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curious
Dodge Dakota
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5/26/2004
19:07:46
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 Subject: silly elevation question
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ok,a question for any science buffs that may be out there.would an increase of 900ft in elevation effect the way a car performs?
where we live in texas the elevation is about +1900.where he bought the car the elevation is about +1000.he drove it back and said it didnt run the same(became kinda slugish)when he got closer to here.he traveled about 1100 miles.
for anyone keeping score its a 2000 SS camaro.we raced at a slower highway speed and i pulled on him,i have a 2002 Z28.i wouldnt have thought i would beat him so we have been trying to figure out why.is the elevation thing plausible?
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another mark
Dodge Dakota
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5/26/2004
19:16:21
| RE: silly elevation question
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Yes it is elevation related. The air gets thinner (less dense) and any internal combustion engine is going to have an anemic reaction to less air pressure. Basically an engine is a giant air pump. As you starve out that air supply you hamper it's ability to make power. Ever try putting your hand over the top of a carb with the air cleaner off while it ran? You'll stall it.
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.boB
Dodge Dakota
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5/26/2004
19:19:23
| RE: silly elevation question
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Yes, there is a differance. But, with only a 900 foot change, I wouldn't expect a dramatic/noticable change in a car like that. I don't notice much of a change in my Dakota untile 1500-2000 feet or so. I'd look at other things pretty closely before writing it off as altitude. Could be just a tank of bad gas. You know, regular in the premium pump......
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ParkCityKota
Dodge Dakota
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5/27/2004
11:24:59
| RE: silly elevation question
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I moved to Utah from Boston about 3 years ago and experienced a 6,000+ foot elevation change...definately a noticable difference. I posted a question about this a few weeks ago and someone replied that it's Boyle's Law of Gasses in action. For every 1,000 feet you lose about 2-3% horsepower. 900 feet aint gonna do much so I'd look elsewhere. If you're talking a couple thousand than that's a different story. When I go down to the Salt Lake City valley I notice my truck running different than when I'm at home which is only 20 miles away but about 3,000 feet higher than SLC.
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another mark
Dodge Dakota
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5/27/2004
12:21:47
| RE: silly elevation question
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I'd love to hear the final answer on this one.
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99DAK
Dodge Dakota
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5/27/2004
12:59:56
| RE: silly elevation question
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The 3% HP loss per 1000ft is derived from the established 3% decrease in air density per 1000ft increase in altitude.
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ummm
Dodge Dakota
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5/27/2004
13:19:23
| RE: silly elevation question
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regardless of the effect altitude plays on an engine, both vehicles would suffer the same handicap.
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curious
Dodge Dakota
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5/27/2004
14:20:56
| RE: silly elevation question
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i bought mine here so i wouldnt have the handicap.its funny,we went out "playing" last night and he spins too bad to tell off a stop but from any good speed 40+ i pull on him.i raced a vtech prelude(yeah wow!) and killed that and i raced a 2001 trans am and pulled him really well too.we did that one on a 4 lane and once my buddy caught traction he pulled on the TA.he got to race a lancer evo and with the traction control on he got beat off the line but pulled hard on the guy and won.i didnt get to race the evo,but he was running 13.8s at the track in it two weeks ago.and i know that car is supposed to run faster than that.
so i dont know,i couldnt get my buddy to race me with his traction control on,so who knows?i guess we will see on the 4th,thats when the track is open again.
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Kowalski
GenI
5/27/2004
15:38:10
| RE: silly elevation question
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There's kind of a double whammy to increased elevation; less O2 to burn, and lower compression. But elevation will affect both, so that's probably not what you're seeing. If your cam is more tolerent to lower compression, might be part of the difference though.
Lead, follow, or get out of the way
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Chiz
Dodge Dakota
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5/27/2004
20:01:17
| RE: silly elevation question
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Curious: Unless I'm sorely mistaken, both vehicles would indeed have the same handicap. The fact that you bought your vehicle at a higher elevation has no effect on it's potential output. Basically, 1900 ft. is 1900 ft.
What I'm impressed with is that a Z28 is beating an SS.
My experience with elevation: when I took my Dakota from the Pacific Ocean to Denver I could feel a huge difference in performance, especially over the tops of the Rockies. I think it's something like 11,007 feet at the Eisenhower Tunnel, so climbing the hill to get there was no easy chore for my 3.9L, but it got there at 60mph+ the whole way.
