Air conditioning and horse power
Air conditioning and horse power
06-04-2002, 11:43 AM
#3
Whatever it is, there are times when it is worth it.
I remember the last time running at thunderhill, near sacramento, we say 100+ degree temps. Thank goodness that I could run the AC while I was on the track.
Jeff
I remember the last time running at thunderhill, near sacramento, we say 100+ degree temps. Thank goodness that I could run the AC while I was on the track.
Jeff
06-04-2002, 11:48 AM
#4
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Does Porsche have an A/C compressor cut-off when you mash your foot in the throttle?
06-04-2002, 12:55 PM
#6
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Jeff, easy for you to say when you have 400 HP under your foot. 
I really feel that 10-15 horses is about what I feel when driving with the A/C on.
I am cuirous to know exactly what functions is changed with the DME when the A/C button is pushed? I know that the throttle is a little higher, but anything else? Like is there any changes to the ignition timing?
I really feel that 10-15 horses is about what I feel when driving with the A/C on.
I am cuirous to know exactly what functions is changed with the DME when the A/C button is pushed? I know that the throttle is a little higher, but anything else? Like is there any changes to the ignition timing?
06-04-2002, 01:46 PM
#7
RL Technical Advisor
Hi Robin:
I don't know if I can help or not but I'd simply shed some light on your questions,.....
First, all of the Sanyo and Sanden rotary compressors that we have checked on the dyno have generated a 10-12 HP loss when the compressor clutch is engaged. Belt tension accounts for some variations here.
Second, the ECU doesn't change timing or fueling when the compressor is running, only hot idle speed.
Hope this helps a little.
I don't know if I can help or not but I'd simply shed some light on your questions,.....
First, all of the Sanyo and Sanden rotary compressors that we have checked on the dyno have generated a 10-12 HP loss when the compressor clutch is engaged. Belt tension accounts for some variations here.
Second, the ECU doesn't change timing or fueling when the compressor is running, only hot idle speed.
Hope this helps a little.
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06-04-2002, 01:52 PM
#8
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[quote]Originally posted by Terry Adams:
<strong>Does Porsche have an A/C compressor cut-off when you mash your foot in the throttle?</strong><hr></blockquote>
Yes.
<strong>Does Porsche have an A/C compressor cut-off when you mash your foot in the throttle?</strong><hr></blockquote>
Yes.
06-04-2002, 02:21 PM
#9
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Steve,
As always, your answer provided 100% of the data that I was looking for.
Now, the million dollar question is:
(1). Is there a more efficient compressor unit that will use less horse power?
(2). Would it help any to fit a smaller diameter pulley unit, who makes such a device?
As always, your answer provided 100% of the data that I was looking for.
Now, the million dollar question is:
(1). Is there a more efficient compressor unit that will use less horse power?
(2). Would it help any to fit a smaller diameter pulley unit, who makes such a device?
06-04-2002, 03:46 PM
#10
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Robin - 911s have AC? I thought that climate control deal was for the engine - to draw heat away and into the cabin. On the other hand, the AC in my 993 does work better than the AC in my 930 - which is basically non-existent if not hotter than outside.
Why don;t you just remove the whole deal and save some weight while you are at it.
Why don;t you just remove the whole deal and save some weight while you are at it.
06-04-2002, 04:07 PM
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ZCAT3,
That's is just not possible in Georgia weather....
If I was in California I would remove the A/C.
Like today..... 91 degrees with 50% humidity
And my 993 feels so dog gone slow today.
That's is just not possible in Georgia weather....
If I was in California I would remove the A/C.
Like today..... 91 degrees with 50% humidity
And my 993 feels so dog gone slow today.
06-04-2002, 07:01 PM
#14
Although the debate as to how much horsepower may be lost by A/C could be a protracted one as it also entails issues of what HP lost at what piont and for how long, there are two other costs of A/C, one to cars in general and the other to Type 993 and Type 964 in particular.
The first is the weight penalty, particularly as certain of that weight is in the rear and high. The second and, and perhaps not so obvious, is the fact that the placement of the compressor on Type 993/964 prevents the use of slide valves which could produce noticeable performance improvements. In other words, if one were concerned about performance above all else, this debate would be short and the A/C would be gone. In the real world, however, I would keep it and find other ways to improve performance.
The first is the weight penalty, particularly as certain of that weight is in the rear and high. The second and, and perhaps not so obvious, is the fact that the placement of the compressor on Type 993/964 prevents the use of slide valves which could produce noticeable performance improvements. In other words, if one were concerned about performance above all else, this debate would be short and the A/C would be gone. In the real world, however, I would keep it and find other ways to improve performance.