Coat]

Maybe I've read too many conspiracy theory novels but I'm thinking that the real stuff in the Honda/NHK video (engine bits, data screens) are the fuzzed out ones and the ones we can see are fake / tweaked.

What team would be daft enough to show real critical parts images and real critical data, mid-season unless obliged to do so?

[dren]

Thanks @Dren for that link,Omnicorse said recently that it will be 15Bhp but it is Omnicorse after all.
Allen is a bit more reaible i would say.

James Allen reliable?
Arai said 15hp.

He typically is pretty reliable with the 'rumors' and 'mumblings' going on track side. When it comes to 'rumors' I tend to trust his more than most. But take it for what you will.

[ringo]

The british guys will say 50hp so as to not put most of the blame on the chassis for the performance, and the Japanese guys will say 15hp, to show that if there are no reliability issues it's the chassis and energy management.

[ringo]

I have inputted the high a:f into my calculator, and ive realized that Honda's engine cannot be used as a prime example. There is a great power loss when compared to stoichometry. The flame temperature in the cylinder just too low. I notice high boost is used momentarily, it may be some fuel saving tactic, but high a:f doesn't really have any theoretical advantage, it must be some real life occurrence in the cylinders that may have been referred to in the engine thread.
Honda's engine is underpowered, and maybe they are just doing things a bit differently with their unit. It would be good to see data from a mercedes or ferrari engine.

[trinidefender]

I have inputted the high a:f into my calculator, and ive realized that Honda's engine cannot be used as a prime example. There is a great power loss when compared to stoichometry. The flame temperature in the cylinder just too low. I notice high boost is used momentarily, it may be some fuel saving tactic, but high a:f doesn't really have any theoretical advantage, it must be some real life occurrence in the cylinders that may have been referred to in the engine thread.
Honda's engine is underpowered, and maybe they are just doing things a bit differently with their unit. It would be good to see data from a mercedes or ferrari engine.

How did you alter the a:f ratio? Of course reducing the fuel flow will create lower in cylinder temps and hence pressure. However leaving the fuel flow the same at 100kg/hr and increasing airflow to increase a:f ratio should not lower the temp that much.

How can it be some fuel saving tactic? The whole formula is that a more efficient engine produces more power.

I'm not so sure that your calculator can work out the additional variables created by stratified injection combustion.

[pgfpro]

I have inputted the high a:f into my calculator, and ive realized that Honda's engine cannot be used as a prime example. There is a great power loss when compared to stoichometry. The flame temperature in the cylinder just too low. I notice high boost is used momentarily, it may be some fuel saving tactic, but high a:f doesn't really have any theoretical advantage, it must be some real life occurrence in the cylinders that may have been referred to in the engine thread.
Honda's engine is underpowered, and maybe they are just doing things a bit differently with their unit. It would be good to see data from a mercedes or ferrari engine.

The reason I think its so is because as you approach the upper rpm fuel limit you can load the turbo with the MGUH and lean the A/F ratio and pull more energy from the turbo. If you run it full rich you will be hitting the fuel limit at a lower boost with less energy. The difference from my calculations are about 20HP.

In my above quote my reference to lean out the A/F ratio, I didn't state what the A/F ratio is? In my calculations and sims I'm talking no more then stoich up to 16:1 A/F ratio being max. Any leaner as you stated you start losing exhaust temperature.

So I think they are running full power rich and as they approach the higher rpm before they up shift is when they could get the most output from the turbine by running stoich or a little leaner then stoich.

[Abarth]

Don't know about the Drive section but:

81376 rpm should be Turbo rpm
2.29 bar should be Charge Air Pressure
TExl should be Exhaust temperature of the left Cylinder Bank
TExr same on the right hand side

The other 2 could be Fuel usage.

I'm trying to find exhaust back pressure on the telemetry but can't see it? I would think they would have it right with the turbo outputs? It should shadow the intake boost numbers to some degree until they load the turbo for more MGUH energy.

Are we sure that the 2.29 bar are charge air pressure?
Could well be backpressure too...

[RicME85]

"I am confident that our reliability problems are now behind us which means we can turn our attention to increasing power," Honda boss Yasuhisa Arai said. "After the summer shutdown our plan is to apply a new-spec engine using some of our remaining seven tokens.

"The most important area for us to concentrate on is the combustion. Current regulations require high efficiency of the combustion so we want to change the characteristic with the chamber design and intake and exhaust system layout. Another issue we will be addressing is reducing mechanical friction by changing the gear train system along with the combustion.

"Not all of our upgrades will be in place for the Belgium Grand Prix; some parts will be applied for Spa and the rest during the weeks that follow. Our plan is to keep improving race-by-race for the remainder of the season."

[ringo]

How did you alter the a:f ratio? Of course reducing the fuel flow will create lower in cylinder temps and hence pressure. However leaving the fuel flow the same at 100kg/hr and increasing airflow to increase a:f ratio should not lower the temp that much.

How can it be some fuel saving tactic? The whole formula is that a more efficient engine produces more power.

I'm not so sure that your calculator can work out the additional variables created by stratified injection combustion.

I can alter A:F and stick to max permitted fuel flow at the specified rpm. I didn't reduce the fuel flow, but as a result of the increase mass of air, the combustion temperatures will drop. The engine is not necessarily more efficient if there are increased pumping loses either. Your thermal efficiency loss is mostly in combustion.
I think the disconnect here is in the in-cylinder conditions at combustion. I use software to figure out these conditions. The software assumes homogeneously mixed fuel and air. So 16:1 mix is assuming homogeneously mixed fuel. I suppose with direct injection it may have different A:F at localized areas in the cylinder. If that's the case it is beyond what i can predict. I simply cannot speak to that then.

