Welcome to the North American Subaru Impreza Owners Club Thursday November 27, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC General > General Community

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 07-24-2006, 02:23 AM   #51
nhluhr
John Wayne Toilet Paper
Moderator
 
Member#: 7327
Join Date: Jun 2001
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
2008 Mazdaspeed3
2006 Wrangler Sport

Default

Quote:
Originally Posted by CynicX
The Maryland State Police posted a report that the highway pratrol man get better MPG using the A/C vs having the windows down (anything to save a dime I guess).
I would hazard a guess that those SP's using the AC instead of windows are also going to have less hearing loss and also be more comfortable/presentable from not sweating on the hotter days.
* Registered users of the site do not see these ads.
nhluhr is offline   Reply With Quote
Old 07-24-2006, 12:25 PM   #52
AbsolutShyam
Scooby Newbie
 
Member#: 116261
Join Date: May 2006
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
2008 Legacy GT
Dark Grey

Default

Quote:
Originally Posted by ElementalFiend
I'm driving an '06 2.5i and there isn't much of a difference.
I have a 2.5i too and I dont notice much of a difference. My friend's Mini Cooper S has a huge difference starting from stop with AC or without. Could NA vs FI make a difference?
AbsolutShyam is offline   Reply With Quote
Old 07-24-2006, 12:52 PM   #53
licwyd7755
Scooby Newbie
 
Member#: 63635
Join Date: Jun 2004
Location: West Chester
Vehicle:
04 Impreza
There is no T in Impreza!

Default

Quote:
Originally Posted by REX8
its a huge difference...actually have to shift faster the revs fall off so quick....

+1.......


.......I can't stand driving with my AC on. Tust me, with temps hitting tripple digits on a daily basis, and humidity levels way over eleventy billion %, I would be using it if there was no difference.

Last edited by licwyd7755; 07-24-2006 at 12:58 PM.
licwyd7755 is offline   Reply With Quote
Old 07-24-2006, 01:10 PM   #54
theicewall
Scooby Specialist
 
Member#: 70532
Join Date: Sep 2004
Vehicle:
2004 WRX
WRB

Default

Quote:
Originally Posted by Subie Gal
huh?

under WOT the AC shuts off....

i have AC in my race car, and run with it on each and every race.

*shrug*

to each their own i guess but i have not noticed any power loss.

Jamie
It does shut off at WOT, but evertime I change gears it clicks back on and the revs drop too quickly and it makes the revs too low for the next gear unless I really force the shifter into the gate. What about if you are at part throttle in a race, it definitely makes the throttle more dull and not as responsive? I guuess you've just gotten used to it, or it doesn't make as big a difference on the dirt.
theicewall is offline   Reply With Quote
Old 07-24-2006, 02:30 PM   #55
mastamind
Scooby Newbie
 
Member#: 110159
Join Date: Mar 2006
Chapter/Region: MWSOC
Default

Quote:
Originally Posted by 8Complex
Having AC on in my car makes it go faster. True story.
Mine too! It's still not as fast as an SRT-4 with the A/C on......
mastamind is offline   Reply With Quote
Old 07-24-2006, 02:44 PM   #56
Howl
Scooby Specialist
 
Member#: 57830
Join Date: Mar 2004
Location: Tory Nation :I
Default

Quote:
Originally Posted by aerostar
Actually they did a test on Mythbusters, one of my favorite shows. What was interesting was that at 50 MPH the truck with the windows down went around 20-25 more miles than the truck that had the windows up with the A/C on. oO
That's interesting. I'm sure every make and model has a different break even point (if there is a break even point). A more aerodynamic vehicle will likely have a lower break even point than a less aerodynamic one, and a vehicle with a larger engine will expend a much lower percentage of its power on AC than a smaller car, thus the impact will be a lot less obvious. A Pruis, for example, is probably much more effiecent with AC on than with the windows down at 50mph. I don't know why they would have choosen the worst vehicle to run their test on rather than the best, or at least a more typical, vehicle (unless of course they set it up so they could "bust" the myth).
Howl is offline   Reply With Quote
Old 07-24-2006, 05:09 PM   #57
z&cobb
Scooby Specialist
 
Member#: 12344
Join Date: Nov 2001
Chapter/Region: MAIC
Location: Mountains of Maryland
Vehicle:
2002 2JC
blue

Default

The second radiator fan goes on with the AC switch. Hence, the mod to keep the AC from going on, yet turn on the second fan, can increase performance under some circumstances. This was described on Nasioc a long time ago.
z&cobb is offline   Reply With Quote
Old 07-24-2006, 05:13 PM   #58
wonkothesane26
Scooby Newbie
 
Member#: 33362
Join Date: Feb 2003
Chapter/Region: Tri-State
Location: Now with 100% more mods!
Vehicle:
2004 WRX Sedan
Pockmarked/dented silver.

