descreened maf?? yes/no??
#3
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You'll mostly hear, "NOOOOOOOOOO!!!!!!" around here, but it's debatable.
In the how-to book, " How to Build High-Performance Chevy LS1/LS6 V8's" by Will Handzel (who was a program manager working on development of the LS1), it states uncategorically in Chapter 3 that it is OK to remove the MAF screen. In fact, he states, "The simple modification that should be performed to every MAF sensor is the gentle removal of the inside screen."
I quote, "The screen is used to straighten the coming into it to minimize false airflow readings, but on LS vehicles with straight intakes, the screen isn't required. On trucks, where the air tube aspproaches the MAF from teh side, the screen should be left in unless your willing to make calibration changes to account for the new readings."
So, listen the the naysayers and take your pick. I say go ahead and remove it.
In the how-to book, " How to Build High-Performance Chevy LS1/LS6 V8's" by Will Handzel (who was a program manager working on development of the LS1), it states uncategorically in Chapter 3 that it is OK to remove the MAF screen. In fact, he states, "The simple modification that should be performed to every MAF sensor is the gentle removal of the inside screen."
I quote, "The screen is used to straighten the coming into it to minimize false airflow readings, but on LS vehicles with straight intakes, the screen isn't required. On trucks, where the air tube aspproaches the MAF from teh side, the screen should be left in unless your willing to make calibration changes to account for the new readings."
So, listen the the naysayers and take your pick. I say go ahead and remove it.
#6
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Go ahead and jack with it. Port out your O2 sensors while you're at it.
PS - That was sarcasm. Descreening/porting the MAF *could* cause problems, we've all seen them before. The almost zero gains at the risk of problematic behavior is something you're going to have to mull over.
PS - That was sarcasm. Descreening/porting the MAF *could* cause problems, we've all seen them before. The almost zero gains at the risk of problematic behavior is something you're going to have to mull over.
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#8
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The LS1 book says it's a good thing to do with the LS1/LS2's because the air shoots through a straight pipe. On the truck's, no because the air curves around a corner.
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Originally Posted by 4mula
not all too long ago in my car the screen was holding a cigarette butt.
There is no way a ciggarette butt made in throw your air filter or you have problems.
The maf screen is not for filtration its to straighten the incoming air.
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I had a moth and two grasshopper legs in mine when I first saw it.
And yet, after all these years, and all the millions of miles driven by LSx's without MAF screens, who has a problem to report from something getting through there?
Foam, butts, moths...all from not paying attention or from prior owners not paying attention.
Performance gain? Pffft. You'll do better if you have a clean air filter. Your motor going to ingest small animals or children without it? Not if you ensure you have a filter properly seated and foam strips/mods properly placed.
And yet, after all these years, and all the millions of miles driven by LSx's without MAF screens, who has a problem to report from something getting through there?
Foam, butts, moths...all from not paying attention or from prior owners not paying attention.
Performance gain? Pffft. You'll do better if you have a clean air filter. Your motor going to ingest small animals or children without it? Not if you ensure you have a filter properly seated and foam strips/mods properly placed.
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Originally Posted by JerseyLS1TA
No. It's not worth the .0001 hp gain for something to possibly slip by your air filter and screw up the sensors in the MAF.
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Originally Posted by Justin00SS
Someone put out their cigarette and dropped the butt on the back of the airfilter then you put the lid on with this butt still in there.
There is no way a ciggarette butt made in throw your air filter or you have problems.
There is no way a ciggarette butt made in throw your air filter or you have problems.
i did it, but i would only suggeset doing it on a 6 speed car, automatics tend to have more problems without the screen than 6 speeds do. you might pick up a couple hp from it, so you've got to determine for yourself if a couple hp is worth it. i just figured that as long as the air filter was doing its job there wouldn't be a problem.
#18
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i've had my MAF screen out for over a year and no problems! port your MAF ends or buy ported and it increase airflow... but remember, you can only do so much b4 you have to get a ported or aftermarket TB b/c that's what allowing the air in the engine to begin with. good luck
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Record your MAP drop at the top end, WOT. If you are
less than 95% of your low-RPM MAP then you can bet
the screen is a big piece of it (equal to the stock lid
restriction, by my measurements, which were lower
flow so showing less than ultimate turbulent drag in
the "screen" channels; believe higher flows will show
worse for MAF pressure drop).
I don't think people who say "Pffft" have made such
measurements themselves. And having measured
MAF, lid and filter pressure-costs individually and
together, I have the data to say !Pffft.
posted June 11, 2002 07:47 PM
...
These are the pressure drops I recorded, in inches
of water:
Lid, no filter: 0 - same as open shop vac port
Lid, Donaldson: 1/2"
Lid, Purolator: 3/4"
Lid, Fram: 7/8"
Lid, OEM: 7/8"
By comparison:
OEM Lid, open: 1-1/8""
MAF with screen: 2"
I later measured the descreened truck MAF which
registered zero drop at my attainable airflow. A clean
paper filter is well less than half, maybe a quarter, of
the drop you get from the MAF "screen".
If you can't record the MAP reading then you're not
in a position to deal with any of the more subtle MAF
descreening effects. If you can't fix, don't hack.
In my case ill effects were none, descreened truck
MAF and truck table, perfect as far as mixture fidelity.
If your intake tract is not a pretty straight shot,
don't go there. Airflow bias and turbulence are the
reason for the channel-plate ("screen") so best not
to have any. You could try to deal with it in the MAF
model table but it may not be so consistent as you'd
like.
less than 95% of your low-RPM MAP then you can bet
the screen is a big piece of it (equal to the stock lid
restriction, by my measurements, which were lower
flow so showing less than ultimate turbulent drag in
the "screen" channels; believe higher flows will show
worse for MAF pressure drop).
I don't think people who say "Pffft" have made such
measurements themselves. And having measured
MAF, lid and filter pressure-costs individually and
together, I have the data to say !Pffft.
posted June 11, 2002 07:47 PM
...
These are the pressure drops I recorded, in inches
of water:
Lid, no filter: 0 - same as open shop vac port
Lid, Donaldson: 1/2"
Lid, Purolator: 3/4"
Lid, Fram: 7/8"
Lid, OEM: 7/8"
By comparison:
OEM Lid, open: 1-1/8""
MAF with screen: 2"
I later measured the descreened truck MAF which
registered zero drop at my attainable airflow. A clean
paper filter is well less than half, maybe a quarter, of
the drop you get from the MAF "screen".
If you can't record the MAP reading then you're not
in a position to deal with any of the more subtle MAF
descreening effects. If you can't fix, don't hack.
In my case ill effects were none, descreened truck
MAF and truck table, perfect as far as mixture fidelity.
If your intake tract is not a pretty straight shot,
don't go there. Airflow bias and turbulence are the
reason for the channel-plate ("screen") so best not
to have any. You could try to deal with it in the MAF
model table but it may not be so consistent as you'd
like.
Last edited by jimmyblue; 02-02-2007 at 09:25 AM.