[5/5/2022|1.43-1.44]
This mod is Cummins ISX Signature with straight piped sound for SCS and modded trucks

Version 1.0 Feature:
-Cummins ISX Signature 520-620HP with straight piped sound
-Custom sound attenuation for realistic sound fade off with distortion effects
-Custom exhaust distortion for realistic exhaust tone and works along with custom attenuation
-Custom sound orientation for realistic sounds from different angles
-Included idle jake brake system
-Included Improved Customizable Additional Supported Trucks (CAST) in the mod
If you don't know what CAST is :
https://steamcommunity.com/workshop/filedetails/discussion/665335536/3156453942274154402/

Quick tutorial on how to use CAST
1. Goto def/vehicle/truck/
2. Rename one of zcustom_xx into truck def name you want
and you should good to go

How to use idle jake brake:
1. hold light horn button (J button) then release
2. tap light horn button once again, and idle jake brake should be engaged
3. Repeat the same process to turn off 

Note: idle jake brake system will not work with some kind of interior sound mods

Credits:
Slav Jerry - sound samples, mixing and modding
SCS Software - one sound sample