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Old 11th August 2010, 23:16   #1
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Default Figo -How can I Reduce load on the engine due to AC?

I've noticed that my 1.2 petrol Figo's pick-up drops substantially as soon I switch on the AC. Without the AC, however, the pickup is good (in all the gears).

On the other hand, the AC is extremely chilly. I'm never able to tolerate maximum cooling and most of the time the temperature control is 1-2 points away from the red zone. I hear that the Figo's AC compressor is larger than other cars in its segment.

Is there a way with which one can reduce the load generated by the AC? Is the load constant irrespective of the cooling temperature? I've not noticed a better pick-up with the AC set to lower cooling.
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Old 12th August 2010, 01:55   #2
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The power required to drive the AC compressor is always constant. The Figo has a comparatively big compressor and that coupled to a 1.2 mill is the cause of power loss. So if you feel that your engine is losing power, the only remedy is to switch off the AC.

I'm not sure but I think that in modern day cars, if we set the temperature to the minimum (min blower speed), the compressor does not work continuously, instead it does just whats needed. However, during the times the compressor is working you WILL feel the power loss.

One of my cousins had a Zen (prior estilo) and in that the loss of power was so obvious that sudden overtaking or steep inclines was impossible with AC on. Well, what we usually do is, just switch off the AC when engine load is more. ie, only while overtaking switch off the AC, and after the maneuver switch it back on. It makes no difference in cooling, but it really helps the engine.

- Experts please comment.

Last edited by dhanushs : 12th August 2010 at 01:56.
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Old 12th August 2010, 03:36   #3
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Close to what @dhanushs has suggested - but instead of the blower speed, set the temperature control (the dial with the blue for cooling and red for heating markings) to the minimum possible in the blue area so that it is not too uncomfortable. The blower runs out of the battery, and hence does not make any difference in the engine's load - it is the compressor runs off engine's power. And I am assuming that the car will disengage the compressor when corresponding temperature you set using the dial is reached.

I remember reading somewhere that many cars wont disengage the compressor, but mix warm air with the cold air to maintain the temperature corresponding to what you set using the dial - I hope that is not how Figo works, and the compressor actually gets disengaged Let us know.
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Old 12th August 2010, 06:57   #4
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Quote:
Originally Posted by saurabhnanda View Post
I've noticed that my 1.2 petrol Figo's pick-up drops substantially as soon I switch on the AC.

Is there a way with which one can reduce the load generated by the AC? Is the load constant irrespective of the cooling temperature? I've not noticed a better pick-up with the AC set to lower cooling.
Quote:
Originally Posted by ph03n!x View Post
And I am assuming that the car will disengage the compressor when corresponding temperature you set using the dial is reached.

I remember reading somewhere that many cars wont disengage the compressor, but mix warm air with the cold air to maintain the temperature corresponding to what you set using the dial - I hope that is not how Figo works, and the compressor actually gets disengaged Let us know.
Old "Superking" ACs that used to do duty in Premiers and Ambys had a thermostat (the outer ring would help set the temperature and the inner knob,the blower speed).This thermostat was an efficient way of controlling ac compressor cut off and consequently,load on the engine.There was no heater in this set up.

This thermostat is absent these days when all cars have HVACs.As @ph03n!x said,cold n warm air mix and this is an inefficient way of temperature control.

I guess,Saurabh,you'll have to live with the problem.Yes,one way is to keep switching the compressor off when you need the power badly and switch it on again when you're cruising.
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Old 12th August 2010, 08:15   #5
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Quote:
Originally Posted by vigsom View Post
Old "Superking" ACs that used to do duty in Premiers and Ambys had a thermostat (the outer ring would help set the temperature and the inner knob,the blower speed).This thermostat was an efficient way of controlling ac compressor cut off and consequently,load on the engine.There was no heater in this set up.

This thermostat is absent these days when all cars have HVACs.As @ph03n!x said,cold n warm air mix and this is an inefficient way of temperature control.

I guess,Saurabh,you'll have to live with the problem.Yes,one way is to keep switching the compressor off when you need the power badly and switch it on again when you're cruising.
So the only time modern AC clutches disengage the compressor is when they detect ice build up? Has anyone tried thermostat-ing a modern car's AC?

Am asking because my car gets really cold even with the temperature control turned down to 1/4th or 1/5th the way, in blower speed #1. I end up switching off the compressor manually for a few minutes, and switch it back on after a while. A thermostat that can do just that would be a great addition.
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Old 12th August 2010, 08:25   #6
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Well, I think even in figo's case the compressor never disengages, because I don't feel the pick-up varying with time with the temperate control set to a lower value.

How tough is it to simply get the compressor replaced to a smaller one? Will it help reducing the engine load?
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Old 12th August 2010, 09:37   #7
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Quote:
Originally Posted by dhanushs View Post
...So if you feel that your engine is losing power, the only remedy is to switch off the AC.

