98Zheadsncam

iTrader: (26)

Ok, please excuse my lack of tuning knowledge. The turbo car I bought recently is being shipped today, and will be going from under 500 ft of elevation to around 3300 ft at it's final destination here in Texas. The car has a decent OLSD tune on it as it sits. My question is, since the oxygen content is different by a percentage vs. the elevation change, couldn't I just apply a set percentage globally to the ve table and get the fueling back to what it needs to be?

I know the motor will be running rich...any input will be appreciated.

Thanks!

eaglegoat

If the setup/tune is done correctly it should be just fine. It will only have problems if it's hacked. The myth of needing to "retune for altitude" comes from hacked tunes on cars with cheap parts.

98Zheadsncam

iTrader: (26)

So, because this is a speed density tune and the ecm is relying heavily on the map sensor, the tune won't change that much because air density is relative to pressure?

MontecarloDrag

iTrader: (3)

Oxygen content does not change by elevation. Atmospheric pressure is what changes, so the air is less dense but contains the same oxygen content %
If the tune was done correctly it will reference the new MAP reading and adjust fueling and timing accordingly.

98Zheadsncam

iTrader: (26)

Cool. He spent a good amount of time on the V.E. table street tuning the car, so I'm crossing my fingers.

Thanks for the input.

redtan

iTrader: (5)

Well because it's relying so much on the MAP sensor is why it's going to be ok going to different elevations as others have mentioned. Your engine will see less manifold pressure at higher elevations for the same type of driving, and the PCM will see that and with a proper tune should be just fine.

98Zheadsncam

iTrader: (26)

Well, this makes me feel a lot better. I really wasn't looking forward to paying $700-$800 for a 3 bar sd tune.

98Zheadsncam

iTrader: (26)

Well, I finally got the car Saturday night. I drove it around a bit yesterday, and the only issue I really see is the car surges at idle, in gear. In park it idles fine. Did a few WOT runs at 14psi and it feels really, really strong. LOL. Anyway, just thought I would update this. I'm taking it over to a tuner buddy today who also has a dyno, so I'll see what he can do.


Thanks again for the input, fellas.