How to change engine RPM levels?

I just aliased the TS2016 Sherman Hill SD70M sounds to the SD60M and I noticed that is has a very quiet idle. I figure that changing the idle RPM will fix that issue, but I'm not sure how to do that.
https://www.railworksamerica.com/forum/
https://www.railworksamerica.com/forum/viewtopic.php?f=48&t=18990
Brickrail782 wrote:I'm assuming that RWTools will work in place of Serz?