I read some place that you lose about 4% of your horsepower, on the average, per thousand feet of altitude. Denver = 5,000 feet or 20% power reduction.
Altitude??
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From: Leesburg, VA
Altitude??
Ok....just drove my 1998 conv...48K miles from KY to Denver.... prior to leaving KY..I installed a new K&N filter kit...Drove for about a week.... couldnt really tell much diff....but can hear the air sucking more...
Anyway....so I get to Denver...and the car just does not perform like it did in TX and then in KY... Just seems sluggish... At first...I thought it was just because the car had just been driven the latter 1/2 of the trip...9hrs....tires were nice and sticky...but a few days later...is noticeably sluggish..
Is 48K too early to replace plugs? Any other thoughts...
Anyway....so I get to Denver...and the car just does not perform like it did in TX and then in KY... Just seems sluggish... At first...I thought it was just because the car had just been driven the latter 1/2 of the trip...9hrs....tires were nice and sticky...but a few days later...is noticeably sluggish..
Is 48K too early to replace plugs? Any other thoughts...
Le Mans Master
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From: Russellville, Kentucky 1967 Sting Ray & 2001 C5
Le Mans Master
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From: Phoenix AZ
Yeah, short of a supercharger or turbo, you are just gonna be down on power. Its amazing how much it robs you.
I drove through Wolf Creek Pass in Colorado once on my GSXR-600 (carbureted) and at over 10,000 feet high, my bike barely ran. It was making 40% less hp (95 hp in Phoenix) and that was if I had leaned out the jetting. It was running sooooo rich, black smoke was coming out and I was making maybe 35-40 hp. Had to stop at the top for construction and had to rev to 12,000 rpm just to get it going. It even started to misfire till I started to go down hill.
I drove through Wolf Creek Pass in Colorado once on my GSXR-600 (carbureted) and at over 10,000 feet high, my bike barely ran. It was making 40% less hp (95 hp in Phoenix) and that was if I had leaned out the jetting. It was running sooooo rich, black smoke was coming out and I was making maybe 35-40 hp. Had to stop at the top for construction and had to rev to 12,000 rpm just to get it going. It even started to misfire till I started to go down hill.
Drifting
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From: Alamosa CO
I live at over 7500' elevation, so my Z is losing 22.5% of it's sea level power.
Melting Slicks
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From: Longmont Colorado
Yeah i live here in colorado and we have a race track (bandimere speedway) where they tell you that your quarter mile times will be 0.934 of a second slower than it would have been at sea level.
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From: Boise ID
Burning Brakes
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From: Mt Isle Harbor NC
I too moved up from the south. It pains me everyday to know that I am missing 80 to 90 hp. Wait until you get into the mountains! Now you are out nearly half of your horsepower!
The dyno shops around here will tell you around 19% to 20% hp loss in Denver for N/A cars and only around 5% powerloss for F/I cars.
The dyno shops around here will tell you around 19% to 20% hp loss in Denver for N/A cars and only around 5% powerloss for F/I cars.
Burning Brakes
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From: Colorado Springs, Colo., USA
I too moved up from the south. It pains me everyday to know that I am missing 80 to 90 hp. Wait until you get into the mountains! Now you are out nearly half of your horsepower!
The dyno shops around here will tell you around 19% to 20% hp loss in Denver for N/A cars and only around 5% powerloss for F/I cars.
The dyno shops around here will tell you around 19% to 20% hp loss in Denver for N/A cars and only around 5% powerloss for F/I cars.
As to mountain driving, at least most everything else is equally low on power, so the Corvette still shines. Unless we run across the big engine diesel pickups with their turbos. Those guys are a pain in the a**, because they use that big power without having handling and brakes to match.
Burning Brakes
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From: Colorado Springs, Colo., USA
Hey, Blue Blood, where did you get that? Up here our gas is already lower in octane: premium is 91. Are you saying go to the mid-range, which is 87?
Interesting thought, I just want to know the genesis of it.
Thanks.
Interesting thought, I just want to know the genesis of it.
Thanks.
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From: Leesburg, VA
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From: Plano TX
higher altitudes mean less oxygen in the air = less power.. I remember ,as a kid. My dad drove through Eisenhower Pass. just west of Denver.. altitude is around 10,000 feet.. 1971 Cutlass 455 c.i. engine.. Struggled to make through that pass... Lower Octane Fuel Burns much better, in high altitude, low oxygen air... Exactly the opposite of what you would think.
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St. Jude Donor '08-'09-'10-'11-'12-'13, '15,'21
higher altitudes mean less oxygen in the air = less power.. I remember ,as a kid. My dad drove through Eisenhower Pass. just west of Denver.. altitude is around 10,000 feet.. 1971 Cutlass 455 c.i. engine.. Struggled to make through that pass... Lower Octane Fuel Burns much better, in high altitude, low oxygen air... Exactly the opposite of what you would think.
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From: Albuquerque NM
Here in Albuquerque I live at 5300' and some of the spots I race are above 6500'. I always use the 91 (or 90 in some cases...) octane because the corvette runs hotter than I am used to with previous cars. By comparison I ran my 99 Miata always on 87 octane, even at the track. I did a lapping sessions comparing and the 91 versus 87 made no difference. The Miata is a low compression car that runs very cool in comparison to the C5. YMMV.
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From: Grand Junction CO
Correct, Redlyner, far less power loss at altitude for forced induction cars. Here in Colorado Springs, my C5 is down about 18%.
As to mountain driving, at least most everything else is equally low on power, so the Corvette still shines. Unless we run across the big engine diesel pickups with their turbos. Those guys are a pain in the a**, because they use that big power without having handling and brakes to match.
As to mountain driving, at least most everything else is equally low on power, so the Corvette still shines. Unless we run across the big engine diesel pickups with their turbos. Those guys are a pain in the a**, because they use that big power without having handling and brakes to match.