MAF Screen Removal
Intermediate
Joined: Mar 1999
Posts: 40
Likes: 0
From: Naples FL
Re: MAF Screen Removal (Cobra4B)
As I mentioned in an earlier post, 1997-1998 LS1's had a fuel/air mixture that was on the rich side.
I have seen a number of articles over the years that reported individuals and tunners such as Doug Rippie achieved a 5 to 7 rear wheel horsepower gain on 1997- 1998 LS1's by removing the MAF screen, because this change leaned out the fuel/air mixture to a more optimum ratio.
In 1999, GM leaned out the LS1 fuel/air ratio, and in 2001 GM increased the LS1 MAF diameter from 74mm to 85 mm. As a consequence, removing the MAF screen on 1999 and newer LS1's offers little if any power gains.
I have seen a number of articles over the years that reported individuals and tunners such as Doug Rippie achieved a 5 to 7 rear wheel horsepower gain on 1997- 1998 LS1's by removing the MAF screen, because this change leaned out the fuel/air mixture to a more optimum ratio.
In 1999, GM leaned out the LS1 fuel/air ratio, and in 2001 GM increased the LS1 MAF diameter from 74mm to 85 mm. As a consequence, removing the MAF screen on 1999 and newer LS1's offers little if any power gains.
Instructor
Joined: Sep 2003
Posts: 177
Likes: 0
From: GREELEY CO
Re: MAF Screen Removal (C5BTW)
Then how about designing a program to show how your idea works?? Then when your own program proves you wrong what are you gonna do? I know you think that because the engine is quote "sucking like crazy", air velocity will increase so much that even after the screen it won't decrease velocity and spread out.. ITS JUST A SCREEN!! IT WAS PUT THERE FOR EXTRA PROTECTION IN CASE SOMETHING GETS PAST THE AIR FILTER!! IF you have ever had an engine apart you would already know this. I have built to date four (4) custom turbocharged engines- not kits that i put together but totally fabricated. So I think that you should just stick to computers.
Burning Brakes
Joined: Mar 2003
Posts: 915
Likes: 1
From: UK
Re: MAF Screen Removal (98VETTEC5)
ITS JUST A SCREEN!! IT WAS PUT THERE FOR EXTRA PROTECTION IN CASE SOMETHING GETS PAST THE AIR FILTER!!
The MAF screen is an airflow straightener, not an air-filter failsafe device! Think about it, if you drove through a cloud of dust with no air filter, what protection do you think the MAF screen is gonna provide? None whatsoever! Before the days of fuel injection, did cars come with an extra filter in case you forgot to put the air filter in? Nope!
On the point of straightening the airflow, I believe it is still a good idea to retain the MAF screen. Airflow is turbulent by nature and the MAF screen helps even it out so each MAF wire 'sees' the same amount of air. Also, you'd probably be asking for trouble if you removed the screen and decided to install a Halltech Sidewinder (or similar) intake where the intake air has to turn a corner before it gets to the MAF.
Cheers,
Ian.
:cheers:
Burning Brakes
Joined: Feb 2003
Posts: 871
Likes: 0
Re: MAF Screen Removal (98VETTEC5)
Now you had to get personal about it. But it's ok I know I'm right! :D
Burning Brakes
Joined: Feb 2003
Posts: 871
Likes: 0
Re: MAF Screen Removal (98VETTEC5)
Then how about designing a program to show how your idea works?? Then when your own program proves you wrong what are you gonna do? I know you think that because the engine is quote "sucking like crazy", air velocity will increase so much that even after the screen it won't decrease velocity and spread out.. ITS JUST A SCREEN!! IT WAS PUT THERE FOR EXTRA PROTECTION IN CASE SOMETHING GETS PAST THE AIR FILTER!! IF you have ever had an engine apart you would already know this. I have built to date four (4) custom turbocharged engines- not kits that i put together but totally fabricated. So I think that you should just stick to computers.
Advanced
Joined: Sep 2003
Posts: 53
Likes: 0
From: Norcross, Ga
Re: MAF Screen Removal (98VETTEC5)
I repeat you should read this article. http://www.vetteguru.com/mods/howto/#effects :banghead:
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Instructor
Joined: Sep 2003
Posts: 177
Likes: 0
From: GREELEY CO
Re: MAF Screen Removal (57xray)
I did, looks like we were both right on somethings and wrong on others. It says "First by removing the screen, you increase airflow. The PCM may need to be recalibrated to accommodate this new flow." MAY is the key word here. Maybe on 97-00 it's a good thing and on others it is not. But this thread is getting tired so farewell
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Blah, blah, blah 
.
