High Altitude 1ers

[sargetony]

Hello fellow Coloradans,

I have a few questions for you guys that have tuned your cars for Colorado's altitude. I live in Colorado Springs, so at an altitude of 6,200ft.

Just to set the baseline, I have an 08 135i with a JB3 (will be JB4 when I get back from Afghanistan) and a CAI. That is the only mods to the engine so far. I am looking at adding Meth once Terry finishes their new meth kit that fits under the hood. I have also been looking at DPs, but this going to be later down the road.

Now, on to the questions!

- Is there anything special I need to be aware of because of our altitude? i.e. need to not strive for 16psi because the turbos are already working hard due to thin air...
- Are there any special precautions that need to be taken to prevent excessive wear and tear? i.e. a FMIC is a necessity.
- Does anyone in the Springs area know where I can find 93 Octane gas down by Ft Carson?
- I am sure I am missing something, but for the life of me, I can't remember everything I thought of last night...

Thanks in advance for your answers.

[pwdrtoastman]

Hello from Afghanistan, 1st BDE.

There is no 93 octane in the area the elevation creates a enviroment where you don't need that much octane for spark (stock) so gas stations don't sell it. E85 is out of the question becuase of the DI.

If your really worried about it buy a octane booster, research and find which one is actually effective.

The acutally percentage of oxygen doesn't change, there is literally just less dense air for you car.

I forgot exactly but your car loses 4% whp per 1000ft of elevation, that puts us at 23-26% power loss.

A fmic will just cool the incoming air charge, it will make it more dense, but i don't think it will make a difference from a safety stand pont (elevation). It will help with power, plus its a good idea as soon as you increase boost.

I'm new to the these cars, but i'm definately not new to tuning and direct injection.(500whp evo on e85)Your best bet is get a custom flash for you set up.

i'm sure our ecu's learn based on air density and adapt to the elevation, this is assuming all of your cars sensors or working properly. The fuel table goes from lean to rich as load increases. At higher altitudes you will not generate the same load values. They will be lower (due to lower MAF voltage readings). Thus, the fueling will be leaner. That's just a function of load and the fuel map.

You might want to look into how the JB4 effects the ecus ability to adapt.

I will be home soon, we should link up, hit me up on pm

[sargetony]

Sweet.

BTW, I am in 1BDE too. I am at CNS.

Thanks for the insight. I hit em up on N54tech.com as well and one of the guys up in Denver had some really good points as well. Talking to Terry over there, he talks as if everything will be fine with the JB4.

However, the turbos are definitely working harder to make the same amount of boost, something to the effect of increasing by 3.5lbs at our altitude. So 12psi of boost requires the turbos to work as if they were putting out 15.5psi.

I am a turbo noob, my past experiences have always been with NA cars. This one is my first turbo.

[pwdrtoastman]

pm with any turbo questions you have this is my 5th turbo'd car.
i'm at stone