[s-cars] MAF screen removal-please explain

[QSHIPQ at aol.com]

I understand it that a venturi (and hot wire MAF) takes a sampling of the total mass of the air entering the tube.  As such, it calculates total input based on a percentage of airflow thru a tube, in which case, it needs to be the least turbulent.  Which is why (according to Bosch) you want to screen the MAF, to get as close to laminar airflow as possible.  This prevents "tumbling" (correct terminology IMS)of air, causing mismeasures of air mass.  The tumbling effect changes based on airflow, so depending on how the MAF is designed, it can be more accurate at low flow, or more accurate at high flow.  IME, messing with MAF screens tends to mess up very low flow (rpm/boost) in the urs car.  The theory explained to me and on the various sites, tends to support the thinking.  I'm happy to stand corrected, or properly tuned as it were.

I believe you can go thru audifans.com homepage to access archives, but I don't know if the S-carlist archives can be found there or not.

SJ



In a message dated 4/19/2003 8:53:17 AM Eastern Standard Time, strangconst at rogers.com writes:

> I understand it that a venturi, modifies the air pressure based on it's flow.
> I didn't understand it that it modified the MASS of anything, though by increasing the pressure do you also increase it's mass due to the fact you have more mols in a given space ? If so, then I suppose the venturi would modify the mass of the air. While I have not opened my MAF, yet, I suspect it does not have a huge venturi effect. I may be wrong, in which
> case I will stand corrected.
>
> You have a URL for the archives ?
>
> Mark