Brent94Z

I've got two aftermarket plastic MAFs without screens. Both have what appear to be the same electronics "arrangement" as the stocker. What I mean is when looking at the Granatelli and then looking at the stocker, it is impossible to tell the Granatelli unit is "calibrated" because it looks identical to the stock sensor. If the design of the sensor at least looked a little different I'd be more inclined to agree with you about this but since they appear physically identical, I'm not so sure

94ta383

Mir Hussain says:In result you get Lower MPG, Rich Mix, little Less power, Dirty tips, and upset PCM


I concur. Regrdless of how unpopular a name he has. Anyone wanna trade a stock set of ends for my ported/descreened ends?

Mir Hussain

I have Ported MAF but with Screen
I know my its Kinda make you go

Janny

IF the PCM is seeing less air, would it not send in less fuel, making a leaner condition?

Dan K

Yes. That is why some say they gained horsepower by porting/descreening. They are allowing in "unmetered" air, therefore making the mixture leaner.
The pcm will correct for this at part throttle, but I'm pretty sure it can't at wot.

Mir Hussain

No no
MAF see MORE air, because un channel air.
Then O2 comes out let PCM know; Hey man you running RICH. PCM o ok. Lets cut back some fuel.
Then MAF said What ever O2 saying I dont care. Here is more air so mix it up with more fuel.
in result Richer trim.
Get it ?

Mir Hussain

Wrong!
Your PE tables comes from your regular registars (Aka LT trims followed by St tirms)

anaik

I'm wondering why no one has made a comment on my post of gaining 17 g/s. that is equivalent to 18 hp at the wheels. Actually it is between 15 and 17 g/s. If I put the screen back in, I lose the same amount. I've done this back and forth a few times to eliminate a possible error on my Scanmaster.
As O'Reilly would say, what say you.

FireAm94

A ported MAF will LEAN you not make you run richer. Sorry but you're mistaken.

Joe

Dan K

Let me try to understand what you just said.

How is the MAF sensor seeing MORE air when you said it yourself it is unchanneled/unmetered? That means the extra air that is sneaking through gives you more parts of air per the same amount of fuel.

I don't think so. You said yourself that it is unmetered air. The maf isn't "measuring" correctly because of the porting.

No, I guess I don't.

What? What did you just try to say. I'm not following you at all.
Besides, isn't this where a blm lock comes into play. If you use a blm lock than you have repeatable fueling at wot. O2 input is not used at wot anyways. The computer uses the PE tables...and as long as the blm is locked @ 128...they shouldn't have any effect on your PE. That is the whole point of the lock, isn't it...repeatability? Now I'm off somewhere else...

Maybe I'm wrong on some of the little details...but I'm pretty sure I've got the right idea here.
If you guys want to port and descreen and stuff go ahead...better yet, trade your stock stuff to someone who doesn't want their ported stuff since their car runs poorly with it.

Dan K

And you don't?

brokenz

Another vote yes. But keep your stock ends just in case. I'm using Whisper ported end that I got on sale from Thunder I think. No problems here.

Perry93TransAm

Yeah OK, I admit, her "chestal region" does sawy my vote (along with her posterior)

xxsaint69x

learn from others mistake..do not do it..the computer will REAdJUST AND BUMP UP YOUR BLMS canceling any gains u might notice...the only way to gain anything thru the MAF is thru changing MAF tables with Lt1_Edit

ba96ta

Performance ones are calibrated for no screen from the manufacture