MAF Question? Possible HP gain?? - Pontiac G8 Forum: G8 Forums - G8Board.com
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post #1 of 22 (permalink) Old 04-17-2008, 04:32 PM Thread Starter
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MAF Question? Possible HP gain??

hey guys.

I have been told that if you take that mesh screen out in the MAF you get better flow and therefore more HP. The theory is sound but will it mess comp codes up??

Thanks guys.

When i put my CAI on a couple of days ago I noticed that the screen is in there pretty good and would not be easy to pull. My local speed shop can port the MAF and TB. I would assume they will do it then anyway... so... ??

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post #2 of 22 (permalink) Old 04-17-2008, 04:37 PM
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That screen is there to smooth the airflow so that the Mass AIRFLOW Sensor can do its job correctly. Removing the screen will screw up the signals that it sends to the computer which will then screw up the amount of fuel thru the injectors.


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post #3 of 22 (permalink) Old 04-18-2008, 04:08 AM
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That screen is there to smooth the airflow so that the Mass AIRFLOW Sensor can do its job correctly. Removing the screen will screw up the signals that it sends to the computer which will then screw up the amount of fuel thru the injectors.
that is PROBABLY true, but do you have any data to back that information up from another G8?


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post #4 of 22 (permalink) Old 04-18-2008, 07:47 AM
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Leave the screen in

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post #5 of 22 (permalink) Old 04-18-2008, 07:59 AM
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The screen is there to make sure the sensors in the MAF see a true picture of the average condition of the incoming air. If you remove the screen you MIGHT, see a very small increase in max flow, the MAF and screen are typically not the main restriction in the intake system. The trade-off for a pretty meaningless gain at high flow rates is poor measurement at low flow rates and difficulties metering correctly at idle and low speed operation.

Not worth it. Leave the screen intact. There is no free lunch.


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post #6 of 22 (permalink) Old 04-18-2008, 09:37 AM
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Basically the others summed it up, the screen helps smooth out and evenly distribute the airflow across the MAF wire which helps it achieve more accurate readings.

BUT, just about every modded f-body and Corvette on the road probably has their MAF descreened and has not had any issues with it. I personally have not seen any difference in MAF reading having the screen on vs. having it off.

Unless you are spraying a dry shot I don't see any reason to take it out at this point.




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post #7 of 22 (permalink) Old 04-18-2008, 10:41 AM
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The screen is there to make sure the sensors in the MAF see a true picture of the average condition of the incoming air. If you remove the screen you MIGHT, see a very small increase in max flow, the MAF and screen are typically not the main restriction in the intake system. The trade-off for a pretty meaningless gain at high flow rates is poor measurement at low flow rates and difficulties metering correctly at idle and low speed operation.

Not worth it. Leave the screen intact. There is no free lunch.
do you have data to back what your saying? On all my friends f-body's and b-bodies they all have ran a descreened MAF with zero issues.

Personally, I don't know if I would do it because a car like mine has a very sensitive MAF. Just a CAI or adding tubing from the fog light area to the air fliter can make it start stalling. But im not going to sit here and pretend to say descreening a MAF will affect a G8 negatively as fact when there is ZERO proof/data out there to back up that statement. Nobody can even comment on the flowrates/horsepower gains at this point either.


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post #8 of 22 (permalink) Old 04-18-2008, 11:11 AM
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There are number of guys with grand prixs that removed the screen to gain more flow at WOT. Some of them experienced poor idle performance and slight off-stumbles. The guys with power Tuners and HP Tuners could fiddle with the MAF table in this area and make it better. Others didn't care and just lived with it. I found on my '04 GTP that the very small increase in max flow and the very small HP gain were easily overshadowed by other changes and, in my mind, not worth the hassle.

I'm an engineer and we use MAFs in several non-automotive related products. If you screw with the flow pattern of the air moving across the element, you will go through flow rates that are pretty close and other that are not. It makes getting accurate measurements across the intended flow range pretty difficult if not impossible.


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post #9 of 22 (permalink) Old 04-18-2008, 01:05 PM
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Originally Posted by TrickStang37 View Post
do you have data to back what your saying? On all my friends f-body's and b-bodies they all have ran a descreened MAF with zero issues.
I know on the B-body's most of the guys strongly recommend against doing it. I assume the F-body's are the same. They say it's harder to tune it to be consistent without the screen I believe.

The new Corvette (Z06?) doesn't have a MAF screen. What I heard the story is with that is because the filter is inline with the MAF, and the distance is so short the air doesn't need the screen. But, wherever I read that may be wrong.
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post #10 of 22 (permalink) Old 04-18-2008, 03:28 PM
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Z06's haven't had MAF screens since 2001.