No my calculator cannot work out the additional variables created in the cylinder during combustion (it depends on an output from a combustion software that doesn't have any direct injection features) . But who here can?

[ringo]

I have inputted the high a:f into my calculator, and ive realized that Honda's engine cannot be used as a prime example. There is a great power loss when compared to stoichometry. The flame temperature in the cylinder just too low. I notice high boost is used momentarily, it may be some fuel saving tactic, but high a:f doesn't really have any theoretical advantage, it must be some real life occurrence in the cylinders that may have been referred to in the engine thread.
Honda's engine is underpowered, and maybe they are just doing things a bit differently with their unit. It would be good to see data from a mercedes or ferrari engine.

The reason I think its so is because as you approach the upper rpm fuel limit you can load the turbo with the MGUH and lean the A/F ratio and pull more energy from the turbo. If you run it full rich you will be hitting the fuel limit at a lower boost with less energy. The difference from my calculations are about 20HP.

In my above quote my reference to lean out the A/F ratio, I didn't state what the A/F ratio is? In my calculations and sims I'm talking no more then stoich up to 16:1 A/F ratio being max. Any leaner as you stated you start losing exhaust temperature.

So I think they are running full power rich and as they approach the higher rpm before they up shift is when they could get the most output from the turbine by running stoich or a little leaner then stoich.

Ok i see.

[trinidefender]

Here is a question for those more versed in the chemistry side of fuel than me.

We are talking about stoichiometric and trying to figure out the most efficient a:f ratio. For normal road car petrol I know stoichiometry to be about 14.5:1 - 14.7:1. How much can the change in chemistry of these fuels affect stoichiometry. What I mean by that is what if the stoichiometric ratio for these fuels is 15.5:1.

If that were to be the case then the engines would be running more rich (or maybe less lean) than we thought. The opposite being true if the stoichiometric a:f ratio is lower than that of regular road car petrol.

[Tommy Cookers]

the stoichiometric mass (if nothing's unavailable for combustion) is apparently due only to the proportion of hydrogen to carbon ?
eg pentane is C5H12 and its stoichiometric mass ratio is 15.22
dodecane ( a typical major constituent of gasoline) is C12H26 and its SMR is 14.88 (makes sense)
benzene is (similar to distinctive constituents of 100/130 Avgas) is C6H6 and its SMR is 13.25 (why Avgas SMR is a bit low)

a higher ratio of hydrogen to carbon gives (ignoring eg double bonds) a higher mass-specific calorific value, a prime requirement

I don't see that this takes us anywhere startling, though

[trinidefender]

the stoichiometric mass (if nothing's unavailable for combustion) is apparently due only to the proportion of hydrogen to carbon ?
eg pentane is C5H12 and its stoichiometric mass ratio is 15.22
dodecane ( a typical major constituent of gasoline) is C12H26 and its SMR is 14.88 (makes sense)
benzene is (similar to distinctive constituents of 100/130 Avgas) is C6H6 and its SMR is 13.25 (why Avgas SMR is a bit low)

a higher ratio of hydrogen to carbon gives (ignoring eg double bonds) a higher mass-specific calorific value, a prime requirement

I don't see that this takes us anywhere startling, though

What I am getting at is that many here are all arguing cases for and against running anything from stoichiometric to quite lean. The problem I see with that is that we are basing this (air mass flow numbers obtained through pressure ratios and temperatures) off of calculations used for working out stoichiometry for normal car petrol.

Most likely the fuel that each engine manufacturer uses will have a slightly different stoichiometric ratio. To add to that I wouldn't be surprised to see that the fuels that each engine design runs has a stoichiometric ratio quite different enough to road car petrol that it may be adding in errors in our calculations that are worth talking about.

P.s. Sorry for the horrible sentence structure, tired and just got home from work.

[Brian Coat]

I think you are right, there will be such an effect.

For example, I interpret the combination of rules 19.4.3 thru 19.4.5 as effectively mandating 5.75 pct. alcohol or similar? Correct me if I'm wrong.

In normal gasoline 5.75% alcohol would typically shift stoich AFR by say .4 richer AFR and also reduce LHV by say 1 MJ/kg???

The oxygenates will also increase the knock limit so some power lost through reduced LHV could be recovered through higher PR?

19.4.3 The only oxygenates permitted are paraffinic mono-alcohols and paraffinic mono-ethers with a final boiling point below 210°C.
19.4.4 A minimum of 5.75% (m/m) of the fuel must comprise bio-components.
19.4.5 Initially the bio-components are restricted to oxygenates. However, hydrocarbons (as defined in 19.2) and oxygenates (lying outside the 19.4.3 definition) or mixtures thereof, which have been produced from biomass, may be included in Formula One fuel as part of the 5.75% biocomponents quota, provided that a suitable analytical procedure is available for their quantification and to verify their biological origin. Their use in F1 fuel will be dependent on evidence indicating that the supplier is genuinely developing these compounds for use in commercial fuels.

[Tommy Cookers]

under 19.4.5 as the bio 5.75% they will be using fuel with near-normal calorific value etc (ie not ethanol)
(bio) Isobutanol is the bio precursor from which this 5.75% will be made
there is pilot scale production widely
it's the same feedstock from which lots of hydrocarbon was made in WW2, but now from a bio (eg bacterial) process
(Isobutanol used 'as is' has 15% better calorific value than ethanol, but can be made into diesel and gasoline type fuels)

NOTE TO SELF
ERC A 19A was the best current gasoline found - at 47 MJ/kg UCV - so only 44 MJ/kg LCV