Ported MAF. Does it help or hurt?
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Since the wire section can be separated from the aluminum guard, that section can be set aside in a safe place before you start whackin' away at the aluminum. I didn't touch any part of the wire section.
My SOTP dyno isn't calibrated fine enough to tell if there's any REAL hp increase, but since it can't help but pass a bit more air I can't see how it can hurt. The stock computer has been able to cope.
While the stock MAF may be "good up to 500hp", it begins restricting way before that.
I'm not sure why people will say not to mess with it. As long as you're careful with the wires there shouldn't be any issues.
And, I have just one thing to say to those that believe Mother GM can do no wrong and everything that comes out of her womb is infallible... Baloney.
They have, indeed, come up with some mighty fine ideas. But they are first and foremost a company that must make profits. Everything they do has to go past the bean counters, the pollution pukes, the durability testers, and the safety weenies before it gets the nod. NOTHING is the absolute best that can be put on a car. "Is this the best we can do for the money we want to spend and make the most we can get?" might easily be their motto.
$.02
If you are running rich, get a tune, a MAF translator or HPP3. Once ported, the MAF is permanently f**ked.
Porting the MAF allows more air to pass for a given resistance reading. All it does is fool the PCM into thinking there is less air than actual is present. That was helpful in the days before LS1Edit since headers tended to make the cars run rich. Now, there is no reason to do that since tuning software is available.
A bigger 85mm MAF makes sense when combined with a 90mm intake (and a 85mm lid if you can find one). That eliminates the 75mm MAF from being a restriction.
As for the computer, I'm no whiz and don't have a tune. But, please humor me...
As I understand it, the computer can add and take away amounts of values in it's tables to adapt to variances that occur due to changes of octane, parts, weather, driver, etc. Thus, things we do to increase the amount of air flowing into the front side of the intake are compensated for up to the limit of the variables in the tables.
The question, then, would be (assuming no tune is applied): Wouldn't any changes to the intake be compensated for up to the limit of the stock tables, and wouldn't a car NOT "run lean" while within those tables.
Question Two would then be: Assuming the first question is true, at what point do the stock tables run out of variance? Will things as minimal as a K&N filter along with a ported TB and MAF take the intake charge past where the stock tables can compensate? Add a catback? Headers?
Or, to the tables run out quickly and minor mods take the tables past where they can help us?
I haven't looked at all the interactions, but you'll find that a car with wide LTRIM variances will get worse mpg and feel more sluggish than a car tuned with LTRIMs down in the 0 - 5% range. Lid and catbacks don't have too big a change (10 HP on 300 is only 3%) which is why small bolt-ons don't cause much tuning grief whereas a cam can cause wide swings (negative at low rpm and positive at higher rpm).
Hopefully, this has given you some insight. For more info, take a look in the PCM forum.



