|
|
|
|
| Author |
|
|
Registered
|
Motor driven ac compressor btu output and hp needed
Anyone know the btu output of a motor driven 911 ac compressor? Also what hp is required to operate it at maximum output?
|
||
07-27-2023, 04:21 PM
|
|
|
PCA Member since 1988
|
On a related thread, someone indicated that the Classic Restoration compressor draws about 80 amps when running. Let's use that as a representative example.
80A x 14V = 1160 watts. 1160W = 1.55HP. Add 10% for conversion losses, and it should take about 1.7 HP to run the compressor.
__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners. Cars are for driving. If you want art, get something you can hang on the wall! |
||
|
07-27-2023, 10:58 PM
|
|
|
Original Owner
Join Date: Dec 2002
Location: San Antonio, Texas
Posts: 1,907
|
Depends on the compressor. I run a SD5H14 8ci
This is pretty similar. Right at 7kW max so closer to 8-10hp. I see a 50RPM drop when I turn the AC on at idle so my idle is set somewhat higher to compensate. On my turbo I don't feel that loss...but I do like the mid 30s vent temps! Most peeps don't go this big.... but you need kW to cool.  
__________________
tsuter 78 911SC Turbo Targa Thaaaats Right!! |
||
|
07-28-2023, 06:16 AM
|
|
|
Get off my lawn!
|
Just seat of the pants feel and no science at all:
I have the factory stock style of compressor, the Nippendenso. It is new as I wore out the the second one after many years of use. Anyway, my idle does not change at all with the compressor cycling on or off at idle. I do not really notice it in driving, but I do understand, yea, it is using some HP to compress the refrigerant and make cold air for the cabin. I would have to guess, maybe a few HP, but not a lot. And my AC system if the full boat, Mr. Ice setup from Griffith's with 4 condensers, and extra vents, and added knee vents for the tiny 85 Carrera side vents. I can get 37 degree air blowing at the MAX hurricane speed when it is 107 outside after a 11 hours of driving, or just 10 to 15 minutes after sitting for an hour in the sun. I don't worry about the HP loss as it is minor.
__________________
Glen 49 Year member of the Porsche Club of America 1985 911 Carrera; 2017 Macan 1986 El Camino with Fuel Injected 350 Crate Engine My Motto: I will never be too old to have a happy childhood! |
||
|
07-28-2023, 06:47 AM
|
|
|
Original Owner
Join Date: Dec 2002
Location: San Antonio, Texas
Posts: 1,907
|
Correct. The stats I posted for that big Sanden are at MAX RPM. That's almost never so the normal HP drag depending on compressor is in the range of 3-6. Who cares....
__________________
tsuter 78 911SC Turbo Targa Thaaaats Right!! |
||
|
07-28-2023, 07:58 AM
|
|
|
Registered
|
I think it might even be less than 3-6 HP with the stock Nippon Denso.
The small magnetic clutch draws only 3 amps and I doubt it would pass the torque required for 6 HP (that is more than 4kW). My compressor belt is not even tight and I never hear it squeal when AC is on.
__________________
Gilles RoW 88 Carrera coupé |
||
|
07-28-2023, 09:19 AM
|
|
|
|
Registered
|
If i use an electric compressor say keep it in the rear with stock everything then 3 hp to 6 hp? Up to 372 amps?
Guess that is not going work as i would a 500 amp alternator? |
||
|
07-29-2023, 09:47 AM
|
|
|
Registered
Join Date: Jul 2013
Location: South East England
Posts: 1,692
|
Quote:
__________________
www.classicretrofit.com |
||
|
07-30-2023, 11:09 AM
|
|
Carrera
88 Carrera coupé
