3" GM MAF

[milenium99]

Not sure if this is the right forum for this but need some help.
Bought a 3" GM Maf off another dsmer but I'm looking at it and one I saw on another site and it's missing the metal screen. Do I need that and can I even use it???

THanks fo any Help
Junior

 

[DBR01]

no you don't really need it......as a free mod most people take this screen off for restriction purposes.....you'll be fine without it.....

 

[milenium99]

no you don't really need it......as a free mod most people take this screen off for restriction purposes.....you'll be fine without it.....

thanks

 

[blackGSX2g]

I bought mine without it and have no problems. Its just there to straighten out the air, but on a hotwire system, that isn't as important as our stock vortex type.

 

[psychlow]

I got this off of a GM-site awhile back. YMMV.

In front of the heated wire is a screen. Many people are suggesting that improved airflow will be gained by cutting the screen out of the MAF. It is not recommend that this be done on an F-body. Most people mistake this screens purpose as preventing debris from hitting the hot wires in the MAF (that is what the air filter is for). Actually the screen is a bank of straightening vanes used to straighten the airflow before passing by the hot wires. Eddies and vortices (turbulence) in the MAF will cause inaccurate readings. Straightening vanes are used in most mass flow measurement situations where 10 diameters of straight upstream conduit are not available. The F-body intake does not meet this requirement.

An accurate MAF sensor is critical for the engine's fuel/air ratio adjustments. So, what happens when the screen is removed? The flow (mass) is the same, BUT without the screen (which is a restriction) the velocity is lower. Lower velocity means a hotter wire temperature which equates to a LOWER flow! So the PCM adjusts the injectors to provide LESS fuel. Since the HO2 sensors do not provide input when the MAF is online the PCM does not adjust for the LEAN condition, until it goes back into Closed Loop Condition.

 

[mavisky]

I got this off of a GM-site awhile back. YMMV.

that's some good info right there.

 

[ITSME4G63]

so in other words, better to leave the screen on.

 

[DBR01]

so in other words, better to leave the screen on.

not if you have a 4G63T.....the MAS is right off of the filter.....the air doesn't have time to create turbulance.....psychlow pulled that off of a GM forum.....f-body's are camaros and firebirds and such which have long cold or cool air intake systems....this is not the case on dsm turbo cars.....

 

[blackGSX2g]

not if you have a 4G63T.....the MAS is right off of the filter.....the air doesn't have time to create turbulance.....psychlow pulled that off of a GM forum.....f-body's are camaros and firebirds and such which have long cold or cool air intake systems....this is not the case on dsm turbo cars.....

Yea, thats what I was thinking too. I can see what they are talking about when the air is being drawn in, but when there are 15 some odd psi blowin big CFM numbers past it, I don't see the screen as anything but a hinderance.

 

[psychlow]

not if you have a 4G63T.....the MAS is right off of the filter.....the air doesn't have time to create turbulance.....psychlow pulled that off of a GM forum.....f-body's are camaros and firebirds and such which have long cold or cool air intake systems....this is not the case on dsm turbo cars.....

I think maybe you misread it, or didn't read that we were talking about using a GM MAF on DSM's, or maybe didn't know that most DSM's with GM MAFs are blow-through, meaning it's in the upper intercooler pipe.

If you've looked at a Firebird or Camara LS1 intake, it is short and very accordian-like. This is bad because it creates turbulence and doesn't have enough room to flow in a straight pipe to meter air correctly without the screen.

Most DSM setups are the same thing. The requirement is 10 diameters of straight, upstream conduit. On a 3'' GM MAF sensor, that means you need 30 inches of smooth pipe with no bends in order for the screen to be unnecessary. Especially considering that the compressor wheel is going to create turbulence because of the way it works naturally, and also considering it's going through a small diameter, into large diameter (the intercooler), then back out to a small diameter, then through bent piping, you'll probably want the screen for the most accurate readings.

 

[beat90tsi]

but when there are 15 some odd psi blowin big CFM numbers past it, I don't see the screen as anything but a hinderance.

