Methalox Fuel Ratio is wrong.

[Tweeker]

From some of the game play videos it appears that the fuel ratio for Methalox in KSP 2 is  ~4:1, visible here in the lower right hand corner. It is 5.2 CH4 to 20.8 OX. It should be ~3.6:1 or 5.65 CH4 to 20.35 OX. Please fix this.

 

[intelliCom]

3 hours ago, Tweeker said:

...the fuel ratio for Methalox in KSP 2 is  ~4:1... It should be ~3.6:1... Please fix this.

It's close enough, and better than the 11:9 mix of Oxidiser and some obscure "Liquid Fuel". There are far bigger issues that Intercept Games has to solve than what the fuel mix is.

For example:

Spoiler

• Bug fixes
  • Collisions
• Optimisation
  • Fuel crossfeed
  • Physics calculation
• (Relatively) barren parts list
  • More advanced engines still required (Metallic Hydrogen, Orion, Fusion, etc.)
  • More sources of power besides one nuclear reactor and a second RTG
  • Radiators required
• (Relatively) barren feature set
  • New game modes.
  • Heat still needs to be implemented (yes, literally, heat.)
• Changes to UI
• Tutorials
• Colonies
• Interstellar travel
  • How does approaching 0.99C work?
  • Creating missions to encourage the player to do it more
• The can of worms that is Multiplayer.
  • Reducing latency.
  • How does timewarp work?
  • How does physics calculation work? Is it peer-to-peer?
• Other solar systems, other planets and moons
• Modding

Especially that last point. Because changing a mixture ratio is such an inconsequential and minor thing that, if you want it "fixed", a mod could handle this for you without wasting developer time on the above features.

Also, fuel mixes can be different for different rocket engines. Why does it have to be 3.6:1? I know that's what SpaceX Raptor's fuel mix is, but that's the only Methalox rocket engine with a known mixture ratio (to my knowledge). I tried to check BE-4's mixture ratio, but couldn't find it. Beyond Methalox (Hydrolox and Kerolox), you have a large variety of different fuel mixes for different engines. I don't think there's any reason reason why 4:1 doesn't work for Methalox.

Edited February 23, 2023 by intelliCom

[Tweeker]

For various fuels it's more about the fuel than the engine.  There is a specific chemical ratio that each fuel type will burn best at, the  stoichiometric ratio.  Additionally rocket engines run fuel rich, meaning more the oxygen:fuel ratio is lower than stoichiometric. It's not necessary to look as specific engine to know what the fuel ratio should be.  For MethaLox the ideal ratio is slight less than 4, and the practical ratio is around 3.6 As you said Raptor uses 3.6:1, BE-4 in testing did fuel ratio sweeps from 3.5 to 3.8, So again 3.6 or 3.7 would be appropriate.

 

4:1 would be too oxygen rich and would burn up the engine. I'd be better to have it be 3.5:1 than 4:1

I'd much rather they had put effort into getting the basic stuff like this right than making sparks shoot of when you snap parts together and  maneuver nodes go "ping" when you mouse over them. And I'd rather they put effort into fixing this sort of thing now, than putting in an eyedropper so you can paint your rocket better.

 

Quote

Also, fuel mixes can be different for different rocket engines. Why does it have to be 3.6:1? I know that's what SpaceX Raptor's fuel mix is, but that's the only Methalox rocket engine with a known mixture ratio (to my knowledge). I tried to check BE-4's mixture ratio, but couldn't find it. Beyond Methalox (Hydrolox and Kerolox), you have a large variety of different fuel mixes for different engines. I don't think there's any reason reason why 4:1 doesn't work for Methalox.

 

Edited February 23, 2023 by Tweeker

[Arugela]

Why not allow the user to change the ratio and have it have realistic consequences/differences.

[HenryBlatbugIII]

7 hours ago, Tweeker said:

From some of the game play videos it appears that the fuel ratio for Methalox in KSP 2 is  ~4:1, visible here in the lower right hand corner. It is 5.2 CH4 to 20.8 OX. It should be ~3.6:1 or 5.65 CH4 to 20.35 OX. Please fix this.

What makes you so confident that the isotopic ratio on Kerbin is the same as the ratio on Earth, despite the fact that it's different by up to a factor of 100 between Earth and Luna?

Edited February 23, 2023 by HenryBlatbugIII

[Kerbart]

It's a game. I'm going to assume that to keep thins simple, the fuel ratios have been rounded to whole numbers, so 3.6 becomes 4. That way your fuel tank with 10,000 units will have 8,000 O₂ to 2,000 CH₄ instead of 2174:7826, and if you want to drain your tanks and keep half in it you'll need 4000 and 1000 instead of mental gymnastics. A lot of convenience for a small imprecision that 95% of the players won't notice.

