FW: MAF Upgrad

[Joe Boucher]

No, the idea Mr. Mathews and I had (it's nice to know other  people are as deranged
as yourself!) was to mount the MAF sensor INSIDE a larger tube.  Don't touch the
original housing.  Just let the air flow through and around the original housing.
My first assumption was the MAF ECU's used look up tables like the MAF computers.
If this isn't so, then the changing of the eprom data maybe more difficult than a
MAP ECU.

Fluid mechanics was my weakest subject.  Part of the reason was nothing about
compressible flow is linear if the flow and pressure ranges are very wide.  In other
words I haven't a clue about the linearity of the flow vs. the MAF area.  Part of
the problem is the percentage of the air flow through or around the MAF could change
from idle to full throttle.  It would be a fun problem to figure out.

Joe Boucher
'70 RS/SS Camaro  '81 TBI Suburban

lkurek at smtpgate.anl.gov wrote:

>      The GM MAF is a Bosch unit.
>
>      So, you say I can cut away the 3" tube and replace it with a 4" one,
>      which would result in a 78% increase in flow area and compensate with
>      an increase in fuel pressure and/or injector size, in order to use the
>      same fuel map in the ECM? (I know...I could get a programmable unit,
>      but hey...I'm trying to be creative here :) ).
>
>      So, assuming my current fuel map was set with 22lb/hr injectors
>      @43psi, I could bump my fuel pressure to 76psi (please bare with
>      me...I know I could get into an injector lock problem here), or go to
>      40lb injectors (or a combination of both), and this would correlate
>      with the decreased MAF input to the ECM?
>
>      Anything else? What about low speed resolution? What about setting a
>      code for inadequate GPS flow at a given RPM? How linear is the flow
>      rate to MAF area?
>
>      TTYL!
>
>      Larry
>