Air Cond Compressor off at WOT
 

I am curious if it disengages the AC compressor at or near WOT?

Yes.

:iagree:

thanks.... ;)

Doing harsh driving with A/C on will reduced the compressor lifespan.

how come?

Engaging the A/C clutch at higher RPMs and/or with the compressor loaded will cause more wear and tear. But rolling the windows up and down wears out the motor, cranking the engine wears out the starter, etc, so I wouldn't worry about it too much other than turning off the A/C if you plan on hitting high RPMs.

Oh.... maybe that's why my ac ain't as good ? Or maybe just need to recharge my fluids...

Hmm...

:iagree: I am sure the compressor is designed with high rpm engagement in mind.

My understanding is that most AC systems go bad due to lack of usage because the internal seals weren't properly lubricated.

I recall reading somewhere that ac compressor disengages by design at wot. The reason? Not sure, full power available for acceleration, less shock to the ac compressor/motor when it does engage.

My guess is that it's an "ordinary" clutch/compressor and that the clutch is turned off above some RPM. Too lazy to look it up in FSM. ;)

It's for performance/economy. Once engaged, the clutch and compressor can handle whatever the engine throws at it at WOT (no different, from the A/C's POV, than any other throttle position) until you reach the compressor's RPM limit. I'm assuming that modern cars turn off the clutch before the compressor is spinning too fast but see closing comment above.

My compressor should have been gone long ago if wot was hurting it, but its still quiet and efficient ;)

Plus I have a warranty that covers it for 30k more miles and 2.5 more years.

AC compressors operate off of a pressure sensor/switch. This pressure sensor/switch is set to turn off the compressor (by means of releasing the clutch) if certain parameters are not met or exceeded. This switch will shut off the compressor at too low an RPM as there's not enough pressure to properly move the fluid and lubricate the compressor, causing major wear and possible failure. Same is true at high RPMs, the fluid moves too quickly through the system at too high a pressure, also causing wear, heat and possible failure as well as lessening the effects of the cooling ability of the fluid. (fluid - gas... whatever you want to call it)

Our engines have an operating range from idle, about 700 RPM up to 7500 RPM. The compressor might only be capable of properly operating somewhere between say 500 RPM and 5500 RPM (those are just random numbers I made up). So that pressure sensor/switch would be set to disengage the clutch at those two RPM extremes to protect the compressor from self destructing so to speak.

Keep in mind, with these modern compressors and computer control, they are not effected by WOT or not, it's all basically RPM/pressure related. Old systems were more or less controlled by WOT, so when there was near zero manifold vacuum, the clutch would disengage. I'm not sure if there was any protection on the low RPM side of things.