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jlebrun_05
Active member
my roommates and I were argueing whether a turboed 4 stroke fuel injected sled lose horsepower at high elevations, or will it keep the same horsepower?
Help, solve an arguement in our house
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BadAftertaste
Well-known member
That depends on whether boost is constant as well as air charge temperature.
it will lose power if you leave it at the same boost level, it won't lose power as drastically as a naturally aspirated motor though.
the boost pressure is pressure over atmospheric, which is less as you go higher, so therefore you have less pressure, or more importantly, less CFM.
Change the boost with your elevation though, and then you can run the same power at 10,000feet as you do at 5000 feet.
the boost pressure is pressure over atmospheric, which is less as you go higher, so therefore you have less pressure, or more importantly, less CFM.
Change the boost with your elevation though, and then you can run the same power at 10,000feet as you do at 5000 feet.
HP goes down due to lower atmospheric pressure...less air in the combustion chamber of a N/A motor. A turbo motor with a waste gate allows the turbo to build a certain amount of pressure....regardless of elevation. I believe there is a VERY SLIGHT drop in HP due to the VERY SLIGHTLY lower O2 levels at higher elevs, but for all intents and purposes, the turbos do not lose HP.
N.A. 3%
Turbo. .5%...and then you can still turn the boost up so you can always be running at top
Turbo. .5%...and then you can still turn the boost up so you can always be running at top
The MCX kit will compensate for altitude by controlling boost but the bottom line is, Every engine will make less power the higher it goes
It's Physic's
It's Physic's
if you have a big enough turbo that is able to do the extra work then you can just dial away and your safe, but if you have one that is spinning its heart out trying to produce the boost you need, then the extra work up high is gonna make it to far on edge, and you may ruin turbo.
some simple math, anyone correct if im obviously wrong.
fictional settings both running 10 pounds of boost.
sea level-14.7+10psi = 24.7
10,000-10.2 psi+10psi = 20.2
you cant affect the pressure of the atmosphere, but you can affect the boost your turbo is making, you have to run approximately 4.5 more PSI on the turbo at 10,000 feet than at see level to make the same power.
some simple math, anyone correct if im obviously wrong.
fictional settings both running 10 pounds of boost.
sea level-14.7+10psi = 24.7
10,000-10.2 psi+10psi = 20.2
you cant affect the pressure of the atmosphere, but you can affect the boost your turbo is making, you have to run approximately 4.5 more PSI on the turbo at 10,000 feet than at see level to make the same power.
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