Source
r/FromTheDepths•
adestone

Turbocharger madness: bug or feature?

Hi everyone, I'm coming back to FtD after 4 years of following updates and lurking here. Really awesome to see this game and community still thriving! Amazing changes since I last played, too, and more being on the way only makes me happier.

Now, a bit of a wall of text warning.

I ran into this old issue that I still can't wrap my mind around 6 years after I started playing, you guessed which from the title. I've never understood why, in order to have any sort of competitive efficiency on your power generation from fuel - a basic and essential system - you are forced to design an ugly, asymmetrical, mind-bogglingly impractical exhaust spaghetti around turbochargers, specifically the inline ones nowadays. Should you choose not to do so, you will end up several orders of magnitude below those totally legit 50k+ ppf engines that most players seem to copy-paste into their designs (judging from the Steam Workshop) since even the most optimized "basic" setup that doesn't build around (I would say exploit) turbocharger mechanics will never get you above a few hundred ppf. How is this still a thing, after all those years of far-reaching updates that seem to have balanced most of the other systems?

From The Depths, although obviously not realistic by design, is overall pretty coherently balanced. Fuel engines however, seem like an odd one out. Maybe there should be a change in efficiency calculation, bringing in diminishing returns and an upwards limit to how much one can improve fuel efficiency by chaining exhausts, therefore bringing the optimum closer to what can realistically be achieved by the average player. Inline turbochargers should not be able to multiply efficiency many times over, it makes sense in neither gameplay nor balance.

Obviously I am not against twisting real world physics in a direction better suited to fun gameplay, FtD is an excellent and unique demonstration of why. I am just puzzled that after all this time, fuel engines are still governed by similar out-of-the-blue, counter-intuitive rules. This makes engine building tedious and not at all the fun it should be. Other FtD systems (cannons, lasers, missiles, detection, etc.) are quite the opposite: fun and captivating to build and improve upon, rather intuitive to learn, striking a great balance between customizability and complexity. I don't see why this should not apply to our good old pre-steam, pre-RTG gas guzzlers.

Thanks for reading everything! Be sure to leave your opinion and thoughts on the matter, I am really out of the FtD loop and I may be seeing a major issue where there's only a small one.

Posted Jan 29, 2020, 10:20 PM UTC

1915
Cheesecannon25•

That's one of the things they're fixing for the major resource rework

7
adestoneOP•

Oh amazing, I just had a look at the forums and found out the post from December that you are referring to.

Final power/fuel values will be ~40-60 for most compact engines, with large very efficient ones reaching ~100.

I guess that solves the issue somewhat. Many other interesting upcoming changes too, apparently among other things shield and laser power use are going down.

4
mcs175•

Sorry in advance for the wall of text, but this will take some 'splainin'.

I too have always been bothered by this too, I don't think of myself as a real world engine expert by any means, but the way you modify an engine's efficiency and power output in this game seem back asswsrds to me. Turbos and superchargers in reality are not limited to carb fed engines by any means. They also effect the whole engine not just a single cylinder. These things, as far as I know, should actually be boosting the power per cylinder, and increase fuel usage, as the point is to increase the air pressure, and hence, air mass available in the cylinder, with a corresponding increase in fuel mass to maintain combustion. IMO, a much better system would be to greatly increase power per cylinder, along with a slight decrease in efficiency, for an effect of more overall power per block, with a tradeoff in efficiency. I think that there should be a cap on the max turbos or superchargers, perhaps based on the number of cylinders, to provide some balance, and give a boost to larger engines. Could equate nicely to the real world issue of not overpressurizing the intake system. Also, a real world supercharger draws its power off of the cranckshaft of the the engine, so in game, it would provide less of a power boost effect, with similar efficiency loss. To keep it realistic and balanced, the choice to use a supercharger would be a significant cost decrease.

Similarly, fuel injectors are anything but inefficient as I understand it, as they precicely meter out the right amount of fuel. When I took a basic engine design course in college, I learned that the fuel injectors themselves will literally cost as much as the whole rest of the engine (at least in the past anyway). In my model, I would make both carbs and injectors increase cylinder power by the same amount, but injectors would have 2x to 5x the ppf, and 5x to 20x the cost per block. I also am under the impression that you cannot mix injectors and carbs as you can in this game now.

As for the real key to engine efficiency, you need to burn the fuel as slowly and completely as possible. One way to do this (that I think would translate to the game well) is much larger and longer stroke cylinders, and much lower RPM. Think like the differebce between a big diesel engine at lower rpms vs. a car engine with smaller cylinders, and higher RPM. As an example, the giant Wartszilla marine engines are sone of the most fuel efficient in the world, they can hit around %40-%60 thermal efficiency where a car engine might cap out at more like %35-%40 max. The Wartszillas usually cap out at 70 to 100 RPM, and have ~1-2m bore, ~2-4m stroke cylinders. To this end, I would love to see a small/large/huge block set for fuel engines just like steam has. I would see the tradeoff as being a slightly lower power per block, an efficiency boost with each step up, and a cost increase with each step upwards. This would also remedy the other problem I see in that the only way currently to get a lot of power is to basically spam tiny cylinders and add tons of turbos.

