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      01-25-2012, 02:44 AM   #588
Private First Class

Drives: e36, e46, e90 M3's
Join Date: Jan 2009
Location: Southern Florida

Posts: 199
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Losing sleep wrapping my head around this thought of a bad tune
I came to a stunning conclusion. Whereas this is just my thought, which will need to be confirmed by others, imagine this:
They tuned their kits for the atmosphere in Miami, which they claim is very harsh and if it can stand up to the high heat and humidity down there it should be fine everywhere else, correct?

"The addition of water vapor to air (making the air humid) reduces the density of the air, which may at first appear contrary to logic.

This occurs because the molecular mass of water (18 g/mol) is less than the molecular mass of dry air (around 29 g/mol). For any gas, at a given temperature and pressure, the number of molecules present is constant for a particular volume (see Avogadro's Law). So when water molecules (vapor) are added to a given volume of air, the dry air molecules must decrease by the same number, to keep the pressure or temperature from increasing. Hence the mass per unit volume of the gas (its density) decreases."

It is drastically more humid in Miami than in Raleigh. I was told their tune would work fine in my area. IF the humidity difference between the two area's is great enough the density of air would be too. This would result in more air getting into the combustion chamber than what was tuned for in Miami, resulting in a "lean" condition.

Perhaps they didn't take into account geographical differences when performing their R&D. Yes the tune may be safe down where the humidity is high, but is it elsewhere?

Now I can sleep.

Last edited by MPoweredAuto; 01-25-2012 at 03:01 AM.