Several people have asked me until now how I edit all the vehicle configs, how I create engine and gearbox files and how to setup the suspension.
This tutorial therefore will be divided into three parts where I am going to show you, how I do this magic. I will provide dummy files you can use, I will also provide the necessary programs and editor as well as excel sheets.
But there are some things you have to get yourself:
First of all: Basic mechanic understanding. How does an engine work, how does a gearbox work, how does suspension work? How does an engine generate power and torque when aspirated with a turbocharger? How when aspirated normally? What happens if you will soften the suspension on the back axle? What exactly does an anti-rollbar? eca.... All this is needed to create a good working vehicle config. I don't want to say here that I am a master in mechanic, I am still learning all of this more or less on the fly.
For the purpose of this tutorial I am going to edit the config file of the civilian Transporter.
https://dl.dropboxusercontent.com/u/84370332/Tutorial/Tutorial_files_engine.rar (checked with MS Essentials)
Physicseditor.exe - http://www.nogripracing.com/forum/showpost.php?p=377688&postcount=5
Toms Engine Shop - http://www.nogripracing.com/details.php?filenr=10153
engine_calculation - Excel sheet to convert engine diagram into code. Versions for Office 2003 and Office 2007
pictures from this tutorial
this tutorial as a *.pdf - Removed until a full version is available.
This thread is full of helping ideas and hints:
You will need Notepad++ with the SQF-plugin, found on armaholic.
Before start creating the engine files, we have do some research on the Internet. What you need is a diagram of the torque and hp output.
The real "brother" of Arma's transporter is the Iveco Daily 4x4. With a bit of google's magic, I could locate an engine diagram for the top-model engine, which is a 3.0l twin-turbocharged diesel with 174hp and 400 Nm torque. The picture I found is quite small, but it is fine as long as you can read the numbers and can see the graphs. Take a look at them and write down where the highest output of hp and Nm are and what is the red-lined RPM is. For my Iveco the values are:
130kw = 174hp from 3300-3600rpm
400Nm from 1250-3000rpm
Now that we have this diagram, we can create our custom engine file.
Open now the program "physicseditor.exe". This is the most basic tool to create an engine file. It is fairly good usable for Arma3, even though it was created for rFactor and Race07.
Click "Edit" and then "Generate new engine data".
Take a look at your notes you just made and enter the values into the box which has opened. Don't mind that in this program the max RPM you can enter is 6000. We will manually edit this later. Where asked "RPM Steps", just enter 1000. We don't need steps smaller than that. You will see later why. If you entered all values, hit OK.
The program now created a generic engine file and it might be looking like this.
Don't mind the negative compression since this value is not necessary for Arma. If this value has a high negative number, just drag-and-drop it a bit higher (closer to 0). Editing this graph won't affect the data we need.
Now, open the engine diagram again and take a closer look on the curves. Now you need basic engine understanding: Because this engine is a turbocharged diesel, the maximum torque is generated at very low rpm. To edit your engine file now, drag-and-drop the yellow torque-curve until it looks the same as the real one.
Don't mind the red power-curve. You cannot edit this due to the torque-rpm-power relation. (For more about this, read: http://en.wikipedia.org/wiki/Torque#Relationship_between_torque.2C_power.2C_and_energy - You will need this knowledge later as well)
Now go to the Edit tab again and hit "Edit Engine/Tire Parameters". A biiiiiiig window will open now, where 99% of those numbers are irrelevant. Important is only the second line where it says "Rev Limit Range".
Enter in the first field your maximum RPM, then in the second enter 0, then 1. Hit OK.
Save this file now as [nameofyourvehicle].ini and open it with Notepadd++ or any other texteditor. Also, open now the excel sheet "engine_calculation.xlsx" which I provided. Please don't mind the "Imperial Values" which is written there. It's wrong and already corrected.
What is the excel sheet about?
It takes the values of your engine file you just created and rearranges the numbers for the config. If you take a look at this, it should be pretty clear. Enter now your maximum RPM, torque and power.
The sheet will automatically calculate maxOmega, peakTorque and enginePower.
While peakTorque (in Nm) and enginePower (in kW) should be clear, maxOmega is a bit more difficult to understand.
Omega is the angular velocity, and maxOmega therefore the maximum velocity the crankshaft of the engine can reach. This value is what defines the the maxium RPM. When I first started editing configs I saw the parameter "redRpm" and was thinking that this value defines how far the engine can rev. But that's a false friend, because maxOmega "really" defines that. (Thanks here to da12thmonkey for explaining me all of this), Check the wiki page linked above for more informations.
Okay, back to the sheet. On the left-hand side there is a column named "RPM Steps". This column is rather important, because it divides your whole RPM curve into 8 steps, whereas the first step always 0 RPM is. You may ask yourself now: "Why 8 steps?!". Well, I cannot explain this to you, because this was defined by Bohemia.
Switch now back to your [nameofyourvehicle].ini. The very first lines are important, to be exactly, the ones starting with "RPMTorque". Those lines are defining the curves of torque and hp. But now, we have to trim down those lines so only 8 will be left. I hope you see now where we are going.