360 430 AC WHAT HAPPENS @ HIGH RPM

instantaneously?

 

I do it all the time, up to 9250 rpm and never had the issue.. Something mustn't be right..

 

The increase in RPM changes the on/off time for the compressor, it will achieve low pressure cut off very quickly then rengagement at high rpm will have significant stress for the compressor clutch.
I can understand how this level of stress could have a impact on clutch life.

 

Something is (or was) wrong. The engine ECU will open the compressor clutch when WOT is requested and also if over a certain RPM - that's standard operating strategy for any car with AC.

I'm inclined to think that the clutch on your last compressor was seized closed.

 

7500 max continuous speed is compressor rpm, not engine rpm. There is a slight reduction in between thanks to pulleys diameter.
Not normal, something was wrong with your compressor.

 

So what and when shld the off button be used?

 

It shouldn't - it's best left alone.

 

So ur saying the owners manual is incorrect?

 

No owners manual anywhere in the world will state that a driver must turn off the AC before using high RPM; the compressor clutch is ECU controlled.

 

As Mark stated this sounds like the AC compressor was on its way out anyway.

...However...

I fully agree that its dumb anyway to leave AC running at Wide open throttle, high load and high rpm. Later cars are calibrated to switch it off and on automatically.

HOT OFF THE PRESS...

So I have have done necessary work and I pleased to say can now offer to integrate this feature too into the 360 (if there is demand I will do same for other models like F430s) This new feature allow you to specify the % of torque / load at any given RPM point where you want the AC compressor to be deactivated. I will do some basic testing with given rpm points and test it fully first.

This should gain around 10hp at high rpm if you've forgotten to turn off the AC and do it automatically..

 

Way back in the early 70s before EPA emasculated ICE you could get lots of cool engines in cars. The 2nd generation Z28 came with a 350 that spun to 6500 or so which for the time was a lot. Air conditioning was not available on that engine because it couldn’t tolerate the RPM. A different era certainly but illustrates the point

 

Just to illustrate :
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On the 360, the pulleys diameter ratio is such that when the engine is at 8500 rpm, the AC compressor is at 7500 rpm.
Even without ECU control, the compressor should stay OK over the complete engine rev band.