TL:DR

  1. turbos and superchargers should boost power per cylinder of all cylinders on the engine at once and stack
  2. A max #per engine based on cylinder count
  3. Both of the above reduce efficiency (ppf)
  4. Both could also attach to injector engines.
  5. Superchargers would give less boost, same inefficiency, for far less cost
  6. Carbs and injectors would both provide the same power boost to an attached cylinder
  7. Engines should be all carb or all injector only
  8. Injectors would give an increase in efficiency at a significant increase in cost
  9. Create small / large / huge fuel engines, where as you go uo the scale: ppb goes down slightly, ppf goes up sharply, cost (per block) goes up moderately.
5
adestoneOP•

More or less my thoughts on the matter! I was just not going to add another wall of text, haha.

Engine reactivity could also be affected (if there was such a thing) by adding rotating mass or turbocharging. Also, maybe Otto cycle (diesel) engines could be interesting, I don't know. Now we shouldn't turn FtD into Automation levels of engine design (not that I would complain, I love engines too, especially with forced induction) but seeing as some of these things are already in game for steam engines.

As for injection, while early mechanical injectors were indeed as complex as overly expensive, electronic indirect injection is actually really cheap nowadays, and generally reliable when not a bad model. Direct injection on the other hand, already on diesels for a couple decades and now reaching ignition engines, is mighty more expensive and sensitive to wear as it operates in a much hotter, harsher environment. Best ally of multifuel setups however, instead of adding a second set of injectors you just set up a 3-way valve before the high pressure pump.

2
mcs175•

That makes a lot of sense with the injectors, i had sorta forgotten about the manifold/direct inject differences. That brings up another point I thought of, I'd like to see some sort of "intake manifold" block, that would attach to the cylinders. Perhaps with an "injector" and "carburator" versions, rather than the seperate injector and carb parts. Turbos and superchargers would connect to these parts.

I've also considered 2x2 or 2x3 "vee" or even radial engine blocks that would be a combo crankshaft and cylinder piece, rather than the individual blocks system, I think it would add a nice dose of realism. I sorta started on making my own mod to implement this but stopped when I realized learning C# programming with no experience was probably more effort than I wanted lol.

2
adestoneOP•

C#, the ultimate modern barrier to modding in Unity games.

As for manifolds, I don't think it would be beneficial to add another necessary engine part. I also don't see how they would work with existing components without a deep modification of their respective uses, and our beloved devs already have truckloads of code to pump out.

1
BlackOmegaSF•

Personally, I don't mind the engines the way they are. I usually just avoid engines and treat it as a feature of the game that I don't interact with much, but others seem to enjoy.

On the Steam workshop somewhere is a huge prefab engine project. Plenty of effort and passion went into that, so clearly at least a few people are enjoying that aspect. I'd be worried that de-complicating the engines might devalue the work of those engine people. (Engineers?)

1
adestoneOP•

On the fuel engine aspect, I am totally for a deep complexity, it's just that currently the challenge is not about anything but piping. The way things are bound to change, from what I gather, engineering engines (yep that's does sound dumb) will still require lots of thought to reach the upper efficiency boundaries, it's just that you won't be able anymore to go 7000 times above the upcoming 100ppf upper limit. It'll just take you there from the 20-40ppf (quoting the dev blog again) of the least efficient engines. All in all pretty reasonable.

As someone else mentioned, I would not mind to see different size engine components, 2x2x2 and maybe even 3x3x3. And why not a set of simple engines as well to allow going ever smaller, since simple components have become so good lately.

4
adestoneOP•

Well, it is a shame as RTGs don't feel right on top of being too expensive for early builds. But alas, from the link I posted in the other comment, it's all bound to change anyway. RTGs are getting more expensive and less power dense, electric engines get set at 100% efficiency, etc. All welcome and quite logical changes.

3
Azzandra1•

Haven't turbochargers already gotten nerfed? I've only just got back into the game myself but my old blueline engine prefabs can now only reach about 400ppf, far lower than i recall them being. Or is there a new optimal engine design for efficiency?

1
adestoneOP•

They changed some things, IIRC exhausts became bidirectional (thank god) but inline turbochargers also became a thing, and along with them everything went back to 40-70k ppf possible efficiencies.

Edit: Hey, I do remember the Blueline engines! I did download them and took a good look to learn to build my own, and also just used them in a few designs. Thanks for the fine work back then!

1
Azzandra1•

Oh no, those weren't my work. Just like you, i was one of the many that grabbed them and and used them in all my personal builds. They were my go-to engine for pretty much anything that wasn't a microjet, so i have a whole bunch of prefab slices of various sizes that i can just slot into whatever I'm building.

1
adestoneOP•

Ah alright, I misunderstood you. So did I in most of my builds, tho as I tended to aim for tiny and high tech I ended up making my own. Still, looking at known good designs is a great way to learn.

2
SuwinTzi•

I just stopped caring about fuel engines when i found out a steam prop can achieve Ludicrous Speed on open water.

1
adestoneOP•

I haven't gotten around to trying them, I will probably hold off until the upcoming update since it changes many things.

2