Even in Denver though (~5,000 ft.) the change from normal was very noticable (and frustrating). I looked at some car trader magazines out there and almost all of the trucks for sale (of any brand) had the biggest available engines in them. I guess that's because the difference in altitude has that much of an effect on performance, so in the higher altitudes that is just what has taken hold.
But 900 ft.? I'm not so sure. Keep winning those races though (safely)!
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01Motorsport
Dodge Dakota
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5/27/2004
20:28:14
| RE: silly elevation question
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Temperature and humidity figure into any performance equation as well. Bristol Dragway in upper east Tennessee is at about 1000 ft., yet several world quarter mile records are set there. I was in Denver a few years ago, and was curious about the 85 octane fuel sold in Colorado? The Chevy Monte Carlo rental car we drove around Breckenridge, Colorado Springs, Golden and Independence Pass was a pinging s.o.b..
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Kowalski
GenI
5/28/2004
08:14:46
| RE: silly elevation question
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They sell lower octane at higher elevations because many vehicles can run it with the effectively lower compression.
Lead, follow, or get out of the way
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01Motorsport
Dodge Dakota
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5/28/2004
08:34:47
| RE: silly elevation question
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Of course, the consumer never sees the cost reduction at the pump price of 85 octane.
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.boB
Dodge Dakota
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5/28/2004
10:14:13
| RE: silly elevation question
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As I understand it, the octane rating varies with altitude because of the way it's calculated, and not the way it's formulated. The 85 octane stuff you buy here in CO is essentially the same octane wise as the 87 stuff you buy in TX.
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curious
Dodge Dakota
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5/28/2004
15:39:54
| RE: silly elevation question
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my buddy seems to think that his computer is learning to adjust to the change,i guess that makes since.what i meant by me not having the handicapp is that my car is already adjusted to the elevation/climate.i dunno,maybe my car is one of those you hear about being hopped up from the factory randomly.
my friends dad has a 2003 C-5 vette and i guess im gonna race him this weekend to see if there are any surprises,at the very least i need to finally get beat.im still looking for some lightenings,those things used to pick on me when i had my r/t,now its my turn!
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Kowalski
GenIII
5/29/2004
06:15:52
| RE: silly elevation question
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.boB - I don't think you understand correctly - it really is a lower octane; it works at higher altitudes because cylinder pressures are lower due to thinner air and thus less apt to knock. The pump should say how its calculated, if you'd like to compare.
Lead, follow, or get out of the way
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.boB
Dodge Dakota
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5/29/2004
08:43:54
| RE: silly elevation question
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You're probably right. I'm not a chemist. But that's how it was explained to me at the Dodge dealership when I first moved here to CO. Shows how much I know :)
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matwood
Dodge Dakota
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5/29/2004
11:11:16
| RE: silly elevation question
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i frequently drive from an elevation of 2900 to 6200 in about 20 miles and dont notice a change. it still pulls hard and goes fast up those hills. i have a 94 5.2 4x4 CC 3.55
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curious
Dodge Dakota
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6/03/2004
13:31:42
| RE: silly elevation question
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just in case anyone cares,i found the answer.i dont beat him because of elevation,or that he needs a tune up.i ended up getting a link to email a guy who used to be a gm techie in their "performance division".
he said that the 02 camaros were very under rated from the factory basically to make the c-5s look good.he said z28s came out rated at either 310or335hp,but really they are closer to 360hp!my buddy went to a few message boards and asked about this and they said it too.im happy with this answer.he also said that a stock 2000 SS was good for about 330 or 340hp.i guess that explains me pulling on him.
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Chiz
Dodge Dakota
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6/04/2004
00:37:23
| RE: silly elevation question
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Sounds like you got lucky. Sweet.
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curious
Dodge Dakota
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6/06/2004
15:32:43
| RE: silly elevation question
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i was really happy when i found that out.i took it to the track friday,and man,i need tires!i was spinning something aweful and i couldnt even launch.i ran a best 13.92@101mph.my buddy ran a best of 14.001@99.25 mph.its weird,i yank him by about 2 car lengths on the street but i couldnt get traction on the strip.oh well.the mod bug is about to hit anyway,and im sure that will include a set of slicks to play at the track.
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