One of my cousins had a Zen (prior estilo) and in that the loss of power was so obvious that sudden overtaking or steep inclines was impossible with AC on. Well, what we usually do is, just switch off the AC when engine load is more. ie, only while overtaking switch off the AC, and after the maneuver switch it back on. It makes no difference in cooling, but it really helps the engine.
The Engine ECU takes care to cut-off the AC compressor when the Accelerator pedal is suddenly floored. In a car where the relay box is close to the driver side, one can clearly hear a distinct click sound and the engine accelerating faster. The click sound is from the relay that drives the AC compressor. One could clearly observe this on Indicas and Ford Ikons. Even in carburetted engines there use to be a limit switch at the accelerator pedal. This switch cuts off power to the AC compressor clutch as the pedal goes beyond certain position.
You dont have to manually switch off the compressor if everything else is in place.
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Old 12th August 2010, 09:39   #8
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saurabhnanda, it would void your warranty and more over it isnt worth all the trouble. I would say you follow the advice given by Phoenix.
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Old 12th August 2010, 09:57   #9
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does the new car has this power loss problem too ?? I thought that was just with Old 800 and Zen days thing. Am really surprized to see Figo having power loss problems and more surprized with 1.2 engine powers.
Btw, i assume its the petrol right ? coz, one of my friend has a figo 1.4 TDCi and i has never mentioned the power loss problem due to AC.
Any other figo user facing the same problem ??
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Old 12th August 2010, 10:16   #10
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Go for more power. Get a K&N and FFE. That should perk up your Figo.
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Old 12th August 2010, 10:43   #11
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Hey, Figo owners are now usurping the copyrighted story of Alto owners! We are veterans in handling this! What I do when I sense the engine struggling (over taking / hill climb with full load) is to quickly switch off the AC and switch it back on after completing the task. We call the AC button our "boost" button!

The Alto's set up uses the AC / Heater combo to maintain temperature, but unlike what Phoenix says, I can hear the compressor cutting in/out from time to time. This is easily noticeable from a "click" sound followed by a change in engine note. So I bet there is some system to cut out the compressor when the desired temperature is reached.

@Saurabh
I am afraid you will have to follow the Alto handbook for this! Switch off / on the AC judiciously whenever you feel the engine straining. Alternatively, shift down to a lower gear and give the stick to the engine to keep it in the power band. For example, I will shift to 4th gear @ 40 KPH and to 5th @ 50 KPH with 2 pax + no AC. For the same load with AC, I will shift at 50 and 60 KPH respectively, and will shift down to keep the power band as the situation demands. With 4 or 5 occupants in the car, this will vary further.
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Old 12th August 2010, 11:25   #12
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LIke everyone said, the only solution is to switch off the AC when you need to accelerate fast. Just dont do it too frequently. Compressors do not like quick OFF/ON and should not be restarted in under two minutes to maintain their life.

Like Gansan i have observed that the AC compressor does switch off periodically and engine power is normal till it restarts again.
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Old 12th August 2010, 11:43   #13
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Quote:
Originally Posted by dar3dev|l View Post
Any other figo user facing the same problem ??

I have 1.4 D and no issues with power loss with a/c !
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Old 12th August 2010, 11:52   #14
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But I am surprised that this problem is present even with a 1200 cc engine. In the case of Alto, this is caused by mating the larger Wagon-R AC to the 800 cc engine.

I don't think I noticed this in the Ritz even though it too has a 1200 cc engine. Nor with the Santro, that has a smaller engine.
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Old 12th August 2010, 13:01   #15
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Quote:
Originally Posted by guptavis View Post
LIke everyone said, the only solution is to switch off the AC when you need to accelerate fast. Just dont do it too frequently. Compressors do not like quick OFF/ON and should not be restarted in under two minutes to maintain their life.

Like Gansan i have observed that the AC compressor does switch off periodically and engine power is normal till it restarts again.
I guess that 2-minute (actually it is 3 minutes) rule for switching on an AC applies to home ACs and not automobile ACs. I've been switching my WagonR's AC off and on in rapid succession whenever I need more power for the past 9 years, and so far even the AC gas has not been changed. It is still working like a charm.

Quote:
Originally Posted by Gansan View Post
But I am surprised that this problem is present even with a 1200 cc engine. In the case of Alto, this is caused by mating the larger Wagon-R AC to the 800 cc engine.

I don't think I noticed this in the Ritz even though it too has a 1200 cc engine. Nor with the Santro, that has a smaller engine.
I notice it even in my WagonR and my friend who drives a petrol Swift with the old Esteem engine also notices the same in his car. It is less noticeable in the Ritz however.
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