Sorry, I don't know specifics concerning air compressors. I just use the default setting.
Since so many railroads shopped their locos it's conceivable that some SD60s had different compressors than the factory SD60 compressor.
You mentioned the SD60E prime mover RPM changing depending on operation. This makes me think that the air compressor is directly connected to the crankshaft of the prime mover. I understand this was common on earlier models of EMD, ALCo and GE locos. Other modern locos use an electrically driven compressor. e.g. the "Whoop" compressor of the modern GE
To mimic the SD60E you mention, I would use the F9 (Heavy load) and throttle combination to charge the brake line. e.g. With really high ( CV4=255, CV24=127 ) deceleration values the loco will run like the real thing.
1/ Bring your train up to speed.
2/ Drop your speed to Speed Step 1 (Speed Step 0 would be even better if it works) and press F9.
3/ Bring the throttle up to notch 3.
The decel momentum will allow you to coast a great distance while the 'compressor is charging the brake line'. Once the brake line is charged, drop the throttle setting back to Speed Step 1 and press F9 again. You once again have control over the loco speed. With some practice you should be able to minimize the time between dropping the throttle to Speed Step 1, pressing F9 (Heavy load) and throttling up to notch 3.
Using the speed tables and notch settings is feasible but will screw up compatibility with other locos in a lashup.
Let me know if you try it and if it works. Thanks!
You wrote, "
Do you know which EMD compressor on the 710 Q3 file is correct for an EMD SD60? I also wanted to rack your brain about whether or not you think it's possible to adjust the 710 file to mimic the unique notching behavior (mentioned below) of the SD60E by adjusting a combination of the speed table and notching settings?
You will notice there is low and high idle, and once above notch 3 and back to Idle the prime mover will stay up in high idle for a period of time. Once in low idle throttling up to notch 1 or notch 2 and return to idle will stay in low idle."
Good luck and have fun.