Turbo Jbeam options

So after doing the extreme things I did for MuYe's latest video, I learned a lot about the turbo stuff. I'm probably going to want to know it in the future, so I'm writing this out, as a way to remember, and to also share the info with everyone else. So please forgive me if this is all quite centric around the way that I think.

Code:

        "turbocharger": {

this I believe, is whatever name you want to give it, but later, under "mainEngine", you have to tell it " "turbocharger":"turbocharger", ". The first "turbocharger" tells the jbeam that it has to use the powertrain lua code called "turbocharger", and the second instance of "turbocharger" is whatever you want to call it, as long as it matches this first line

Code:

   
            "bovSoundFileName":"event:>Vehicle>Forced_Induction>Turbo_01>turbo_bov",
            "hissLoopEvent":"event:>Vehicle>Forced_Induction>Turbo_07>turbo_hiss",
            "whineLoopEvent":"event:>Vehicle>Forced_Induction>Turbo_05>turbo_spin",

These are sound loops that can set, but are not the volume, or pitch (those get done later). You can listed to the other ingame sounds directly from vehicles, or in the world editor (press 'F11') window>audio>SFX Previewer, then in there, follow the addresses that are listed above to find similar ones, like "event:>Vehicle>Forced_Induction>Turbo_01>turbo_bov" or you can find the old defunct game documentation on the wayback machine for how to run "file:" instead, but I don't remember how it works

Code:

   
            "turboSizeCoef": 0.20,

I believe this is related to the pitch/volume of the waste gate (I didn't know this at the time though). Generally this can be small ~0.5, up to 1 (but it might be able to go over? I'm not sure) I've also seen a diesel with '0'. Default is 1

Code:

   
            "bovSoundVolumeCoef": 0.30,

Self explanatory, changes the the volume, based on boost pressure (I believe). Default is '0.3'

Code:

   
            "hissVolumePerPSI": 0.140,

There's a few types of sounds that layer, and it's really hard to explain audio, in text form. But I think of it as the sound of air being sucked in. Default is '0.04'

Code:

   
            "whineVolumePer10kRPM": 0.12,

This is based on the turbo's RPM, not the engines RPM, and is how much the "whine" will increase with the turbo's RPM. We'll set RPM values later. Default is '0.04'

Code:

   
            "whinePitchPer10kRPM": 0.09,

Similar to above, but changes the pitch with the turbo's RPM. Default is '0.05'

Code:

   
            "maxExhaustPower": 190000,

This is one of those "black magic" ones. My best guess is, it's how much the exhaust can power the turbo. Meaning if you have a small number, like 5000, it'll take longer for the turbo to spool, and overcome the boost threshold. Default is tricky, if you don't put it in, it'll be 1.

Code:

   
            "backPressureCoef": 0.000001,

This one I don't fully understand, but in the lua, it seems to divide the turbo's RPM, and since it's value is a small decimal point, it increases the turbo's RPM. Meaning a bigger value will spin the turbo less. Default is '0.0005'

Code:

   
            "pressureRatePSI": 30,

This has one has nothing, and I couldn't figure it out, but it seems to be used as a smoother for raw boost values. Meaning how quickly it can change boost values. Default is '30'

Code:

   
            "frictionCoef": 16,

how much the turbo wants to slow down, due to friction. Increasing the number should make boost drop off faster, when you lift off (though technically the turbo's RPM). Default is '0.01'

Code:

   
            "inertia":0.30,

How much the turbo's RPM will want to resist changes in speed. Default is '0.01'

Code:

   
            "damageThresholdTemperature": 250,

Over this value, the turbo will start taking damage, reducing its RPM.

Code:

   
            "wastegateStart":4,
            "wastegateLimit":4.5,

At what PSI the waste gate should start opening, and at what point the waste gate will be fully open, hopefully not allowing the boost to go any higher. These are fairly straight forward.

Code:

   
            "pressurePSI":[
                //turbineRPM, pressure(PSI)
                [0,       0],
                [25000,   5],
                [50000,   7],
                [100000, 9],
                [150000, 10],
                [200000, 10.5],
                [250000, 10.75],
                [300000, 10.8],
                [400000, 10.82],
                ],

The "maxExhaustPower" and "backPressureCoef" values will spin the turbo, and then the turbo's resulting RPM will correlate to PSI.

A big turbo will have less "maxExhaustPower", or more "backPressureCoef", so it'll spin less, but a larger impeller will create more pressure at the edges at all RPM ranges, if you can make it spin (just according to your values). Basically, bigger turbo should have bigger values in the second column (until some imaginary efficiency threshold is reached).

Code:

   
            "engineDef":[
                //engineRPM, efficiency, exhaustFactor
                [0,        0.0,     0.05],
                [10,      0.2,     0.10],
                [650,    0.90,   0.20],
                [1500,  0.82,   0.40],
                [2000,  0.71,   0.90],
                [2500,  0.6,     0.92],
                [3000,  0.4,     0.90],
                [3500,  0.3,     0.80],
                [4000,  0.2,     0.75],
                [5000,  0.1,     0.74],
                [6000,  0.05,   0.73],
                [7000,  0.0,     0.72],
                [8000,  0.0,     0.71],
            ]
        },

Oh yay, this was was hard to understand. First column is the engine's RPM (finally we're not talking about the turbo's RPM).

I don't understand the "efficiency" column, but bigger number means more power, and it can go way above 1, but probably shouldn't.

The "exhaustFactor" column is probably how effective the exhaust power is, for increasing the Turbo's RPM (lua seems to corroborate this). A smaller number should mean less turbo-RPM.

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if anyone has better documentation, that'd be super helpful, or better explanations too. During the creation of MuYe's mod, I basically wasn't able to find any documentation for any of this. I also hope this helps others, and myself, when I come back to this, a random amount of months, later lol