ACS has two built-in customizable sound sets. These can be switched from the Vehicle Menu.
Vehicle sound customization is done at the top of the Root Settings script. Sounds can be called directly by UUID key between quotes like this:
string Sound_1_Horn = "f5cab6f5-f8ff-40d5-c466-467f036be078";
Or, you can place the sound file itself inside the vehicle root prim and put the sound name between the quotes.
string Sound_1_Horn = "horn";
There is no difference in performance by calling the sound by UUID as either method still calls the UUID from the server.
Alarm sounds are set at the top of the Root Menu script.
Start Sound Delay
Around line 36 in the Engine you will see the Start_Sound_Delay variable. This is the time after the start sound is triggered before the engine sound begins. So, if your start sound is lengthy, you may want to set this to 1 or 2 seconds.
float Start_Sound_Delay = 1;
Sound Packs
These additional pre-set sound packs set inside a small script can be added to your vehicle and then selected from the Sounds menu. The vehicleis designed to hold up to nine additional pre-set sound packs as well as the two sets customizable in your KCP Settings script.
You will need to set these to no transfer before they will show in your sounds menu, just add them to the vehicle and set the permissions.
_SP.ACS5 & _SP.Shvlhead are the default stock sounds that come in the scripts. If you change the sounds in the KCP Settings script but wish to include either of the original sets as an option, then add these.
_SP.Racer is a set from some sounds donated by Silverpup Howley.
_SP.KCP_Stock is the v4+ series soundset
At my shop in-world, you can buy my Ninja and Triumph 500 sound packs. My R-Engine Kit and Tets Bike kit also come with sound packs.
If you want to make your own custom sound pack to drop in your ACS install (v4+ up to currrent), contact me for the script.