I have been unsuccessful in preventing the initial rpm drop when switching the AC on at idle or when coming to a stop with the AC on. My idle will drop to near stalling speed ~600rpm. Here is what I have changed from stock (96940011 rom):
1. Desired idle RPM AC on set to 977 in both "Neut" rows (my AC off idle is set to 953). I left the "Drive" rows stock at 648 since I believe that "drive" applies to JDM automatic tranny Evos.
2. Timing is increased to 7 degrees at the idle rpm/load ranges.
3. My "Desired initial ISCV step position with AC on - Neutral" is increased by 20 points in the last 2 temperature ranges (77 and 82 degrees) I increased the step position from 88 and 80 to 108 and 100 respectively.

For kicks I even bumped the 82 degree initial ISCV step to 200. It had no effect. I played with the high intake temp ISCV increase but it also had no effect.

Anybody have suggestions?

 

I should also mention that my AC idle after the initial drop is steady at the set 977 rpm. I am looking to eliminate the initial drop.

 

You have cams, headwork, and hard pipes....you will need to raise the base idle RPM. Your VE is way different since you are so modded. I bet your car will idle rock solid with the IDLE RPM settings below.

Try these....
Desired Idle RPM with AC On
1141
1023
1141
1023

Desired Idle RPM-Drive
1023 for 34 degrees and higher
1203 for 20 degrees and lower

Desired Idle RPM-Neutral
1023 for 77 and 82 degrees
1203 for 50 degrees
1297 for 34 degrees
1398 for 20 degrees and below

 

Thanks for the input Appauldd. My idle is smooth like stock at its current settings except for the initial drop when AC is first turned on at idle or coming to a stop after the AC has been on. But I will try raising the desired idle a bit more. Do you suggest leaving the ISCV step settings alone? BTW altering the "drive" tables does nothing - those are for automatic transmission Evos in Japan.

 

I raised them for the just in case factor.

I am running revolver cams so my idle was horrible. I turned on the AC the car would die. With these settings I don't notice any difference in idle with the AC on.

As for the ISCV values. I never touched them. When I log the ISCV it is usually about 30 steps at idle. I used the SAS mode in EvoScan to set the BIS so the car would idle at 950. It does so, but it is really rough. Once I deactivated EvoScan SAS, the car idles great.

 

I have never touched the stepper table, and I have HKS 272's. I bumped my idle as he mentioned. But again, not due to the AC kicking on or stalling problems either. It was because of the solid front / rear mount that made my Evo idle like my old 2g on prothanes.

I wasn't having that kind of vibration inside my daily driver but the mounts were a must.
These are my settings.

DI RPM N
1296.88
1296.88
1296.88
1296.88
1203.12
1101.56
992.188
945.312

DI RPM Drive
1000
1000
1000
1000
992.188
984.375
937.5
890.625

DI RPM AC
945.312
648.438
945.312
648.438

No issues here. But I don't use my AC that often in PA.
But again... our airflow data could be different due to the fact that I am speed density. I can blow a charge pipe off and the car won't stall. I know. I've driven it 5 miles after doing so. So that could very well be the difference.