Default

On a positive note, once I installed my stealthback and picked up 15 or so hp, the power suck from a/c isn't noticable. I still hardly ever use it, but it helps.
wonkothesane26 is offline   Reply With Quote
Old 07-24-2006, 05:20 PM   #59
CatfaceType-R
Scooby Guru
 
Member#: 81102
Join Date: Feb 2005
Chapter/Region: MWSOC
Location: I sell platinum cat jewelry.co
Default

Quote:
Originally Posted by 8Complex
Having AC on in my car makes it go faster. True story.

yah man, i pump ac into my intercool4r and through my vents, real fast if you ask me..especially at wot cuz it teh shuts down my interior vents and just blows cold air at my intercoolr, god i love this ^ mount setup
CatfaceType-R is offline   Reply With Quote
Old 07-24-2006, 05:36 PM   #60
Chuck H
Scooby Specialist
 
Member#: 20442
Join Date: Jun 2002
Chapter/Region: NESIC
Location: Chelmsford, MA
Vehicle:
KTR tuned 2003 WRX
VF34 equipped, 270 whp

Default

It's a very noticeable difference between AC on and off at part throttle in a 2.0L WRX. I turn mine off momentarily when getting ready to start from lights and stop signs because it bogs the motor down so much that it's hard to start smoothly. And trying to get the revs up off idle for hill starting with the A/C on takes a ton more throttle than with the AC off.

It may switch off at full throttle, but it's definitely like dragging around a boat anchor in normal driving with small throttle openings.

Last edited by Chuck H; 07-24-2006 at 05:42 PM.
Chuck H is offline   Reply With Quote
Old 07-24-2006, 05:50 PM   #61
grzydj
Scooby Specialist
 
Member#: 84984
Join Date: Apr 2005
Chapter/Region: MWSOC
Location: Sioux Falls, South Dakota
Vehicle:
2006 Impreza 2.5i 5D
'04 Toyota Tacoma TRD

Default

Any small displacement engine without a lot of low end torque is going to be affected by the presence of an A/C compressor turbo or not. I find that double clutching helps a bit to get rid of some of the drivetrain slack induced by the laggy engine, but it's rare that I use A/C as the heat doesn't bother me.
grzydj is offline   Reply With Quote
Old 07-24-2006, 06:31 PM   #62
IronMonkeyL255
Scooby Specialist
 
Member#: 38120
Join Date: Jun 2003
Chapter/Region: South East
Location: Greenville, SC
Vehicle:
1991 Rio Red
Legacy Turbo

Default

Quote:
Originally Posted by Subie Gal
subaru's AC system shut off under WOT ... period.

so if you need power, you get it....

Jamie

Out of curiosity, when did they start this?

I thought I noticed it in my '91 LT, but that may just be something else. It didn't seem to shut off in my '94 wagon, but it was so slow that I probably just didn't notice.

I knew WRXes did, but I just didn't know what all else they did it in.....
IronMonkeyL255 is offline   Reply With Quote
Old 07-24-2006, 06:40 PM   #63
'05STi
Scooby Specialist
 
Member#: 87439
Join Date: May 2005
Chapter/Region: SCIC
Location: Sherman Oaks
Vehicle:
2009 S2000
'09s2KnEGAtiVeSHifTiNg!

Default

It is harder to notice the difference when driving an auto with the air on. With the air on, driving stick, it is more easily noticed, you have to work the clutch/gas a bit differently.
'05STi is offline   Reply With Quote
Old 07-24-2006, 06:44 PM   #64
shemoves
Scooby Guru
 
Member#: 80663
Join Date: Jan 2005
Chapter/Region: SWIC
Location: Glendale, AZ
Vehicle:
1997 Outback

Default

I try to go w/o using AC whenver possible. It is more strain on everything from the engine to the cooling system. Although it is not too bad on our cars, it can use up to a third of a vehicle's gas just to run the AC. Regrding auto-shutoff and WOT, it is a cool feature, but it still sucks when trying to just get on it a little. If I am getting on the freeway I just turn it to 'vent' temporarily or push the AC button to turn it off during the WOTness. It's not the fans that are teh suck, it is running the AC compressor.

