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You lose 3% horsepower for every 1000 feet

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Old 04-19-2009, 05:46 AM
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Have any of you actually tested the % of loss of your horsepower as you move to higher sea level? Manufacturers publish a 3% HP loss for every 1,000 feet of elevation as a rule of thumb. For me, that represents an 18% loss of horsepower or just under 60 hp loss on my 300 horses. When I drive to the top of Pikes Peak (14,100') it represents a whopping 42% loss -about a 126 hp loss.
Old 04-19-2009, 06:22 AM
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Originally Posted by juris335' post='851650' date='Apr 19 2009, 09:46 AM
Have any of you actually tested the % of loss of your horsepower as you move to higher sea level? Manufacturers publish a 3% HP loss for every 1,000 feet of elevation as a rule of thumb. For me, that represents an 18% loss of horsepower or just under 60 hp loss on my 300 horses. When I drive to the top of Pikes Peak (14,100') it represents a whopping 42% loss -about a 126 hp loss.
Damn could it really be THAT much? Do you feel the horse power loss up there?
Old 04-19-2009, 07:21 AM
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Originally Posted by Krozi' post='851663' date='Apr 19 2009, 10:22 AM
Damn could it really be THAT much? Do you feel the horse power loss up there?
There is definately an HP loss. I don't think its that much. It's probably = to the % loss of oxygen at higher altitudes. Thats for NA engines only, forced induction could maintain the max HP at much higher altitudes.

However, per this web site: Altitude Presure Calculator, at 14,100 ft (4300 m) you're down to 60% O2, 3% per 1000, and probably a 40% loss in HP.
Old 04-19-2009, 07:48 AM
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Yup!

That's why almost all the Pikes Peak Hill Climb contenders uses forced induction (especially the top front runner) to break the record of Race to the Cloud.

So, OP ... don't worry your car is set!
Old 04-19-2009, 07:57 AM
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Originally Posted by juris335' post='851650' date='Apr 19 2009, 08:46 AM
Have any of you actually tested the % of loss of your horsepower as you move to higher sea level? Manufacturers publish a 3% HP loss for every 1,000 feet of elevation as a rule of thumb. For me, that represents an 18% loss of horsepower or just under 60 hp loss on my 300 horses. When I drive to the top of Pikes Peak (14,100') it represents a whopping 42% loss -about a 126 hp loss.
It doesn't surprise me. I used to live in Steamboat Springs, and the cars definitely would be wheezing as we topped Rabbit Ears pass (~7K').
Old 04-19-2009, 08:04 AM
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Hehehe I live at sea level
Old 04-19-2009, 08:13 AM
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Originally Posted by Krozi' post='851710' date='Apr 19 2009, 11:04 AM
Hehehe I live at sea level
Now if only we could do something about that humidity, then we would really be making some power!

All those numbers sound about right, but hey, it could be worse, at least we aren't using carburetors still.
Old 04-19-2009, 08:19 AM
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Originally Posted by 305bimmer' post='851712' date='Apr 19 2009, 12:13 PM
Now if only we could do something about that humidity, then we would really be making some power!

All those numbers sound about right, but hey, it could be worse, at least we aren't using carburetors still.
Yea, I remember the cold mornings when I drove to school man you could really feel some more power. Now the heat and humidity is robbing my horses
Old 04-19-2009, 10:44 AM
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So at 6 ft below sea level, my car is faster than yours!!
Old 04-19-2009, 11:13 AM
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Originally Posted by kscarrol' post='851827' date='Apr 19 2009, 01:44 PM
So at 6 ft below sea level, my car is faster than yours!!
Hahaha. But you have to factor in that you have to go up hill to catch him


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