Fusion Overloader Tutorial
Introduction#
If you’re not aware, GTA IV has a way to load game files without actually replacing the game's original files.
If you create a folder called update in your GTA IV folder and add an .IMG archive called update, any modified files you put into this .IMG archive will be used over the games original files, assuming the files you’re modifying were in an .IMG archive to begin with.
So if a mod says to replace a file in an .IMG archive such as...
GTAIV\pc\models\cdimages\vehicle.img
You could instead just take the mod file and place it inside the update folder archive...
GTAIV\update\update.img
The file inside update.img will be used over the file in vehicle.img. This means you've installed a modified file without actually replacing the original game file.
What is Fusion Overloader?#
The modding community took advantage of this update folder and the result was Fusion Overloader, a type of Modloader for GTA IV that makes use of the update folder so that it can load additional .IMG archives other than update.img AS WELL as all of the other game files outside of .IMG archives.
This allows you to install mods with a simple drag and drop, without replacing game files, without needing additional tools and without needing to make backups of your game files.
Installing Fusion Overloader#
Fusion Overloader isn't really its own mod, rather it's a component of Ultimate ASI Loader, a mod which works on hundreds of games and allows modders to load their ASI plugins for any game that supports it.
While you can install Ultimate ASI Loader on its own for GTA IV, the mod actually comes packaged with Fusion Fix already, a mod you should be using if you're playing GTA IV on PC. If you haven't got Fusion Fix installed, I'd recommend following my Fixing GTA IV with 4 Mods guide to install it and some other vital mods.
For GTA IV, Ultimate ASI Loader is called dinput8.dll. For other games, it might be named differently.

Once this file is in the game folder, Fusion Overloader is active and you're ready to use the update folder to load your mods.
Installing Mods via Fusion Overloader#
Depending on the type of mod files you need to install, installation will be different. While mods built with Fusion Overloader in mind can just be installed with a simple drag and drop, many older mods provide outdated instructions and don't make use of Fusion Overloader by default.
We can do it ourselves, but files from .IMG archives have to be installed one way with Fusion Overloader and files outside of .IMG archives have to be installed another way with Fusion Overloader. So we'll cover how both are done in this guide.
Warning
Please keep in mind Fusion Overloader only works for modding original game files. Additional plugins such as ASI plugins, .dll mods and so on have to be installed normally. These type of mods don't usually replace game files, so it's not a problem anyway.
Installing Mods made for Fusion Overloader#
If you download a mod and it contains an update folder, simply copy the update folder to your game folder where GTA IV.exe is located and it'll merge with your own update folder.
That's it, a mod made for Fusion Overloader is now installed.
If the mod contains .IMG archives, you might want to make use of features such as Priorities and Episode Specific Loading. These are covered later.
Installing .IMG Mods with Fusion Overloader#
If you download a mod and it says you need to open one of the games .IMG archives to replace a file, this is how you'd install it in Fusion Overloader instead. You will need OpenIV for this.
- Open the "update" folder and create a new folder. Name the new folder after the mod you're installing, e.g. if you're installing a mod called HQ Vehicles, name the folder
HQ Vehicles. - Launch OpenIV, enable "Edit mode" in the top right, go to the
HQ Vehiclesfolder you created in theupdatefolder, right click anywhere in the folder and create a new .IMG archive, name the archive after the mod. - Using OpenIV, open the archive and place the files from the mod into the .IMG archive you just created.
That's it, the mod files inside GTAIV\update\HQ Vehicles\HQ Vehicles.img will now be used over the original game files.
Priorities#
If you have two .IMG mods which replace the same files, you can choose which one you want to be used over the other using the priority system.
Fusion Overloader will load .IMG archives based on the alphabetical order of the folders they're in, so you should use numbers at the start of the folder names to prioritize mods.
For example...
You have two mods which have modded files that change the Infernus, the mods are in folders called HQ Vehicles and TJGMs Enhanced Infernus.
Both folders have an .IMG archive in them which contain the Infernus files infernus.wft (model) and infernus.wtd (texture).
You want to keep HQ Vehicles because you like the other vehicle mods it contains, but you would like to use the Infernus files from TJGMs Enhanced Infernus instead.
If we don't add a number at the beginning of the folder names and just leave them like this...
GTAIV\update\HQ Vehicles\HQ Vehicles.img
GTAIV\update\TJGMs Enhanced Infernus\TJGMs Enhanced Infernus.img
Then the Infernus files within HQ Vehicles.img will be used instead of the Infernus files within TJGMs Enhanced Infernus.img. Because the folder HQ Vehicles is first alphabetically.
But if you use numbers, you can prioritize the folders like this...
GTAIV\update\1. TJGMs Enhanced Infernus\TJGMs Enhanced Infernus.img
GTAIV\update\2. HQ Vehicles\HQ Vehicles.img
Because the folders are now numbered, 1. TJGMs Enhanced Infernus is now prioritized over 2. HQ Vehicles as it comes first alphabetically. So the Infernus files in TJGMs Enhanced Infernus.img will be used over the Infernus files in HQ Vehicles.img.
Episode Specific Loading#
If you only want an .IMG archive to load depending on whether you're playing the base game or one of the episodes, you can do that with Fusion Overloader too.
For example...
If you only want HQ Vehicles to be enabled when playing the main GTA IV game, you can place the .IMG archive into a folder called IV and it'll only load when playing the base game.
GTAIV\update\HQ Vehicles\IV\HQ Vehicles.img
If you only want it enabled during The Ballad of Gay Tony...
GTAIV\update\HQ Vehicles\TBOGT\HQ Vehicles.img
And if you only want it enabled during The Lost and Damned...