The screens are on the lsx motors (with the exception of the '02+ LS6) becuase of their use in the pickup trucks. The trucks don't have a straight intake path and need the screens to create laminar airflow (straighten it out) so the MAF car accurately read the airflow. The Corvette has a strainght intake path and has NO need for the screen. The problem is that you have to tune the car to run correctly. Since a screen-less MAF is flowing more air now the MAF calibrations will be off and the PCM is "seeing" less air than is actually flowing. Thus, the car can run lean. Now if you're getting a tune then rip that sucker out.
. The screens are on the lsx motors (with the exception of the '02+ LS6) becuase of their use in the pickup trucks. The trucks don't have a straight intake path and need the screens to create laminar airflow (straighten it out) so the MAF car accurately read the airflow. The Corvette has a strainght intake path and has NO need for the screen. The problem is that you have to tune the car to run correctly. Since a screen-less MAF is flowing more air now the MAF calibrations will be off and the PCM is "seeing" less air than is actually flowing. Thus, the car can run lean. Now if you're getting a tune then rip that sucker out.
Will Handzel(Engineering GM Department head) wrote that using a screen in all vehicles early on was only to straighten air flow out since all vehicles used a crooked intake path(except Vettes) He states that you should remove it since all Vettes after 2002 didn't have them. That totally comes from the horses mouth and should end all controversy....maybe.
Pro
Joined: Nov 2005
Posts: 626
Likes: 0
From: Fresno CA
I remember Halltech actually recommends adding a screen when you install their CAI on 2002 to 2004 Z06. This was designed to eliminate the lean code issues and air turbulance when using their high flow CAI. Check out the Halltech web site for more info. The MAF screen is a keeper for me.
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
Quote:
Don't do it unless you plan on geting an LS1Edit tune to recalibrate the MAF tables.
You will lose hp and torque because the air velocity passing the MAF wires is what is important, NOT volume. The PCM tables are built with the MAF screen installed and will return less agresive numbers for spark advance and A/F mixture without it.
Well, that's one point of view, On the other hand...When I frst got my Y2K, I modded it with ported MAF ends, (no screen), a Vortex, and a 160 thermostat, and it ran considerably better than stock, I gained 4 MPH at the strip. It ran just like stock at low throttle openings.
It is the correct point of view. The idle will be a bit rough removing the screen as well. The 1-2 hp gain is not really worth the headache with out a tune.
Don't do it unless you plan on geting an LS1Edit tune to recalibrate the MAF tables.
You will lose hp and torque because the air velocity passing the MAF wires is what is important, NOT volume. The PCM tables are built with the MAF screen installed and will return less agresive numbers for spark advance and A/F mixture without it.Well, that's one point of view, On the other hand...When I frst got my Y2K, I modded it with ported MAF ends, (no screen), a Vortex, and a 160 thermostat, and it ran considerably better than stock, I gained 4 MPH at the strip. It ran just like stock at low throttle openings.
Well, that's one point of view, On the other hand...When I frst got my Y2K, I modded it with ported MAF ends, (no screen), a Vortex, and a 160 thermostat, and it ran considerably better than stock, I gained 4 MPH at the strip. It ran just like stock at low throttle openings.
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
Well, that's one point of view, On the other hand...When I frst got my Y2K, I modded it with ported MAF ends, (no screen), a Vortex, and a 160 thermostat, and it ran considerably better than stock, I gained 4 MPH at the strip. It ran just like stock at low throttle openings.
Bingo! You get it!
Will Handzel(Engineering GM Department head) wrote that using a screen in all vehicles early on was only to straighten air flow out since all vehicles used a crooked intake path(except Vettes) He states that you should remove it since all Vettes after 2002 didn't have them. That totally comes from the horses mouth and should end all controversy....maybe.
Will Handzel(Engineering GM Department head) wrote that using a screen in all vehicles early on was only to straighten air flow out since all vehicles used a crooked intake path(except Vettes) He states that you should remove it since all Vettes after 2002 didn't have them. That totally comes from the horses mouth and should end all controversy....maybe.
