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is my car fu^%ed or do all off you guys notice a loss in power when you turn on the heater or the ac ??
 

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Well, it's not f**ked up. I wouldn't use the word "lose". The power might have been fluctuated but not lost. When you turn on the A/C, some power is taken to drive the A/C unit and therefore you feel a fluctuation and a delay throttle response. It's not a huge drop in power band or anything, just a slight drop in the order of 0.5 to 3 hp.

You shouldn't feel any fluctuation or loss of power when you turn on the heater cuz the heat comes directly from the already heated engine and it didn't need an added unit to manipulate the air like the a/c.
 

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G-loads said:
You shouldn't feel any fluctuation or loss of power when you turn on the heater cuz the heat comes directly from the already heated engine and it didn't need an added unit to manipulate the air like the a/c.
Not always true. Atleast not always true for my '96 G20. If you have your heat on and are using the front window defrost, your AC actually kicks on to assist with defrosting your window. The AC light does not light up, but the compressor does kick in. I will assume that all P10's are the same.
 

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The only reason you could possibly loose power by using the heater is if you have your fans on full blast. This creates more load on the alternater and makes it a bit harder to turn, but not so much that you would actually be able to notice it. The AC does suck some power from your engine when it's actually compressing. Unless you have underdrive pulleys, it won't run all the time and you'll only notice a power loss when it decides to kick on. The power loss is minimal and shouldn't affect the car's performance very much.
 

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NismoPC said:


Not always true. Atleast not always true for my '96 G20. If you have your heat on and are using the front window defrost, your AC actually kicks on to assist with defrosting your window. The AC light does not light up, but the compressor does kick in. I will assume that all P10's are the same.

That's right! I forgot about that. On my '96 it automatically turns on the AC whenever the front defroster is on. I don't think all the P10's are the same in this area, though. I believe this was added along with all of the other changes for 93.5 G20's. I don't know that it was, but I do know that the '92 I had didn't do it; so it's somewhere between then and '96.
 

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NismoPC said:


Not always true. Atleast not always true for my '96 G20. If you have your heat on and are using the front window defrost, your AC actually kicks on to assist with defrosting your window. The AC light does not light up, but the compressor does kick in. I will assume that all P10's are the same.
When you use the rear window defroster, you are drawing more current, as in voltage, from the alternator to heat the heatcoil and to drive the fan but not necessary the horsepower from the crank to drive the compressor as for the case of the AC.
 

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G-loads said:
When you use the rear window defroster, you are drawing more current, as in voltage, from the alternator to heat the heatcoil and to drive the fan but not necessary the horsepower from the crank to drive the compressor as for the case of the AC.
Not the rear defroster, the front window vents. They are set up for defrosting the front windows and the AC compressor will kick in when switched to that setting causing the engine to work more. On the 94-96, it is the button to the farthest right of the AC/heater controller.
 

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When you set the climate controls to "full defrost," it turns on the AC to dehydrate the air. This is faster than simply blowing hot air on the windshield, which is a feature, not a bug. On newer B15s, you can defeat this by setting the climate knob to "defrost/floor," which turns off the AC. I don't see why you'd want to do this, though, because if your windshield isn't defrosted yet, your engine sure as hell isn't ready for WOT blasts, either. Just keep that in mind.

I'm also pretty sure that at anything over 80% throttle, the ECU turns off the AC while you're up there. Don't quote me, though.
 

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I can check in the fsm when i get home is anyone is interested in the exact conditions that turn the a/c off, but yes, under heavy throttle your car should kick the a/c off anyways. I could feel it a lot more in my older G20 auto than i can with this 5-spd.
 

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yeah Justin if you dont' mind providing the conditions for the a/c from the FSM that would be great. it's always nice to know.
 
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