GTAIV\update\HQ Vehicles\TLAD\HQ Vehicles.img
Installing non-IMG Mods with Fusion Overloader#
If you download a mod and it says you need to replace a game file that's NOT in an .IMG archive, it's done a bit differently. Game files not within .IMG archives need to their location mirrored in the update folder.
Here's two examples...
-
You download a mod which changes
timecyc.dat. The mod instructions tells you to replace the original file located atGTAIV\pc\data\timecyc.dat.To install the modded file using Fusion Overloader, just mirror the location in the update folder like so
GTAIV\update\pc\data\timecyc.dat.The modded
timecyc.datmirrored in theupdatefolder will now be used instead of the originaltimecyc.dat. -
You download a mod which changes
WeaponInfo.xml. The mod instructions tells you to replace the original file located atGTAIV\common\data\WeaponInfo.xml.To install the modded file using Fusion Overloader, just mirror the location in the update folder like so
GTAIV\common\data\WeaponInfo.xml.The modded
WeaponInfo.xmlmirrored in theupdatefolder will now be used instead of the originalWeaponInfo.xml.
Installing .asi Scripts/Plugins#
TODO
Profiles#
Fusion Overloader also allows you to create profiles that contain whatever mods you want. So when you launch the game, you can choose exactly what profile and mods you want to load.
Enabling Profile Functionality#
To use this functionality, create a file called dinput8.ini (make sure file extensions are enabled in your file explorer), you can then open this file with any text editor including Notepad on Windows.
Inside this .ini file, add the following to the .ini file and then save it.
[FileLoader]
OverloadFromFolder=update
This specifies that the folder Fusion Overloader is loading your files from is called update. While you can change the name from update to whatever you want, I'd recommend leaving it as update as it's the default name and many mods made with Fusion Overloader in mind will assume that's going to be the name of the folder.
Creating an Addtional Profile#
With profile functionality enabled, you can now create additional profiles that can load mods from folders other than the update folder.
Here's an example...
You have two mods, one is TJGM's HQ Vehicle Pack and another is Ash_735's HQ Vehicle Pack. If you want a profile you can use to load only one or the other, this is how you'd do it.
- Install
TJGM's HQ Vehicle Packas you normally would inside theupdatefolder.
Then to create another profile which only loads Ash_735's HQ Vehicle Pack, you do the following...
-
Create a folder called
ashvehicles(can be named whatever you want). This folder will act like anotherupdatefolder and mods should be installed here the same way they're installed in theupdatefolder (see the rest of this guide for information on how to install different file types) -
Install
Ash_735's HQ Vehicle Packinto theashvehiclesfolder. -
Open
dinput8.dlland afterOverloadFromFolder=updateadd| ashvehicles. Your .ini file should now look like this.[FileLoader] OverloadFromFolder=update | ashvehiclesThis now means that Fusion Overloader has the option to either load files from the
updatefolder (which contains the files forTJGM's HQ Vehicle Pack) or theashvehiclesfolder (which contains the files forAsh_735's HQ Vehicle Pack). -
Launch the game, you should now see a dialogue box which asks you which folder you want Fusion Overloader to use. Option 1 will use the mods in the
updatefolder, option 2 will use the mods in theashvehiclesfolder.TODO
You don't necessarily need to install TJGM's HQ Vehicle Pack into the update folder. You can add multiple folders to Fusion Overloader, put your mods in them and then just use them without using the update folder.
Example...
[FileLoader]
OverloadFromFolder=update | ashvehicles | tjgmvehicles
And when we launch the game, we can choose to use the mods in either...
- The
updatefolder - The
ashvehiclesfolder - The
tjgmvehiclesfolder
TODO
Loading Multiple Profiles#
As well as creating additional profiles that can load their own set of mods, you can also load multiple profiles together and mix and match profiles in different scenarios.
Here's an example...
You have all your essential mods installed in the update folder (Fusion Fix, Console Visuals, Various Fixes, etc...), you want to install some weapon mods but you want them to be kept seperate and you still want them to load alongside your essential mods in the update folder.
-
Create a folder called
weaponmods(can be named whatever you want) and install your weapon mods there. This folder will act like anotherupdatefolder and mods should be installed here the same way they're installed in theupdatefolder (see the rest of this guide for information on how to install different file types) -
Open
dinput8.iniand afterOverloadFromFolder=updateadd< weaponmods. Your .ini file should now look like this.[FileLoader] OverloadFromFolder=update < weaponmods -
Launch the game, you should now see a dialogue box which asks you if you want to load the
updatefolder on its own or theupdatefolder + theweaponmodsfolder.TODO
You can do this for multiple folders, so you could have something like this...
[FileLoader]
OverloadFromFolder=update < weaponmods < vehiclemods
And when we launch the game, we can choose to use the mods in either...
- The
updatefolder - The
weaponmodsfolder + theupdatefolder - The
vehiclemodsfolder + theweaponmodsfolder + theupdatefolder
TODO
You can mix this up with using using | to start a new chain.
[FileLoader]
OverloadFromFolder=update < weaponmods | vehiclemods
With our .ini like this, we can choose to use the mods in either...
- The
updatefolder - The
weaponmodsfolder + theupdatefolder - The
vehiclemodsfolder
TODO
Or we could do it like this...
[FileLoader]
OverloadFromFolder=update < weaponmods | update < vehiclemods
And then we can choose to use the mods in either...
- The
updatefolder - The
weaponmodsfolder + theupdatefolder - The
vehiclemodsfolder + theupdatefolder
TODO
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