It is a good idea; however, to run it for a few minutes at least once a month to maintiain the seals/lubricate stuff.

So ya'll know, I've found that at speeds above 55ish, I get the best best balance of circulation and tolerable noise from rolling down just the 2 passenger side windows about 3-4 inches.
shemoves is offline   Reply With Quote
Old 07-24-2006, 06:48 PM   #65
shemoves
Scooby Guru
 
Member#: 80663
Join Date: Jan 2005
Chapter/Region: SWIC
Location: Glendale, AZ
Vehicle:
1997 Outback

Default

Quote:
Originally Posted by nhluhr
I would hazard a guess that those SP's using the AC instead of windows are also going to have less hearing loss and also be more comfortable/presentable from not sweating on the hotter days.
MythBusters did the same test with an SUV @ about 50-55 mph and the windows car won. I guess it would depend on the speed of the vehicle and how much it relies on aero for it fuel economy. An SUV is not taking nearly as much of a aerodynamic hit as say a modern Legacy with the windows down. Also, the effects of drag increase significantly as speed increases.

So, if yur just puttin' around, go windows. But if you were cruising on the freeway and basically keeping a constant speed, use AC.
shemoves is offline   Reply With Quote
Old 07-24-2006, 06:54 PM   #66
nhluhr
John Wayne Toilet Paper
Moderator
 
Member#: 7327
Join Date: Jun 2001
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
2008 Mazdaspeed3
2006 Wrangler Sport

Default

Quote:
Originally Posted by shemoves
Also, the effects of drag increase significantly as speed increases.
I have previously calculated the amount of power consumed solely by wind drag on the 2004 STi. It basically works out that any speed above about 40mph, it is better to have the windows rolled up.
nhluhr is offline   Reply With Quote
Old 07-24-2006, 07:17 PM   #67
saab-on-the-cobb
Scooby Specialist
 
Member#: 116330
Join Date: May 2006
Chapter/Region: South East
Location: 132&Bush I got em at gunpoint
Vehicle:
2005 Ram SRT-10
Sex Silver

Default Okay...

Quote:
Originally Posted by Subie Gal
we're not talking about GAS MILEAGE

we're talking about POWER
and...

subaru's AC system shut off under WOT ... period.

so if you need power, you get it....


this has been covered a 100gazillion times...

Jamie
Uh, the car gets better mileage w/ ac OFF, because the AC isn't using any POWER when it's off.

EVERY FEATURE, from hazards to headlights, requires POWER to use. Period. You can't make freezing cold air without P O W E R.


I am not denying the car cuts ac load at WOT. It does.


WHY do you think that's so? BECAUSE THERE IS A POWER LOSS. (Duh.)

If there were NO LOSS, there would be NO NEED to cut the AC at WOT.

Ponder that for a second.

ALSO: You are not running at WOT every time you hit the gas (well, maybe you are, but not most folks). Off the line, do you run at WOT? I have yet to meet someone who launches at WOT very well.

Here's another test: Go to the drag strip and do four runs: Two w/ ac, and two without. Guess what? You'll run much faster without AC. IN ANY CAR.

FINALLY: Datalog a stock REX in 90+ degree weather with A) AC off and B) AC on under heavy load. Guess which exhibits more detonation? AC on.

It's funny to see someone as knowledgeable as yourself talk down to others when you have no apparent knowledge of the physics of how a vehicle's AC works either. Just because a car cuts AC at WOT does NOT mean you should push its limits with the AC on.

As I said before, IT CUTS AC FOR A REASON: To prevent the H U G E current demand of your AC system.


Every action has an equal and opposite reaction. Compressing and cooling warm air requires POWER. Period. Try to run your ac with no alternator. It won't work too well. It's why they run those red and black wires to all of the gizmos in your Subie...they require power.

