Apps Folder to .ACD repacking program/app?

[Toshiba]

So i'm trying to add some adjustable gear ratios to an awesome modcar for Assetto Corsa.
I unpacked its data using content manager, and made the necessary changes, but when i tried to repack them via content manager, it said: 'cant pack data, Not allowed'
From what i read on the internet this means i dont have the privilage to repack the data (i guess because the one who made the car doesnt want it to be tampered with).
So, i find this modcar really awesome and i want to use it on tight and twisty roads as well, but it just has 1 gearset and nothing is adjustable, and the turbo lag is insane, so stock its impossible to use on those kinds of roads, im not planning to go online with it or anything, i just want to enjoy the car on more kinds of roads than just high speed stuff.
So, ive searched all over the internet to try to find a program or app with which i can repack the data folder back into an .ACD folder, if anyone knows of such an app / program, please let me know! or if you know another way thats fine too ofc : )

Thank you guys in advance and i wish you happy simracin hours!

Greetings, Toshiba

 

[aphidgod]

Before CM we used quickbms.