I've notice when i visit the lower elevations that my car gains a very noticeable amount of power, I feel like moving! I live 4,000 up in the Desert, When i get anywhere near below 500, The car just flys, I've got some internal work done to the car$$$ but it so comes alive when i'm down below, I have a race car that loves the cold air, The cold shows no significant difference with the cold air change, but it favors lower elevations, It's like night and day, Is it me or Meds need upping?

I've notice when i visit the lower elevations that my car gains a very noticeable amount of power, I feel like moving! I live 4,000 up in the Desert, When i get anywhere near below 500, The car just flys, I've got some internal work done to the car$$$ but it so comes alive when i'm down below, I have a race car that loves the cold air, The cold shows no significant difference with the cold air change, but it favors lower elevations, It's like night and day, Is it me or Meds need upping?

Nope, it isn't you, it is your car lovin' the denser air. Being computer controlled, and with computer constantly monitoring the A/F ratio, when a denser air is available, the computer will allow more fuel, Hence, more HP!

Going from 4000 ft to 500 ft, you will gain almost 4 inches of manifold pressure. A normally aspirated engine loses approximately
3.5% hp per 1000 feet increase in higher DA (density altitude) When we say higher density altitude, we mean less dense air that would be at a higher altitude, or higher temperature, or more humid air, and most likely a combination of all of the aforementioned.

air is more dense at lower elevations. Make sense that it is what you are also trying to do with forced induction (get more dense air into the combustion chamber).
Could also be your meds as well....

Lol!!!
Thanks guys, I wanted to ask a while ago, But had to be a 100% sure.

Cheers,

A normally aspirated engine loses approximately
3.5% hp per 1000 feet increase in higher DA (density altitude).

Ed,

Just for my education, could that power loss be related to the compression of the engine as well? Like the M73 with 10:1 will lose less than the M70 with 8.8:1?

no, it shouldn't matter since it is dependant on air density, not engine compression.

Ed,

Just for my education, could that power loss be related to the compression of the engine as well? Like the M73 with 10:1 will lose less than the M70 with 8.8:1?

no, it shouldn't matter since it is dependant on air density, not engine compression.

Isn't if more of a matter of cylinder pressure, which is based on compression, because with a cold air intake, forced induction, nitrious, etc the engine is getting a higher cylinder pressure which gives more power. So I would think since the M73 has a higher cylinder pressure than the M70 to begin with it would lose less power in the higher elevations where there would be less air to power the bang.

Isn't if more of a matter of cylinder pressure, which is based on compression, because with a cold air intake, forced induction, nitrious, etc the engine is getting a higher cylinder pressure which gives more power. So I would think since the M73 has a higher cylinder pressure than the M70 to begin with it would lose less power in the higher elevations where there would be less air to power the bang.

Abit confused to your meaning, BUT, you can not link forced induction and nitrous to normally aspirated engines with ambient air pressure and temperature with power loss.

In a normally aspirated engine, it make no difference what the compression ratio is, cam overlap, ignition timing, or other internal parameters to power loss with increasing density altitude. The % loss , high compression, low compression, doesn't matter, will follow the same loss ~ 3.5% per 1000 foot DA increase. This also make an assumption that the fuel is being adjusted to optimal values based on density altitude.

Further, if forced induction is used, the turbo or supercharger will have to work harder to maintain boast if outside air density is reduced so, broadly said, turbos will maintain HP up to a certain DA with less drop then supercharged engines because turbos recover waste heat whereas superchargers are belt driven and take engine power directly from the crank. There will still be some loss with increasing DA but not as dramatic as in normally aspirated engines until critical altitude is reached, more heat is produced in the turbo or supercharger, (it is working harder to compress the air) and the cooling effects of the intercooler, if used, is less with increasing DA.

Nitrous isn't in the equation, a couple of squirts and you are done! :)