Starting the twin install...

[John S.]

No updates. Just been driving the car and enjoying the power!!!

Bad news is they pulled out E85 from my town so I am at a big crossroads on the car... Dunno what to do yet

That sucks! I guess it's time to move.

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[Legionofone]

Just a FYI, you shouldn't see much of any change when you come to sea level. 11LBs of boost at 6K feet is the same as 11 at 0. You may actually go faster up there due to reduced wind resistance. Turbos are good at compensating for altitude that NA cars cant.

 

[Kryckter]

Just a FYI, you shouldn't see much of any change when you come to sea level. 11LBs of boost at 6K feet is the same as 11 at 0. You may actually go faster up there due to reduced wind resistance. Turbos are good at compensating for altitude that NA cars cant.

You'd be surprised how big of a change it is. I've been racing boosted cars at high altitude for many of years. Yes 11lbs of boost is the same amount of pressure at high altitude and sea level. But the amount of Oxygen up here is significantly less... The cars make alot more power when you get down to sea level.

 

[Legionofone]

O2 ratio should stay roughly the same at 80 Nitrogen 19 Oxygen 1% other. You do gain in spool time and everything works a bit easier to make the 11lbs but the engine at max power should be like for like.

 

[Grandfunk]

O2 ratio should stay roughly the same at 80 Nitrogen 19 Oxygen 1% other. You do gain in spool time and everything works a bit easier to make the 11lbs but the engine at max power should be like for like.

The ratios of the gasses in air are relatively the same but the available oxygen molecules for combustion for a given volume is different. There is more oxygen per cubic foot at sea level than there is at 6k feet due to the differences in atmospheric pressure.

Air is more dense at sea level and thusly the 19% portion of that air that is oxygen has more molecules total. Would you rather have 19% of ten thousand dollars or 19% of one hundred? They are not equal.

In other words if I pressurize a cylinder with air to 10 psi and another to 100 psi which one has more oxygen? The ratios amongst the contained gasses are the same but the cylinder at a higher pressure has more total oxygen. It is at a higher pressure and the gas is more dense.

Pressure and density changes of altitude have a similar effect. Less atmospheric pressure, less oxygen, less engine power for a given air flow. The boost pressure being the same does not negate the fact you have less oxygen. In fact, you would need a higher boost at higher altitude to make the same power due to the fact you have to force more air in to even out the lower O2 concentration.



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[Inigo]

You'd be surprised how big of a change it is. I've been racing boosted cars at high altitude for many of years. Yes 11lbs of boost is the same amount of pressure at high altitude and sea level. But the amount of Oxygen up here is significantly less... The cars make alot more power when you get down to sea level.

Absolute pressure, yes. Thats the nice thing about a turbo is that you can spin it to produce the same absolute boost at elevation vs sea level. The downside is that it takes more out of the turbo to do it. Us supercharged guys don't have that luxury. The same pulley at sea level will produce less boost at elevation. We have to pulley down a size or two to get back whats lost. On top of that, we end up putting more tax on the unit which produces more heat. Even the fuel hates high elevation. Fuel vaporizes at a lower temperature at high elevation.

 

[Chameleon]

And the video

Hahahah! Warp speed!

 

[Adaraas]

What boost controller are you using?

Looking to do this for myself and I'm a bit lost on the boost controller.

 

[CM581978]

Wayyyyyy overdue for new vids

 

[PowerAdderGT]

Love it!

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