Can you disable the A/C Compressor Shutdown on Heavy Acceleration

[67guzzler]

Does anyone know if you can disable the A/C Compressor Shutdown on Heavy Acceleration? I'd really like to have it just stay on and only cycle if it's cool enough outside and and the A/C system has "caught up. " The warm spots in 95 degree days while accelerating through the gears sucks. Thanks!

 

[Tomeygun]

Does anyone know if you can disable the A/C Compressor Shutdown on Heavy Acceleration? I'd really like to have it just stay on and only cycle if it's cool enough outside and and the A/C system has "caught up. " The warm spots in 95 degree days while accelerating through the gears sucks. Thanks!

Hmmm. And I thought it was my TST box doing this...



Do you run a TST Powermaxcr?

 

[67guzzler]

Hmmm. And I thought it was my TST box doing this...



Do you run a TST Powermaxcr?

No performance enhancements yet. I'm leery about doing it before my driveline slack / G56 situation is clarified. I'm starting to come to the realization that what I'm experiencing may be normal for this transmission.



The problem is more pronounced on my 2005 G56 than it was on my 2004. 5 48RE. Seems that it relates to how hard you depress the pedal. There must be a switch or software calibration to determine this. I'd love to know if there is a setting somewhere -- maybe even in the computer. But I don't want to ruin the normal cycling of the compressor when the system is caught up. Otherwise it will freeze. Someone has to know



I just purchased a RB1 and it came today. Gonna install over the weekend. Pretty Jazzed as it's my first Nav in any car. After that, who knows. Thinking about the Bulldog Downloader but I'm not sure it's ready for the 2005's with the G56 as of yet.

 

[JLitton]

I too, have noticed this shutdown. I was going to take it in to see if there was a problem. So, from what I gather so far is that the AC Compressor shuts down during hard acceleration. For what purpose? To help the power? I could understand my little 4 cylinder work car doing this, but does this motor really need to shut down the AC for better acceleration. Seems kinda 'weeney' if you ask me.

 

[67guzzler]

I too, have noticed this shutdown. I was going to take it in to see if there was a problem. So, from what I gather so far is that the AC Compressor shuts down during hard acceleration. For what purpose? To help the power? I could understand my little 4 cylinder work car doing this, but does this motor really need to shut down the AC for better acceleration. Seems kinda 'weeney' if you ask me.

I'm with you, JLitton. I think there is enough power there and I'd rather hit the compressor button on the dash controls myself if I want more power. I don't like when things think and then make decisions for me.



I'm hoping someone knows the innards of throttle / compressor relationship and can chime in. I know it's a weird request but it would be good information to share with those in warm weather climates.

 

[PHeadings]

Run the AC control to the far left or 8 O'clock position. It doesn't shut off if your drawing the air from the inside of the cab. Recirculation mode!

 

[betterthanstock]

Interesting, in my 2003 HO 6speed, I have traveled some 20+ mile long hills with a trailer on cruise control at 70+mph and have not noticed the AC shutdown. I wonder if they changed the programming later, or if you have to be in kickdown mode before it deactivates?

 

[67guzzler]

Cali - 600 -- I run on recirc 100% of the time.



betterthanstock -- Sorry if I confused the issue -- the AC doesn't shut down -- just the compressor for a short duration. The way to tell is that if you pay attention you'll notice that the air is a little more humid and loses a cold edge for about 20 seconds after a period of fairly heavy acceleration. If it's under 90 degrees outside or the AC's been on a long time, the system will be so cool inside that it might be hard to notice. It's much more noticeable when it's really hot out.



1995 Ford Escort Wagon does this and many 4 cyl cars do this to provide more power in demanding / passing situations. I just don't need this feature with 610 ft/lbs of torque under the hood.

 

[Scooby]

I usually run my A/C with the recirculation button on and can't say that I've noticed the cycling of the compressor upon hard accelleration. I don't race the truck around much, but I will use the go pedal when I need to. I've taken my Lance (+/- 4500 lbs) up into the mountains and have not had any issues with the A/C not performing well.

 

[betterthanstock]

betterthanstock -- Sorry if I confused the issue -- the AC doesn't shut down -- just the compressor for a short duration. The way to tell is that if you pay attention you'll notice that the air is a little more humid and loses a cold edge for about 20 seconds after a period of fairly heavy acceleration. If it's under 90 degrees outside or the AC's been on a long time, the system will be so cool inside that it might be hard to notice. It's much more noticeable when it's really hot out.

I know what compressor shutdown is, but on a 20 mile long uphill in 80-90 deg weather you'd think I would notice.

My question is just how deep down is your foot before it actually cuts out? 80%, 90% 100%?

Also, it could be RPM related. If your compressor uses 1 hp at idle, then by the square law, it would use 4 hp at 1500 rpm, 9 hp at 2250, 16 hp at 3000 rpm, and 21 hp at 3500 rpm, so you see something might start to get damaged at that horse power. The fan does the same so I wonder if they need to cut it off prior to 3000 rpm too, but it's not hot enough for me to verify that where I live. Maybe you want to pay attention to that too. And they also have to cut out the alternator, but that we don't notice, since it's done electronically to the field coils.

This exponential increase of power losses also happens to the oil pump, water pump, power steering pump, fuel injection pump, and explains why your mileage gets so much worse at higher RPM. And of course the engine itself is one big air pump.