Honda Power Unit Hardware & Software

[dren]

2 points from pre-chamber jet injection and 3 points from HERS, less energy loss to cooling system and turbo design.

50% total

I'd assume that's all on pump gas. Impressive.

[saviour stivala]

So anyone know of what has been changed, new power units for Gasly and for Brendon's car on Friday. As per Tanabe san

https://twitter.com/HondaRacingF1/statu ... 82880?s=19

USA GP FPI Gasly: new ICE, new turbocharger, new MGU-H, new MGU-K. Hartley for FP3: new ICE, new turbochager, new MGU-H, new MGU-K.

[saviour stivala]

In F1 must use only one injector so that injector must be very advance multi-spray.In a production street car, two injectors would be better(even in F1).

Not only the rules stipulate “only one injector per cylinder” but also the injection must be “direct injection”. An injector injecting in a pre-combustion chamber is not a direct injection system.

[godlameroso]

In F1 must use only one injector so that injector must be very advance multi-spray.In a production street car, two injectors would be better(even in F1).

Not only the rules stipulate “only one injector per cylinder” but also the injection must be “direct injection”. An injector injecting in a pre-combustion chamber is not a direct injection system.

How do you figure that? DI means an injector in the combustion chamber does it not?

[trinidefender]

In F1 must use only one injector so that injector must be very advance multi-spray.In a production street car, two injectors would be better(even in F1).

Not only the rules stipulate “only one injector per cylinder” but also the injection must be “direct injection”. An injector injecting in a pre-combustion chamber is not a direct injection system.

Since the pre-combustion chamber is situated in the combustion chamber then it can still be considered direct injection. It's a grey area, you haven't yet identified a rule that excludes a pre-combustion chamber.

Or better yet what if the pre combustion chamber is physically part of the fuel injector? Is there any rule that states that the injector can't have a cavity in it? In that case it's still considered direct injection.

I don't know what you have against the idea of having a pre-combustion chamber. Honda themselves said they use it in their ICE. Or are you going to ignore that?

[subcritical71]

So Honda have put out information that they use a F1 legal variant of the system. What more needs to be said?

[godlameroso]

Very interesting that NOx is increased with pre-chamber volume, probably why they wrote a limit to pre-chamber volume in the regulations. You don't get NOx unless you have high combustion temps. I imagine if there is a pre-chamber the requirements for the F1 engine are vastly different with regards to pre-chamber volume, nozzle angle, number and nozzle diameter. Maybe these engines need the NOx to get the most power from the fuel?

[saviour stivala]

I haven’t claimed that rules prevent the use of pre-combustion chamber. What I claimed is the rules dictates a direct injection, and by direct injection I understand injection of fuel direct into the combustion chamber. A pre-combustion chamber is a separate chamber which leads into the combustion chamber, a chamber where combustion is started. In which engine has Honda stated they are using a pre-combustion chamber system? Could it be the 1979 civic?.

[subcritical71]

Very interesting that NOx is increased with pre-chamber volume, probably why they wrote a limit to pre-chamber volume in the regulations. You don't get NOx unless you have high combustion temps. I imagine if there is a pre-chamber the requirements for the F1 engine are vastly different with regards to pre-chamber volume, nozzle angle, number and nozzle diameter. Maybe these engines need the NOx to get the most power from the fuel?

I think the temperature is definitely helping. I come from a gas turbine background, but it sounds the same... higher combustion temperatures will always lead to higher NOx emissions, but there are catalysts that can remove this to an extent. And with the higher temperature on the T-s diagram, no matter if it’s the Otto or Brayton thermodynamic cycles, you have more available work to extract in the cycle.

[saviour stivala]

So Honda have put out information that they use a F1 legal variant of the system. What more needs to be said?

Where when and whom from Honda F1 team had said what style/type/design technology combustion chamber and or combustion process they are using, also where when and whom from the other three power unit manufacturers ever did that?.
will moderator please consider letting this question post stand.

[saviour stivala]

Very interesting that NOx is increased with pre-chamber volume, probably why they wrote a limit to pre-chamber volume in the regulations. You don't get NOx unless you have high combustion temps. I imagine if there is a pre-chamber the requirements for the F1 engine are vastly different with regards to pre-chamber volume, nozzle angle, number and nozzle diameter. Maybe these engines need the NOx to get the most power from the fuel?

can you please state the F1 rules/regulations that states a pre-chamber 'volume limit' ?

[henry]

So Honda have put out information that they use a F1 legal variant of the system. What more needs to be said?

Where when and whom from Honda F1 team had said what style/type/design technology combustion chamber and or combustion process they are using, also where when and whom from the other three power unit manufacturers ever did that?.
will moderator please consider letting this question post stand.

@saviour stivala, you have frequently been pointed to the article on page 845 of this thread that discusses the design of last year’s Honda PU. it starts with this image



Please read the headline and then go to the article and read what it means.

The regulation that says where the fuel must be injected is this:

5.10.2 There may only be one direct injector per cylinder and no injectors are permitted upstream of the intake valves or downstream of the exhaust valves. Only approved parts may be used and the list of parts approved by the FIA, and the approval procedure, may be found in the Appendix to the Technical Regulations.

So there must be one injector per cylinder and its location is fixed in the gas stream between the inlet and exhaust valves. The word direct is superfluous. You have decided the word direct means a further restriction is in place. You’ll have to live with the fact that it’s only you who thinks that.

I think this is the reg that @godlameroso referred to:

5.1.11 An insert within a PU component is a minimal, non-dismountable part whose function is solely to locally support a function of this component. The total volume of inserts within the component cannot be more than 10% of the total volume of the component.

I’m not sure that it specifically covers a pre-chamber, but there are no other regs that restrict the combustion chamber area, other than the requirement for a spark plug.

[bigblue]

A slightly related question, does anyone know the motivation is for restricting F1 engines to one injector per cylinder ? Seems to take F1 technology away from what would be implemented in road car situations as it makes things quite difficult to optimise and control ? Allowing a second injector (say) wouldn't suddenly make F1 engines much more expensive ?

[PlatinumZealot]

Very interesting that NOx is increased with pre-chamber volume, probably why they wrote a limit to pre-chamber volume in the regulations. You don't get NOx unless you have high combustion temps. I imagine if there is a pre-chamber the requirements for the F1 engine are vastly different with regards to pre-chamber volume, nozzle angle, number and nozzle diameter. Maybe these engines need the NOx to get the most power from the fuel?

At the end of 2014 Mercedes said high NOx is one of the bad sides of the F1 engines. High temps and lean combustion makes the NOx high. So avoiding that could explain why only the 2 point increase in the Hond RnD paper. But it is still mighty impressive.

[Dr. Acula]

A slightly related question, does anyone know the motivation is for restricting F1 engines to one injector per cylinder ? Seems to take F1 technology away from what would be implemented in road car situations as it makes things quite difficult to optimise and control ? Allowing a second injector (say) wouldn't suddenly make F1 engines much more expensive ?

Well, if you look at other rules, it's often the case that the FIA tries to limit the possible development. It's certainly true that a second wouldn't make the engines significanly more expensive to build, but you have to develope such a system first and that's the expensive part.
Also if one team has developed such a system and it would give them a significant advantage, the other teams also have to develope such a system to stay competitive.
But if the rules say "one injector" from the start, the playground stays fairly even. The development team never has to try out if a second injector would give them an advantage. And that in the end can save a lot of money.