A/C = rpms drop faster??

[coyfish]

The title says it all. Its been winter / spring here in FL so that means I can keep my windows open and turn off my AC. I have the rear engine mount so my car vibrates a bit with the A/C on (at times). Anyway its getting hotter but one thing ive noticed that with my A/C on the rpms drop a lot faster. I basically have to shift 2X as fast as I normally do for a smooth engagement. Sometimes I can't engage smoothly unless I literally shift as fast as I can. Not a big deal but im just wondering the reasoning behind this.

 

[djdanny5000]

i've noticed this aswell especially since im also in fl. i usually drive with my widows down but when its a hot day i turn on the ac and i cant shift smoothly

 

[coyfish]

Ya next time you drive watch your RPMS. They will drop super fast (compared to when AC is off).

Before I had my engine mount in I used the AC all the time. Never really noticed it but who knows.

 

[Myriad]

When the AC is off there is no load on the system... or better stated in this case, there is no added drag on the serpentine belt since the AC compressor is clutched out. When the AC is turned on you have the added load of spinning the compressor (which is compressing refrigerant vapor as it's name suggests) which adds an extra load to the entire system, thus dropping your revs faster. That's pretty standard in any compressor system.

 

[Rutedown]

With the new Cobb AP ATR, do you guys think we can have the car in 1st gear rev just a little higher to help with the vibration. Also could getting an electrical water pump help lighten the load on the serpentine belt?