Engine.ini Turbo Configuration

[Costas.H]

Hello guys.

I want to ask how you can properly configure the turbo parameters in engine.ini for some close to reality results. Let's say, a turbo that runs at 19.5psi at 3500rpm and tapers to 16psi by 6500rpm, how you can configure the engine.ini to mach this? How i know the wastegate, reference RPM and gamma really is?

 

[AccAkut]

Hello guys.

I want to ask how you can properly configure the turbo parameters in engine.ini for some close to reality results. Let's say, a turbo that runs at 19.5psi at 3500rpm and tapers to 16psi by 6500rpm, how you can configure the engine.ini to mach this? How i know the wastegate, reference RPM and gamma really is?

you can set up a second "negative" turbo, just using negative values for boost. Some mods already use this technique and iirc even the Kunos 962Cs, or one of the two, do.

 

[PJohann]

Hello guys.

I want to ask how you can properly configure the turbo parameters in engine.ini for some close to reality results. Let's say, a turbo that runs at 19.5psi at 3500rpm and tapers to 16psi by 6500rpm, how you can configure the engine.ini to mach this? How i know the wastegate, reference RPM and gamma really is?

You can do this by setting up additional controller for turbo. Set your wanted peak boost and other parameters in engine.ini and then create new .ini for detailed boost curve

Example: filename "ctrl_turbo0.ini" if you have more than one turbo in engine.ini then you will need a separate ctrl file for each. Like ctrl_turbo1.ini ctrl_turbo2.ini and so on.

[CONTROLLER_0]
INPUT=RPMS
COMBINATOR=ADD
LUT=(|0=1,34|3500=1,34|6500=1,10|)
FILTER=0.99
UP_LIMIT=10000
DOWN_LIMIT=0.0

LUT - is where you do your magic, you can add as many sections as you want there in |RPM=boost| format.

 

[dud]

Is there ever a reason to allow higher boost than the wastegate allows?

In a real car, is pressure peaking to above wastegate threshold and then tapering off?

 

[Stereo]

In a real car the wastegate is hot side and doesn't manage boost levels directly, just limits how much pressure is on the exhaust turbine. It's the efficiency of the turbo decreasing as airflow increases that makes boost taper off.

In AC I don't think there's any particular reason to have wastegate and max boost be different. You'll just have it stop building boost at whatever point it gets to the pressure limit. It's mostly just there for cockpit-controlled boost.

 

[Costas.H]

In a real car the wastegate is hot side and doesn't manage boost levels directly, just limits how much pressure is on the exhaust turbine. It's the efficiency of the turbo decreasing as airflow increases that makes boost taper off.

In AC I don't think there's any particular reason to have wastegate and max boost be different. You'll just have it stop building boost at whatever point it gets to the pressure limit. It's mostly just there for cockpit-controlled boost.

So....
[TURBO_0]
LAG_DN=0.998
LAG_UP=0.996
MAX_BOOST=1.344
WASTEGATE=1.3
DISPLAY_MAX_BOOST=1.3
REFERENCE_RPM=3500
GAMMA=2
COCKPIT_ADJUSTABLE=0
19.5psi=1.344bar

 

[Costas.H]

You can do this by setting up additional controller for turbo. Set your wanted peak boost and other parameters in engine.ini and then create new .ini for detailed boost curve

Example: filename "ctrl_turbo0.ini" if you have more than one turbo in engine.ini then you will need a separate ctrl file for each. Like ctrl_turbo1.ini ctrl_turbo2.ini and so on.

[CONTROLLER_0]
INPUT=RPMS
COMBINATOR=ADD
LUT=(|0=1,34|3500=1,34|6500=1,10|)
FILTER=0.99
UP_LIMIT=10000
DOWN_LIMIT=0.0

LUT - is where you do your magic, you can add as many sections as you want there in |RPM=boost| format.

Interesting technique, but i cannot understand what these parameters in [CONTROLLER_0] represent. In LUT we have car's RPM's=what?

 

[Stereo]

it's RPM|Wastegate

 

[Costas.H]

it's RPM|Wastegate

Hey awesome! Now it's start to make sence to me. What about COBINATOR, FILTER, UP_LIMIT and DOWN LIMIT?

 

[Stereo]

Combinator is how it applies to the previous value of the parameter (in this case there isn't one since it's the first controller), eg. you could have one based on RPM multiplied by one based on gears. ADD and MULT are the two options.

Filter is how quickly the value changes, works the same way as lag_up/dn. Basically the new number each physics step is this times the old value plus (1-this) times the lut value

up and down limits just cap things off, if you have a series of adds and want the max at the end to be 2 you'd set up_limit=2.

 

[Costas.H]

Nice. This clear things. Max and min values i can use?

 

[Terry Rock]

Great topic guys.
Turbos are fun to play with and tune for.

 

[Costas.H]

Yes it is. I found some exceptable (not entire piece of crap physics) car mods sometimes, but with entire wrong power.lut, drivetrain, turbo settings. So play with those settings for more realistic/convincing results.

 

[T0rqu3_]

Can you use any of these files to make the turbo button overridable? So it develops boost only when you keep the assigned button pressed?

 

[sab00000001]

Slightly off topic, but related: Is there a [TurboHint_] value that can be applied in the track's ai_help.ini? I see the ai seems to be adjusting the turbo on some cars... where is that control coming from?

 

[Horsewood 74]

Did you find a solution to this, im working on a mod car, and i have turbos working, but the ai dont use them, its an adjustable turbo, ive obviously missed a setting somewhere.

 

[Jens Roos]

In a real car the wastegate is hot side and doesn't manage boost levels directly, just limits how much pressure is on the exhaust turbine. It's the efficiency of the turbo decreasing as airflow increases that makes boost taper off.

Sorry for the thread lift here but that's not entirely correct statement, in real-life the wastegate is controlling the pressure in the intake manifold by opening/closing the wastegate (and passing exhaust gas directly into the exhaust system) and by doing that regulating the speed of the turbine. As the hot & cold side of the turbo is on the same shaft, that will control the pressure created in the manifold.

If you didn't control the turbine speed with the wastegate, you would probably blow up your engine. Then there lots of other parameters to consider when controlling turbo pressure as well.


But if that have any effect and how in detail AC is simulating Turbo I have no clue.