Engine.ini Turbo Configuration

Costas.H

25RPM
Jun 1, 2017
25
4
37
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

2000RPM
Premium
Mar 21, 2015
2,277
1,959
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

10RPM
Aug 6, 2014
13
11
29
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

500RPM
Premium
Nov 23, 2016
811
148
50
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

3000RPM
Premium
Dec 22, 2009
3,357
3,277
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.
 
Last edited:

Costas.H

25RPM
Jun 1, 2017
25
4
37
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

25RPM
Jun 1, 2017
25
4
37
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

3000RPM
Premium
Dec 22, 2009
3,357
3,277
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

25RPM
Jun 1, 2017
25
4
37
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.