But your car operates in vac a large majority of the time, and the ECU sets fuel trim values while in closed loop. I say, keep the screen, Lingenfelter Vettes don't show removing that screen as an upgrade, so I'm sure it's not all that restrictive.

 

[MXD]

Not to jack the post, but where do you guys usually mount this GM MAF sensor? On the intercooler pipes before the manifold or in the factory location? And also, how is this sensor wired to use the DSM plug/wires? Is this the best MAF sensor to use?

 

[milenium99]

thanks for the replies, but then the next question would be could i use it (the maf)? The screens already off and I want to go with a blow thru with the maf in the uicp, will it work? Is anyone else running this setup???

 

[miteclgst]

MXD the usualy installation location is between the throttle body and BOV, this way you can vent your bov into the atmosphere without any ill effects. Also this location allows for a more accurate temp reading, this can help you, through the use of a logger, find out how efficient your intercooler is, and will also help the computer adjust it's temp compensation to the actual air temp the engine sees, not the under hood temp. The MAF requires a translator that converts the MAF's output to Hz so that the computer can understand it.

 

[psychlow]

thanks for the replies, but then the next question would be could i use it (the maf)? The screens already off and I want to go with a blow thru with the maf in the uicp, will it work? Is anyone else running this setup???

Yes, you can use it without a screen. It would just be more accurate with the screen.

 

[MXD]

MXD the usualy installation location is between the throttle body and BOV, this way you can vent your bov into the atmosphere without any ill effects. Also this location allows for a more accurate temp reading, this can help you, through the use of a logger, find out how efficient your intercooler is, and will also help the computer adjust it's temp compensation to the actual air temp the engine sees, not the under hood temp. The MAF requires a translator that converts the MAF's output to Hz so that the computer can understand it.

Thanks for your response. Is the translator a software that has to be programed into a engine management system or is it some sort of physical part thats installed between the MAF and the factory connector?

 

[miteclgst]

It's a black box that connects b/w the factory plug and the GM MAF. They can be found on www.ramchargers.com. The black box also has adjustments that you can make to compensate for larger injectors, and other adjustments similiar to that of an AFC. if you are running stock injectors you will probably just select 450cc and zero everything else out.

 

[turboed420A]

Is this the one that you are suppose to get?


518TRANSPLUS $ 249.99 Air/Fuel and spark tuning computer for Turbo Buick and LT1

 

[miteclgst]

here is a link to the one I bought for my car. http://www.ramchargers.com/cgi-bin/...rfnbr=29889&cgmenbr=541&cat1=29839&cat2=29886

 

[blackGSX2g]

But your car operates in vac a large majority of the time, and the ECU sets fuel trim values while in closed loop. I say, keep the screen, Lingenfelter Vettes don't show removing that screen as an upgrade, so I'm sure it's not all that restrictive.

Haha, my car doesn't operate at all at the moment. I do see what you mean, but mine didn't even come with it so I didn't worry about it. It ran fine, I'm not about to go searching for the honeycomb stuff, but it is somethin to think about I guess.

 

[ekanddsm]

I guess the true test of the screen would be to dyno the car and then remove/install the screen and redyno the car. I agree the screen is a restriction, but accurate air flow reading is crucial to fuel management, I have seen air turbulence passed maf sensors(On Fords, And Mazdas) cause slight misfires, (Lower Injector Pulse Width) on just one cylinder, and all it felt like in the car was lower than normal power.
I worked with a engineer on this vehicle from mazda and it ended up being a incorrect air filter, being distorted in the housing caused the air flow to go just to one side of the maf sensor. 1G till I die

 

[ekanddsm]

By the way the Air Filter was from Autozone

 

[Scrymerr]

Most of you must have done every free mod known to man to need to move such a restriction from your intake system.

To the guy that bought it without the screen: dont worry.

To the rest of you: can it hurt to leave it in there?

 

[psychlow]

Most of you must have done every free mod known to man to need to move such a restriction from your intake system.

Seriously. The guys that take out MAF screens on LS1s are the same guys that have IAT resistors, honeycombs removed, and BCS mods in the DSM world.

Your MAF is 3 fricken inches wide. You don't need to remove a small screen for better performance.