Nate told me they rounded π as well. “By rounding it we can now calculate everything in integers, that gave us quite the performance boost”

Edited February 23, 2023 by Kerbart
Forgot to apply subscript; don't want to look too much like a troglodyte

[Vl3d]

4:1 sounds right to me for tank proportions.

[Baleine]

Oh god… Here we go again…

Please argue in terms of gameplay why it is wrong, not in terms of how it is in real life

[intelliCom]

7 hours ago, Tweeker said:

I'd much rather they had put effort into getting the basic stuff like this right than making sparks shoot of when you snap parts together and  maneuver nodes go "ping" when you mouse over them.

Willingly glossing over everything else they need to develop, I see.

I can advise three paths:

1. Make your own mod to fix the fuel ratios
2. Become popular enough to land an interview with Intercept Games, ask them why the fuel ratio is different
3. Nag someone else more popular than you to ask Intercept Games why the fuel ratio is different

Genuinely and seriously, something like fuel mix is inconsequential and a trivial thing to worry about. If you're lucky, they might just change it to 3.6:1. But this is no important feature.

Edited February 23, 2023 by intelliCom

[Tweeker]

39 minutes ago, intelliCom said:

Willingly glossing over everything else they need to develop, I see.

I can advise three paths:

1. Make your own mod to fix the fuel ratios
2. Become popular enough to land an interview with Intercept Games, ask them why the fuel ratio is different
3. Nag someone else more popular than you to ask Intercept Games why the fuel ratio is different

Genuinely and seriously, something like fuel mix is inconsequential and a trivial thing to worry about. If you're lucky, they might just change it to 3.6:1. But this is no important feature.

Not glossing over the other things, but point out that they've done something wrong that needs to be fixed.

 

[Baleine]

1 hour ago, Tweeker said:

Not glossing over the other things, but point out that they've done something wrong that needs to be fixed.

[snip]

Do you think that fixing the MethaLox burning ratio is more important than reentry effects? More important than adressing the performances issues so that more people may access the game? More important than developing the upcoming science model?

You have ideas about what need fixed, it's great. But why don't you establish a list instead of creating a post for each trivial thing you think are not right?

And just for the record, speaking of things that are wrong. The whole Kerbolar system is. Planets are way too dense for the material they are done (considering the average planet density in the universe), Kerbin's atmosphere can't be 70km high given the density and size of the planet, and I don't intend on creating a list that could go on for a while.

 

It is a game, it is not a reality simulator. So you may think that they should stick to reality for those points, and it's a valid opinion. But it's also a valid opinion to divert from it for simplicity. You can certainly understand that.

I'd really like seeing you being more supportive in taking time to make a nice list and giving arguments other than « it's not like that in our universe », because, for all we know, we probably aren't in the same universe the Kerbals are (thought of that?).

Edited February 24, 2023 by Snark
Redacted by moderator

[Tweeker]

The argument is and always has been the same, the engines they've chosen to put in the game are simulacra of real world engines, just as the planets are simulacra of real world planets.  Kerbrin is  blue and green with oceans, mountains, and other biomes similar to Earth. The Mun looks like the Moon. 

It would be no different than if Duna were green and someone said it should be red. They've done something with the Vector that is obviously not right, and they should fix it.

 

[Monger]

9 hours ago, Tweeker said:

4:1 would be too oxygen rich and would burn up the engine.

 

I think a Kerbal would risk that. 

Also, Kerbal steel seems to be a lot sturdier than earth-equivalent. Maybe for some reason they like their mix rather oxygen-rich. 

[Snark]

Some content has been redacted and/or removed. Folks, a gentle reminder to please don't make things personal.

Personal remarks are never okay. It's fine to address a person's points, but please steer clear of addressing the person themselves (such as your opinion about their behavior or attitude). It never ends well.

In other words, please address the post, not the poster.

Thank you for your understanding.

 

[Kerbart]

2 hours ago, Baleine said:

[snip]

Do you think that fixing the MethaLox burning ratio is more important than reentry effects? More important than adressing the performances issues so that more people may access the game? More important than developing the upcoming science model?

Not only that, they have to scrap all existing tanks, redesign them all for the 3.6:1 fuel ratio, retool their workshop, redo the templates and jigs, etc, so that the new tanks have the right fuel ratio? Never going to happen.