Port/De-Screen Stock MAF?
08-20-2013, 07:54 PM
#1
Port/De-Screen Stock MAF? Just to clarify, I have an M6 car, so none of the A4 horror stories I hear. But is it worth it? I plan on getting a tune eventually, but after a few more mods (current mods in sig). Heard both sides of this story, and for now I'm thinking just to de-screen it. But with my mods and a stock tune, is porting it a bad idea?
08-20-2013, 08:51 PM
#3
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False. Stock MAF is as great a restriction as stock
lid, at airflows a shop-vac can pull - motor pulls
way more at the big end. I have measured that,
personally.
It's easy to remove the "screen" without damage if
you take off the front piece and soak it in paint stripper
overnight. Or you can get a junk LT1/LS1 MAF and use
that as an organ donor if you want to swap back and
forth, or keep that option.
lid, at airflows a shop-vac can pull - motor pulls
way more at the big end. I have measured that,
personally.
It's easy to remove the "screen" without damage if
you take off the front piece and soak it in paint stripper
overnight. Or you can get a junk LT1/LS1 MAF and use
that as an organ donor if you want to swap back and
forth, or keep that option.
08-20-2013, 09:34 PM
#4
Did some more digging and found that while it may not cause any problems for some people, the sensors are not reading the correct airflow (since they are not recalibrated) and thus relaying faulty info to the computer causing all sorts of problems. I think I'll wait until the day before I get a tune to port it along with my TB.
08-20-2013, 10:06 PM
#5
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I descreened my MAF on my old WS6 A4 and even before the tune didn't have any issues. Now I have a C5 with anodized ported MAF ends and no screen and still don't have an issue. Both cars have/had been tuned but ran fine before the tune as well.
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08-20-2013, 10:32 PM
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False. Stock MAF is as great a restriction as stock
lid, at airflows a shop-vac can pull - motor pulls
way more at the big end. I have measured that,
personally.
It's easy to remove the "screen" without damage if
you take off the front piece and soak it in paint stripper
overnight. Or you can get a junk LT1/LS1 MAF and use
that as an organ donor if you want to swap back and
forth, or keep that option.
lid, at airflows a shop-vac can pull - motor pulls
way more at the big end. I have measured that,
personally.
It's easy to remove the "screen" without damage if
you take off the front piece and soak it in paint stripper
overnight. Or you can get a junk LT1/LS1 MAF and use
that as an organ donor if you want to swap back and
forth, or keep that option.
08-20-2013, 10:39 PM
#9
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I also lightly ported my TB, did the free CAI mod, installed LT's, slp intake and full 3" exhaust so I wouldnt be able to tell you how much of a difference but i guarantee theres a slight difference.
look up all the free mods, every little bit helps.
look up all the free mods, every little bit helps.
08-21-2013, 10:22 AM
#11
It all boils down to who is tuning it and how. Geoff keeps a perfectly working stock screened MAF on hand in his shop just in case folks have messed with it. It's a LOT easier to tune for fuel injectors and whatnot bc you have a baseline to go off of with the stock MAF sensor.
Mine didn't become a restriction until my last round of tuning. It wasn't that the MAF couldn't keep up Hz wise, it was causing a restriction itself. 2 pulls and made 451/415. Also my KPA on the MAP sensor went from 100 down to about 97 at 4300 rpm.
Took the MAF off and set it for closed loop speed density, no tuning adjustments whatsoever, and put down 460/420, and my MAP still showed 100kpa all the way to where we set fuel cut to 6800.
Needless to say the MAF is still sitting in the backseat.
Mine didn't become a restriction until my last round of tuning. It wasn't that the MAF couldn't keep up Hz wise, it was causing a restriction itself. 2 pulls and made 451/415. Also my KPA on the MAP sensor went from 100 down to about 97 at 4300 rpm.
Took the MAF off and set it for closed loop speed density, no tuning adjustments whatsoever, and put down 460/420, and my MAP still showed 100kpa all the way to where we set fuel cut to 6800.
Needless to say the MAF is still sitting in the backseat.
08-21-2013, 12:57 PM
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Looking at where your MAP drops to, right before
shifts, is a good way to decide whether to mess.
Relative to the BARO number, (1-MAP/BARO)*350
is about how much peak HP you stand to gain by
relieving inlet tract restrictions (sum of lid, filter,
MAF and TB, with stock lid and stock screened
MAF being by far the most significant).
While this typically wants scanning / tuning software
to see, you could poor-boy it with a DMM on the
MAP signal and do the figuring later.
shifts, is a good way to decide whether to mess.
Relative to the BARO number, (1-MAP/BARO)*350
is about how much peak HP you stand to gain by
relieving inlet tract restrictions (sum of lid, filter,
MAF and TB, with stock lid and stock screened
MAF being by far the most significant).
While this typically wants scanning / tuning software
to see, you could poor-boy it with a DMM on the
MAP signal and do the figuring later.
08-22-2013, 08:26 AM
#14
I wouldn't be descreening the maf...it wouldn't be a restriction until a considerable level...the screen smooths the air...the benefit of descreening/porting is probably so low I'm not sure the reasoning of doing that, but everyone has their own way of thinking
08-22-2013, 08:44 AM
#15
I would replace the stock screen with a Saxon screen and leave the ends alone. http://www.saxonpc.com/100mm-cells-for-100.html
If you are getting the car tuned, buy a GM 85mm MAF before you do that if you can't leave well enough alone.
If you are getting the car tuned, buy a GM 85mm MAF before you do that if you can't leave well enough alone.
08-23-2013, 06:45 AM
#17
I would replace the stock screen with a Saxon screen and leave the ends alone. http://www.saxonpc.com/100mm-cells-for-100.html
If you are getting the car tuned, buy a GM 85mm MAF before you do that if you can't leave well enough alone.
If you are getting the car tuned, buy a GM 85mm MAF before you do that if you can't leave well enough alone.
