What have we all decided on the MAF screens? Since I'm running out of things to clean before getting the cam in on Monday, should I pull the screens?

 

Some say no, some say yes. Mine are out. I watched a stock LT4 pickup 5rwhp in back to back dyno runs swapping MAFs for one with screesn for one without.

 

Ooo! exactly what i was looking to hear. I tried to do this last time I dyno'ed my car. It was at a dyno day so we didn't have a bunch of time. I tried borrowing a friends MAF and accordion that didn't have screens in .. but when i swapped the damn thing wouldn't let my car start.. haha. So i didn't get to try it out.

5rwhp works for me! :cool:

 

I have had mine out for some time now. Don't have any data to document performance, but it hasn't caused any obvious problems. If you look it is an obvious flow restriction. If you are careful you can remove it without damaging it so you could always put it back. With your new cam a little more air can't hurt! Seems lots of performance MAF on market don't have the screen.

 

do a search. they are "air straightening screens" , not debris screens.
I talked about it before.

 

Have mine out..... no problems yet, :thumbs:

 

Sorta unnecessary on the Y-bodies though don't you think?

 

Don't LT1s and L98s have different kinds of screens? I don't see how the screen on my 89 would have straightend anything, it looked like the same stuff from a screen door, only bigger.

 

Not necessarily unnecessary. If you can follow that double negative, think about it; an analytical look at the air path in our cars tells that it is not a laminar flow of the intake stream from entry (@ filter) to the front of the MAF. The air comes in 'flat' through the flat narrow neck of the air cleaner base (designed as such by necessity for hood clearance) then enters the expanded oval part of the air cleaner base that connects to the air bridge 'snorkel', the rubber air bridge recieves it and funnels it into the round(er) part of the air bridge right before it hits the MAF. And the air bridge has that accordian pleated design as well.

Hardly a smooth ride for the intake charge. Smoother than the route the air takes in an F-body for instance, but still not a laminar flow.

In an LT1/LT4 the MAF screen's design is intended to help smooth out the somewhat turbulent air stream just before it encounters the metering wires/diodes of the MAF. Removing the screen on a stock MAF can only serve to throw it out of calibration somewhat.

Supposedly Granatelli compensates in their MAF's ROM code, i.e. calibration, for lack of a screen being present.

One dyno test on one car showing a 5 hp improvement is not enough to convince me that GM had it wrong when they designed the 92 - 96 MAF's (actually Delphi or someone else probably designed the MAF's to spec...). I hear the LS1 MAF's do not have screens. However they were designed that way from the beginning hence they are calibrated for it in the MAF's chip.

Just my $0.02 worth. I could be wrong.





[Modified by Lone Ranger, 10:33 PM 1/17/2004]

 

This is an example of much a single screen can straighten airflow.
http://ateam.lbl.gov/PUBS/cec/Append..._Fume_Hood.pdf

 

:cheers: Didn't know such a document was out there. :cheers:

 

All this, and the "Tornado" says that swirling it all around is the best :lol: . It must be true, cause they ran water through it and it made a whirlpool. I am just kidding and NO, I don't have one. I do have one question about this topic. I haven't taken off my MAF, but when I do, is the screen removed by disassembling the MAF? I can't imagine that people would cut it out.
Thanks.
Jim


[Modified by OneRedLT4, 11:49 PM 1/17/2004]

 

WOW .. excellent documentation. I wonder if the screen was put there to create waves of air specially for the engine like the pictures of smoke in that document....hmmmm

 

L98: Take it out
LT1/4: Leave it in

 

:sad: you are not going to be with us at Gainesville for Winter Jam 2

Are you going to make any part of Winter Jam?

You say remove the screen on l 98's, what's your reasoning? I am not disagreeing, just seeking knowledge

Thanks

Jack


:seeya

:steering:

 

What's winter Jam 2? Gainsville Texas?

 

Hmm.. still not sure if I'm going to take them out, lol. I may wait.... someone should flow test the stock MAF with and without the screens to see exactly how much difference they make.

 

I yanked mine out when I got my LT4, and didn't notice any difference in drivability.

 

:yesnod: :yesnod: :yesnod: I did it with my '85. :yesnod: :yesnod: :yesnod:

 

On the older maf's the screens are pretty restrictive, so removing them gives some gain. I picked up about a half a tenth consistently when i took them out at the track, making several before and after runs.

As far as the newer style ones, they really aren't a problem. I descreened it at the track with my LT1 T/A and picked up nothing.

Chris