Here is a simple way to export a car from Automation to BeamNG and have it drive, sound and smoke like a diesel in the game, by doing a few basic edits to the exported files by hand:
1: Since there are no official diesel engines in Automation, we will need to create a petrol engine that mimics the characteristics of a diesel as closely as possible; this will provide the source of our horsepower output and torque curve in the game and will not be changed when we convert it into a true diesel.* Design an engine with a low power output and rev limit that is strongly optimised for low-end torque; turning the cam profile way down is a good way to achieve this. Use mechanical fuel injection instead of a carburator if you are creating the engine in the era before widespread fuel injection in petrol engines, and you may want to create the engine in an earlier era than the car in order to keep power output low without strangling it too much. In this case I’ve gone for a 2.4L OHV inline-4 which produces 68 naturally-aspirated horsepower, coming out to 28.3hp per litre. For reference, the record for horsepower per litre in production cars is 44.8hp for naturally-aspirated and 134.1hp for turbocharged diesels, but most N/A diesels are in the thirties or below and most turbodiesels in non-sports cars don’t exceed 75hp/litre.
*It is possible to edit the torque curve by hand in the exported engine, but I am not familiar with this and suggest you seek out a general modding tutorial if you want to attempt it.
2: Export the car with the fake diesel engine in it, leaving “Zip Pack Mod” unchecked.
3: Go into the “unpacked” folder of your BeamNG mods folder, find your mod, and then navigate into the [vehicle name]/vehicles/[vehicle name] directory, which should look like this:
4: Open the folder with a short sequence of random numbers and letters as a name (I have drawn a green circle around the one in my mod folder, but yours will be called something else), open the “camso_fueltank_[randomnumbers]” JBEAM file, and change the “energyType” parameter from “gasoline” to “diesel”. You can also change the name parameter to indicate that it is a diesel fuel tank, as I have done, but this will not affect gameplay.
5: Return to the previous folder, open the “eng_[randomnumbers]” folder (my particular one is circled in red two images above), and then open the “camso_engine_[randomnumbers]” JBEAM file. Look for the “requiredEnergyType” parameter (CTRL+F is the easiest way to find it) and change it from “gasoline” to “diesel”. Then look for the “soundConfigExhaust” section, find the “sampleName” parameter, and change it from the exported engine sound (which should look like a long string of numbers and letters) to one of the following default BeamNG engine sounds, depending on your engine type:
- I4D_exhaust
- I6D_exhaust (not sure which vehicles use this sound)
- I6D_2_exhaust (used in the ETK cars and Stambecco)
- I6D_semi_exhaust (for large heavy duty engines)
- V8D_exhaust
The resulting engine sound will be more diesel-like and sounds great already, but isn’t perfect. If you want to further refine the sound you can try opening up the engine JBEAM file of a default BeamNG vehicle and also copying the rest of its “soundConfigExhaust” parameters into your Automation engine.
6 (Optional): If you want to roll coal, increase the number in the “particulates” parameter under Exhaust Settings. Old engines without a catalytic converter may already be smoky enough without adjusting this setting, as it was in my case.
7: Save the text files and open BeamNG. Voila, you are now driving a diesel!
