air conditioning lag?

Skeandhu · 06-20-2000, 11:33 AM

Just wondering if anyone else notices this as well...

When driving with A/C on, there is a noticable reduction in the performance. This is to be expected, and is not a problem. However, I find that the reduction in performance is not constant. ie: when driving with the A/C on, and consistant pressure on the accelerator (to maintain constant speed) the car seems to lurch a bit, almost as if I was flicking the A/C on and off.

Some notes on the car: MY00 RS, approx 9000km (less than 6000 miles) on odo.

Is this a common thing or should I be checking with the dealer??

Input greatly appreciated.

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ttoversteer · 06-20-2000, 11:54 AM

I wouldn't worry. I have a MY99 that does the same thing. The lurching you feel is when the compressor turns itself on and off as it tries to maintain a constant temp.

Warp3 · 06-20-2000, 05:28 PM

I've noticed on my 99 2.5RS that it feels like the A/C partially disengages at 3k then moreso at 4k. I'm not sure how it "partially disengages" but I know there is a jump in power at both RPM points even under light throttle (and this doesn't seem to happen with the A/C off at either RPM point). Also I'm pretty sure the A/C disengages at full throttle regardless of RPM (I'm pretty sure all modern cars do that).

North Ursalia · 06-21-2000, 12:00 AM

Actually, the AC compressor is designed to shut off under heavy (what SOA calls "emergency acceleration", what we prefer to call "spirited driving"). Just check your users manual, it's in there. I believe it's been on every AC'd subaru since about 88 or 90.

ColinL · 06-21-2000, 12:24 AM

I specifically noted that the AC compressor didn't affect RS much when shopping a year and a half ago. Compare to the Civic Si, for instance. (yes it's displacement.)

I'm perfectly happy with the part and WOT performance of my RS running the AC. Well, not perfectly... The car needs another 100HP or so, but it performs nearly normal with the AC on.

mpaone · 06-21-2000, 12:36 AM

On a similar subject, do any of you hear a slight "squeak" when the air turns on or off? This has been happening in my 99' lately. I have an underdrive pulley... could it be that the belt needs tightening? I especially hear it when letting off the gas after full throttle (with the air on).

Matt · 06-21-2000, 12:51 AM

You'll probably need to check the belts. And yes, the A/C usually turns off around 4500rpm when accelerating hard, then re-engages at 4000rpm. Of course this is on my 1.8L so it may be different on the 2.5L.

06-20-2000, 11:33 AM	#1
Skeandhu Scooby Newbie Member#: 1056 Join Date: Mar 2000 Chapter/Region: E. Canada Location: Ottawa, ON, Canada	air conditioning lag? Just wondering if anyone else notices this as well... When driving with A/C on, there is a noticable reduction in the performance. This is to be expected, and is not a problem. However, I find that the reduction in performance is not constant. ie: when driving with the A/C on, and consistant pressure on the accelerator (to maintain constant speed) the car seems to lurch a bit, almost as if I was flicking the A/C on and off. Some notes on the car: MY00 RS, approx 9000km (less than 6000 miles) on odo. Is this a common thing or should I be checking with the dealer?? Input greatly appreciated. * Registered users of the site do not see these ads.

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06-20-2000, 11:54 AM	#2
ttoversteer Scooby Specialist Member#: 465 Join Date: Oct 1999 Chapter/Region: NESIC Location: Connecticut Vehicle: 2012 GTI Gray	I wouldn't worry. I have a MY99 that does the same thing. The lurching you feel is when the compressor turns itself on and off as it tries to maintain a constant temp.

06-20-2000, 05:28 PM	#3
Warp3 NASIOC Supporter Member#: 161 Join Date: Aug 1999 Chapter/Region: South East Location: WNC Vehicle: 06 WRX TR (SGM) 89 MR2 (Ice Blue)	I've noticed on my 99 2.5RS that it feels like the A/C partially disengages at 3k then moreso at 4k. I'm not sure how it "partially disengages" but I know there is a jump in power at both RPM points even under light throttle (and this doesn't seem to happen with the A/C off at either RPM point). Also I'm pretty sure the A/C disengages at full throttle regardless of RPM (I'm pretty sure all modern cars do that).

06-21-2000, 12:00 AM	#4
North Ursalia Miss You Mom Oct 1940 - Feb 2008 Super Moderator Member#: 809 Join Date: Jan 2000 Chapter/Region: NESIC Location: NH, Land Of Many Trees Vehicle: 2000 2.5 RS, '14 For 92 5MT SVX	Actually, the AC compressor is designed to shut off under heavy (what SOA calls "emergency acceleration", what we prefer to call "spirited driving"). Just check your users manual, it's in there. I believe it's been on every AC'd subaru since about 88 or 90.

06-21-2000, 12:24 AM	#5
ColinL Scooby Guru Member#: 114 Join Date: Jul 1999 Chapter/Region: MWSOC Location: Wichita, KS and Whoring, OT Vehicle: '03 Evo, Rice White '01 Erion CBR 929	I specifically noted that the AC compressor didn't affect RS much when shopping a year and a half ago. Compare to the Civic Si, for instance. (yes it's displacement.) I'm perfectly happy with the part and WOT performance of my RS running the AC. Well, not perfectly... The car needs another 100HP or so, but it performs nearly normal with the AC on.

06-21-2000, 12:36 AM	#6
mpaone Scooby Guru Member#: 3 Join Date: Jun 1999 Chapter/Region: South East Location: Alfretter Geeoja Vehicle: 2012 Geeteeeye and 71' VW Gulf Beetle	On a similar subject, do any of you hear a slight "squeak" when the air turns on or off? This has been happening in my 99' lately. I have an underdrive pulley... could it be that the belt needs tightening? I especially hear it when letting off the gas after full throttle (with the air on).

06-21-2000, 12:51 AM	#7
Matt Allergic to turbos Moderator Member#: 181 Join Date: Aug 1999 Chapter/Region: MAIC Location: MAIC & Southeast Vehicle: Two Subarus and a truck	You'll probably need to check the belts. And yes, the A/C usually turns off around 4500rpm when accelerating hard, then re-engages at 4000rpm. Of course this is on my 1.8L so it may be different on the 2.5L.