Mas Air Flow
#1
07-05-2007 | 12:35 AM
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Professional
Joined: Jun 2007
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From: Chattanooga
Mas Air Flow
So ive jstu been looking around for any thing that will give me some extra horses.I know what mas air flow sensors are, and what they do.I was just wondering if anyone hasone and what differences it makes. I have not heard any real world info on them, only the stufffrom the site that really isnt allways trustworthy.
#2
07-05-2007 | 06:27 AM
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Joined: Aug 2005
Posts: 3,313
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RE: Mas Air Flow
http://tinyurl.com/2nzalx
not worth doing
unless you are 'going whole hog'
with an aftermarket EFI system
like F.A.S.T., Haltech, Motec or Electromotive
#3
07-06-2007 | 12:34 AM
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Joined: Aug 2005
Posts: 145
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RE: Mas Air Flow
Only, I can't seem to find any mention of MAF in the service manuals. Nor can I find anything, anywhere, on the intake stream that resembles a MAF sensor. I've serviced them on my Toyota Highlander and Pontiac Firebird. But, can't find them on my Dodge 3.8L v6, Chrysler 2.4L v6, or Dodge Hemi 5.7L v8. Makes me think that DC doesn't use MAFs.
#6
07-07-2007 | 10:16 AM
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Joined: Sep 2006
Posts: 582
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From: tx
RE: Mas Air Flow
they are speed density not MAF
This topic came from another post regarding a new cold air intake installed and possible loss of power. I had a similar problem when I installed my k&n fipk intake. Loss of power down low and no increase up top. Now heres the discussion.
Our hemi engines use speed density to measure air intake instead of air mass. I did some further research and found that speed/density is an openloop system which infers what the engine reqires from throttle position and vacuum with the actual fuel delivery based on preset mixture maps. And if the engine is modified, the mixture maps must be revised accordingly.
Mass airflow systems measure what the engine requires using the air mass being injested and supply the fuel required to give the right mixture at that time while closing the control loop by sensing the oxygen content in the exhaust. Mass airflow systems adapt to the actual engine combustion conditions.
So it seems to me that with our system, we need to change the preset mixture maps after we make any modifications to the engine. This is what I found on some research I did. If anyone has any input, please give it. Thanks.
Our hemi engines use speed density to measure air intake instead of air mass. I did some further research and found that speed/density is an openloop system which infers what the engine reqires from throttle position and vacuum with the actual fuel delivery based on preset mixture maps. And if the engine is modified, the mixture maps must be revised accordingly.
Mass airflow systems measure what the engine requires using the air mass being injested and supply the fuel required to give the right mixture at that time while closing the control loop by sensing the oxygen content in the exhaust. Mass airflow systems adapt to the actual engine combustion conditions.
So it seems to me that with our system, we need to change the preset mixture maps after we make any modifications to the engine. This is what I found on some research I did. If anyone has any input, please give it. Thanks.