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post #11 of 22 (permalink) Old 04-18-2008, 08:46 PM
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Its not going to hurt anything to take the screen out of the maf.You will not see a big increase in airflow but every bit helps mine was out of my G8 the second day I had it. It will lean the car out a bit I have seen that on a A/F meter.I have 4 cars with lsx based motors in them and not one of them has a screen in the maf.

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post #12 of 22 (permalink) Old 04-18-2008, 09:10 PM
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Originally Posted by U LUZ View Post
Its not going to hurt anything to take the screen out of the maf.You will not see a big increase in airflow but every bit helps mine was out of my G8 the second day I had it. It will lean the car out a bit I have seen that on a A/F meter.I have 4 cars with lsx based motors in them and not one of them has a screen in the maf.
you say it leans out the AFR right?

from what i have read that by putting a CAI on it richen's the AFR...

So by taking off the screen in the MAF help HP when having a CAI?

thanks
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post #13 of 22 (permalink) Old 04-19-2008, 09:13 AM
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I pulled the screen on my 2000 Z-71 and my LTRIMS (Long Term Fuel Trims) went up 2% showing me a richer mixture.

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post #14 of 22 (permalink) Old 04-19-2008, 02:46 PM
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I know on the B-body's most of the guys strongly recommend against doing it. I assume the F-body's are the same. They say it's harder to tune it to be consistent without the screen I believe.

The new Corvette (Z06?) doesn't have a MAF screen. What I heard the story is with that is because the filter is inline with the MAF, and the distance is so short the air doesn't need the screen. But, wherever I read that may be wrong.
The screen removes the turbulence in the air and makes the flow more even. Since air behaves like a fluid, in a pipe it will have a velocity profile like so:



Without the screen, in a pipe of a consistent diameter that bends, turbulent air can play with the sensor, giving incorrect air readings. The screen effectively turns the large diameter pipe into many, small diameter pipes, allowing consistent velocity and laminar flow, and assuring good readings.

As a side note, the air is kept non-turbulent through the intake manifold and heads by "trumpeting" the runners to accomodate for the variation in velocity across the width of the pipe.


So having no screen in the corvette is acceptable because of the straight flow to the MAF, as well as a very un-restrictive induction. On the G8, with it's curved pipes for packaging, and resonator sections in the pipe for noise, you will get more consistent performance by leaving the screen in.
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post #15 of 22 (permalink) Old 04-15-2010, 10:15 AM
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What about just changing the MASS AIRFLOW SENSOR to a aftermarket(high performance) one instead of taking out screen?...is that safer and wha bout HP gains?!?

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post #16 of 22 (permalink) Old 04-15-2010, 06:54 PM
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Originally Posted by vhato View Post
I pulled the screen on my 2000 Z-71 and my LTRIMS (Long Term Fuel Trims) went up 2% showing me a richer mixture.
FYI, an increase in your LTFTs (i.e. +2 instead of 0) means that you were actually running lean and the computer is commanding an additional 2% to bring it to stoich. To me that means you saw a leaner mixture rather than richer.

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post #17 of 22 (permalink) Old 04-15-2010, 09:23 PM
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FYI, an increase in your LTFTs (i.e. +2 instead of 0) means that you were actually running lean and the computer is commanding an additional 2% to bring it to stoich. To me that means you saw a leaner mixture rather than richer.

simple typo. thanks. But it was richer. Computer was constantly fighting to get it inline after I tuned it. It was richer.

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post #18 of 22 (permalink) Old 04-15-2010, 10:46 PM
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I had a JET maf sensor in my old G6 GXP. At wot I got a cel with 2 lean codes. Chris was my tuner at the time and told me to put the stock one back on and I did and never had problems. Now you might beable to get a tune specific for a maf, dont know. My dad put it on his stock 08 GP and didnt have any issues. Its been on there all winter. But he doesnt do wot runs.

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post #19 of 22 (permalink) Old 04-15-2010, 11:10 PM
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Sounds like a waste of time to take out a screen that is considered a part of the Factory Emissions system so it would or could have an affect if there is a problem while under warranty.Just my opnion. My trans Am is missing the screen and has always had a stumble when trying to speed up and it is a Ram Air factory car.
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post #20 of 22 (permalink) Old 04-16-2010, 03:02 PM
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Originally Posted by OUTASGHT View Post
What about just changing the MASS AIRFLOW SENSOR to a aftermarket(high performance) one instead of taking out screen?...is that safer and wha bout HP gains?!?
It's what you would call a "lateral" upgrade. I would do nothing for you other than run a bit richer, better upgrades to spend your money on for sure.

You can de-screen the MAF yourself with a screw driver since it is only a thin aluminum mesh. You may affect daily driveability, talking from exp. you will not notice any gains. I purchased a spare MAF on flea-bay, it was de-screened so I ran it. No difference one way or the other for me.

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