high altitude performace
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Instructor
Joined: Sep 2004
Posts: 122
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From: Salt Lake City UT
high altitude performace
i just moved to utah from st. louis and was wandering how to get my performance back. the elevation here is about 6000 feet where st.louis is about 500 feet. can anybody recomend anything that would be cheap and easy to do.
Burning Brakes
Joined: Jul 2004
Posts: 956
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From: Mesquite Nevada
I moved to Utah 2 years ago from Hawaii (sea level) and didn't experiance any noticable power/performance loss. Before moving I was concerned about the change in altitude, but was told the computer would compensate for the change and from what I can tell, it did. I haven't done the 1/4 since being here, but on the road she responds and pulls just like she always has.
Melting Slicks
Joined: Jan 2003
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From: What did the 5 fingers say to the face? SLAP!!
Originally Posted by 87Clwy
I moved to Utah 2 years ago from Hawaii (sea level) and didn't experiance any noticable power/performance loss. Before moving I was concerned about the change in altitude, but was told the computer would compensate for the change and from what I can tell, it did. I haven't done the 1/4 since being here, but on the road she responds and pulls just like she always has.
I bet you would be surprised to find out how much your performance has suffered if you took it to a track. Next time NHRA is running out of Denver, check out how much slower the times are. Altitude plays a huge role in times.
Burning Brakes
Joined: Jul 2004
Posts: 956
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From: Mesquite Nevada
Originally Posted by flyersfan1088
I bet you would be surprised to find out how much your performance has suffered if you took it to a track. Next time NHRA is running out of Denver, check out how much slower the times are. Altitude plays a huge role in times.
Thanks, I'll have to do that if they run between now and December -- I'm moving to AZ curtesy of the Air Force. I'd be curious to find out just how much a difference there is.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by 1fast91
the elevation here is about 6000 feet where st.louis is about 500 feet.
Originally Posted by 87Clwy
I moved to Utah 2 years ago from Hawaii (sea level) and didn't experiance any noticable power/performance loss. Before moving I was concerned about the change in altitude, but was told the computer would compensate for the change and from what I can tell, it did. I haven't done the 1/4 since being here, but on the road she responds and pulls just like she always has.
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Intermediate
Joined: May 2004
Posts: 49
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From: San Diego CA
Keep in mind that you have turbos as well. Since they are compressiong the air they work a lot better at altitude than a naturally aspirated motor. You do lose some power as the oxygen content is less and the turbos have to work harder to achieve the same boost.
I think NHRA adjustment for turbo cars is only 1/2 of what it is for NA cars.
I think NHRA adjustment for turbo cars is only 1/2 of what it is for NA cars.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by 87Clwy
Thanks, I'll have to do that if they run between now and December
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Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by 1fast91
i live up in park city, i was wandering do 90-91 have MAF sensors, wouldnt that change everything.
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Race Director
Joined: Dec 2002
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
I drove my NA Corvette to Salt Lake City last year. I live in San Diego. The car felt like it lost 50hp.
Turbos will compensate for less barometric pressure..in other words if they are set to blow off at 12 psi, they will blow off at 12psi if they are at 4000feet or at sea level...the motor always sees the same intake pressure. For this reason a turbo is THE answer to the altitude problem.
A supercharger will help but will also experience some loss of power at altitude, i.e. if you have driven the blower to provide 5psi at sea level, it will provide something less than 5psi at higher altitudes.
The good thing is that every, non-turbo car at your altitude is experiencing the same power loss.
Larry
Turbos will compensate for less barometric pressure..in other words if they are set to blow off at 12 psi, they will blow off at 12psi if they are at 4000feet or at sea level...the motor always sees the same intake pressure. For this reason a turbo is THE answer to the altitude problem.
A supercharger will help but will also experience some loss of power at altitude, i.e. if you have driven the blower to provide 5psi at sea level, it will provide something less than 5psi at higher altitudes.
The good thing is that every, non-turbo car at your altitude is experiencing the same power loss.
Larry
Race Director
Joined: Sep 2000
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From: The Top of Utah
Just a minor correction. The 12# blow off pressure is a pressure DIFFERENCE. When there is 12# MORE pressure than atmospheric, the pressure overcomes the spring pressure which is aided by the ambient air pressure, and the valve dumps the excess. With the lower pressure at higher altitudes, the boost pressure is lower, also.
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Melting Slicks
Joined: Nov 2003
Posts: 3,375
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From: Northern CA
Originally Posted by 1fast91
would a 58mm bbk throttle body help in componsating for the loss of air through the motor. if not would a fuel pressure regulator help me if i turned down the fuel.
The MAF and computer already do a good job of adjusting the mixture.
You have exactly the same problem as anyone who wants more power at sea level. You need to be able to run more air through your engine. If it won't help you at sea level, it won't help you at altitude.
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by 1fast91
would a 58mm bbk throttle body help in componsating for the loss of air through the motor. if not would a fuel pressure regulator help me if i turned down the fuel.
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Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Indeed going to higher elevation is like having the baro drop at a fixed location...weather can have quite an effect on performance of a NA engine.
Every 1,000 ft of elevation will cost you abut 3% in CHP. So the change of 5,500 ft will cost about 16.5% or 40chp on a 240chp L98.
If your L98 is now bone stock, that loss is pretty easy to gain back with some simple bolt-ons.
Every 1,000 ft of elevation will cost you abut 3% in CHP. So the change of 5,500 ft will cost about 16.5% or 40chp on a 240chp L98.
If your L98 is now bone stock, that loss is pretty easy to gain back with some simple bolt-ons.
Le Mans Master
Joined: Jan 2000
Posts: 6,595
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From: Thornton CO
Originally Posted by 65Z01
If your L98 is now bone stock, that loss is pretty easy to gain back with some simple bolt-ons.
Not at 6000'. I live in Denver and our track is at 5800' and some simple bolt on's will not get you back on track. At our altitude you lose somewhere between 17-20% on any given day. The only bolt on's that are going to give you that back are superchargers. My dad's Grand Sport dynoed at 249 uncorrected and 292 corrected for sea level. The correction that day was 17%.