Mass airflow sensors.

[Andrew Brownsword]

>> The other possibility is to install a MAF.  Unfortunately I know almost
>> nothing about MAF's and their output characteristics, and that is why I'm
>> writing to the list...
>
>Two very different types of GM MAFs, voltage output or frquency.  Rated by
>grams per second.  You'd need to match applications for getting one about
>the same flow range as what you need.


I need a voltage output in the range 0..5v.  The car's flow rate limit is
about 360 cfm at my target boost level (I think... I don't have my tables in
front of me, and its been a bad day), so a device that read 5v @ 400 cfm
should give enough of a buffer zone.


>> If I use a MAF, should I just ignore the IAT input?
>??.   MAFs measure Mass Air Flow, which automatically means it, compensates
>for temp..


Thats what my thinking is... but I don't know much about MAF's so I don't
know if a bit more compensation might be required?  The ECU in its original
condition uses the VAF, IAT and Baro readings to calculate airmass.


> What kind of MAF should I use, and where should I get it from?
>
>You have to figure what you need before you need to find where to get it.


Good point, but what are my options?


>  What are their output voltage curves
>> like?  What kind of processing should I do on the value from the MAF, or
>can
>> I just convert it straight into the internal airmass representation?
>
>One of the Ford guys had some flow bench numbers at the ford ecu list, no I
>don't have a URL.


Pity... does anyone else out there have flow bench numbers of this sort, or
the URL to this page?  Search engines these days don't seem to be worth a
hill of beans -- I've been trying all sorts of different searches with no
luck.  But then it has been a bad day.


>  What level of boost can a MAF sense? (my car has an aftermarket turbo,
which is
>> the whole reason for doing this).
>
>MAFs don't care about boost just how much air is flowing thru em.  The
trick
>is getting the fuel calibration right.

No doubt -- but I've got a Techtom and a dyno for this.

>Might try reading some more in the archives, about MAFs MAPs etc


Good idea, thanks.

  Andrew





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