View Poll Results: Port & Descreen MAF with spray?
Yes! do the free mod!
38
56.72%
No! It's too dangerous
29
43.28%
Voters: 67. You may not vote on this poll
To Port & Descreen or not to port & descreen?
07-12-2006, 08:58 PM
#1
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To Port & Descreen or not to port & descreen? That is the question. What kind of advantages/disadvantages can be seen with a ported/descreened MAF with a dry kit spraying before the MAF; i.e. intake lid? Is a tune necessary after this?
07-13-2006, 05:47 PM
#7
I was getting "pinging" on N/A with the "ported MAF" ends. Went back to the stock MAF "screened" ends, and it went away. I noticed a drop in power with the stock unit as well. 100 shot dry here, TR-6 plugs. I don't know if it has something to do with the stock tuning I am on or what.
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09-21-2006, 03:59 PM
#13
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i question for the descreen?
i have a functional ram air hood and FRA mod, and when i clean out my filter i see some small debris that is held back by the screen. if this small amount of debris enters the maf, will it damage anything?
i have a functional ram air hood and FRA mod, and when i clean out my filter i see some small debris that is held back by the screen. if this small amount of debris enters the maf, will it damage anything?
09-21-2006, 10:27 PM
#14
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Sounds to me like you need to recharge your filter or get a new filter. because in order for debris to pass thru the MAF it has to go thru the filter first.
09-22-2006, 05:57 AM
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Excellent question! I would like a technical explanation as well, and "it throws off the tune" doesn't cut it. Too many people have the ability to tune their cars nowadays for that to fly. There are also plenty of other cars that come from the factory without fins built into the MAF, like those wicked fast Toyotas.
OK, so they're not that fast but they still work.
OK, so they're not that fast but they still work.
09-22-2006, 09:51 AM
#17
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You have to look at how the MAF works.
It doesn't sit there and count every gas molecule. It
samples the air that passes close enough to the sense
resistor elements, to affect them thermally. To relate
that to total airflow an empirical relation was determined,
and embedded to the electronics calibration (full scale
at full flow) and the tune data (stepwise air per freq).
So fundamental to the calibration is this relation of the
sampled air to the total air, which is directly the area of
the throat and the distribution of the airflow across that
area.
Every time either of these deviate from stock, so does
the airflow reading vs airflow actual.
Porting increases the actual area and actual airflow for
a given reported airflow (as frequency).
Descreening increases the chance of airflow being
biased across the face of the MAF. The screen is not
there for bugs, it's really a drag channel plate which
forces a more even distribution across the face at the
cost of some pressure drop (no pressure gradient, no
air redistribution). If the incoming air is straight and
nonturbulent, the screen is a worthless restriction.
If your inlet tract is curved then it does a job. Truck
and 'vette guys see more tune drift from descreening
than F-body because they have bent pipe inches
before the MAF and centrifugal airflow bias around
that bend is not fully settled before it passes the
MAF.
The airflow bias from descreening is less of a skew
than the porting. I once modified a SLP MAF to take
the resistor outboard and adjustable. I dressed this
MAF lightly with a file, just to deburr the zinc ring
to plastic step. This produced maybe 10% drift in
output (by the LTFTs) and needed a 20% change in
resistor value to bring back to original. This wasn't
even significant material removal.
So descreen but be ready; port and you'll never be
ready. Unless you have a flow bench, a reference
MAF and some frequency meters.
It doesn't sit there and count every gas molecule. It
samples the air that passes close enough to the sense
resistor elements, to affect them thermally. To relate
that to total airflow an empirical relation was determined,
and embedded to the electronics calibration (full scale
at full flow) and the tune data (stepwise air per freq).
So fundamental to the calibration is this relation of the
sampled air to the total air, which is directly the area of
the throat and the distribution of the airflow across that
area.
Every time either of these deviate from stock, so does
the airflow reading vs airflow actual.
Porting increases the actual area and actual airflow for
a given reported airflow (as frequency).
Descreening increases the chance of airflow being
biased across the face of the MAF. The screen is not
there for bugs, it's really a drag channel plate which
forces a more even distribution across the face at the
cost of some pressure drop (no pressure gradient, no
air redistribution). If the incoming air is straight and
nonturbulent, the screen is a worthless restriction.
If your inlet tract is curved then it does a job. Truck
and 'vette guys see more tune drift from descreening
than F-body because they have bent pipe inches
before the MAF and centrifugal airflow bias around
that bend is not fully settled before it passes the
MAF.
The airflow bias from descreening is less of a skew
than the porting. I once modified a SLP MAF to take
the resistor outboard and adjustable. I dressed this
MAF lightly with a file, just to deburr the zinc ring
to plastic step. This produced maybe 10% drift in
output (by the LTFTs) and needed a 20% change in
resistor value to bring back to original. This wasn't
even significant material removal.
So descreen but be ready; port and you'll never be
ready. Unless you have a flow bench, a reference
MAF and some frequency meters.
09-27-2006, 04:18 PM
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Originally Posted by shkettle
yeah i need maf ends as well
You guys have the right idea if your not up to purchasing a high-flow MAF. We have MAF housings which is not only ported & descreened, but billet aluminum for one sexy maf.
Give us a call if you're interested.