Saab-on-the-Cobb
saab-on-the-cobb is offline   Reply With Quote
Old 07-25-2006, 12:16 AM   #68
Shoemaker2
Scooby Newbie
 
Member#: 119943
Join Date: Jul 2006
Chapter/Region: BAIC
Location: Philly and Santa Cruz
Vehicle:
03 WRX
Silver

Default

I don't know. In my 94 4runner turning off the AC is like turning on a turbo. I hardly ever use it.
Shoemaker2 is offline   Reply With Quote
Old 07-25-2006, 01:04 AM   #69
PRS82F
Scooby Newbie
 
Member#: 116385
Join Date: May 2006
Chapter/Region: SCIC
Location: Irvine, CA.
Vehicle:
2009 STi
Red

Default

All you people need to get a life. 3 pages on power loss w/ the AC on.
Jesus Christ you should all be driving 20 year old Hyundais.
PRS82F is offline   Reply With Quote
Old 07-25-2006, 09:49 AM   #70
grzydj
Scooby Specialist
 
Member#: 84984
Join Date: Apr 2005
Chapter/Region: MWSOC
Location: Sioux Falls, South Dakota
Vehicle:
2006 Impreza 2.5i 5D
'04 Toyota Tacoma TRD

Default

Quote:
Originally Posted by PRS82F
All you people need to get a life. 3 pages on power loss w/ the AC on.
Jesus Christ you should all be driving 20 year old Hyundais.
There is no such thing as a 20 year old Hyundai.
grzydj is offline   Reply With Quote
Old 07-25-2006, 10:01 AM   #71
REX8
*** Banned ***
 
Member#: 24038
Join Date: Sep 2002
Chapter/Region: South East
Location: Godspeed Cale...
Default

Quote:
Originally Posted by PRS82F
All you people need to get a life. 3 pages on power loss w/ the AC on.
Jesus Christ you should all be driving 20 year old Hyundais.
You were darn close to making it 4 pages...
REX8 is offline   Reply With Quote
Old 07-25-2006, 10:08 AM   #72
enozto
Scooby Newbie
 
Member#: 32122
Join Date: Jan 2003
Location: nj
Vehicle:
09 Kuota

Default

i dont see any lose of power in my car.
enozto is offline   Reply With Quote
Old 07-25-2006, 11:07 AM   #73
nab911
Scooby Newbie
 
Member#: 119866
Join Date: Jul 2006
Chapter/Region: South East
Location: Atlanta, Ga
Default

Its not a signifigant loss in power, but enough to make honda drivers notice
nab911 is offline   Reply With Quote
Old 07-25-2006, 11:16 AM   #74
Mike Wevrick
RIP 1/19/64 - 7/23/11
Scooby Guru
 
Member#: 24654
Join Date: Sep 2002
Chapter/Region: NESIC
Location: saraseager.com
Vehicle:
1957 Taggart Comet
atlasshruggedpart1.com

Default

Of course the AC reduces power; that's basic thermodynamics and there is no way around it.

Quote:
Originally Posted by Chuck H
It's a very noticeable difference between AC on and off at part throttle in a 2.0L WRX. I turn mine off momentarily when getting ready to start from lights and stop signs because it bogs the motor down so much that it's hard to start smoothly. And trying to get the revs up off idle for hill starting with the A/C on takes a ton more throttle than with the AC off.

It may switch off at full throttle, but it's definitely like dragging around a boat anchor in normal driving with small throttle openings.
I do the same thing, and also when climbing hills on the highway.
Mike Wevrick is offline   Reply With Quote
Old 07-25-2006, 11:32 AM   #75
Chuck H
Scooby Specialist
 
Member#: 20442
Join Date: Jun 2002
Chapter/Region: NESIC
Location: Chelmsford, MA
Vehicle:
KTR tuned 2003 WRX
VF34 equipped, 270 whp

Default

Another good way to think about it for the doubters. We all realize that A/C probably only drains 10 or so hp. That doesn't sound like much on a 227 hp car. But look at any dyno of a stock, or even modified WRX. Down around 2000 RPM, they're only making 50 hp or less. Losing 10 of those to the A/C compressor is pretty significant.
Chuck H is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTT Power for Less Power JohnST2k6k Tri-State Area Private Classifieds 0 01-11-2010 03:11 PM
The vain? search for safe, CEL-less power Hedonic Treadmill Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 25 12-31-2001 01:15 PM
Less power? Skunkeye Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 25 07-30-2001 09:20 PM
less power WRXGAL Newbies & FAQs 11 06-22-2001 01:30 AM


All times are GMT -4. The time now is 12:26 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.