mvvette97

iTrader: (18)

I have heard both ways. For you that have done it , can you feel a differance?

corvet786c

iTrader: (6)

I bought a 2000 Trans Am with 55,000 miles and ported my MAF along with my other fbody cars. No problem at all, but you have to do it the right way which is to be very careful with the 3 small wires inside the MAF Ends. The computer will sence more air increase which will make it more leaner which is a litter more power.Along with airlid, and k/n filter some nice power. I hope this helps.

slow94GT

From what I hear, it's just a headache that isn't wanted.

mvvette97

iTrader: (18)

well In ported it and put it on and drove it to town. I can't really tell a differance. If anything I think it may of lost some power.

mvvette97

iTrader: (18)

I put my stock one back on so I will see if it gained or lost

Cld069

iTrader: (2)

Its 50/50 on this site. Im on the "dont do it" side. The stock MAF can handle up to 500 hp as it is, no need to mess with it. If your looking for power, go with bolt ons. It has been done successfully with no problems yea, but the payoff doesnt weigh out to the risk. That of course is just my opinion.

Torque_Wrench

iTrader: (13)

Hey bro, I also ported my MAF once....and I never felt a diffrence at all. To me it's a useless mod, not to mention a waste of time. The OEM MAF on your car is just about the best MAF you could have. GM spent alot of money and years designing that MAF and they have got it to the optimal performance design. So....hoped this helped in your answer quest.

orangeapeel

iTrader: (18)

there is no difference unless you can feel it pull +/-1 degree of timing.

Mr Incredible

I ported my MAF and I haven't had any detectable issues with it.

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

Ragtop 99

iTrader: (7)

Don't port the MAF. MAF porting is a ghetto method to lean the car's A/F.

If you are running rich, get a tune, a MAF translator or HPP3. Once ported, the MAF is permanently f**ked.

6-Speed Terror

iTrader: (4)

after porting mine it would lean out real bad when shifting and would cause a pull like when you wires are out. gona get a sd tune so that i dont have to worry about it anymore

mvvette97

iTrader: (18)

well i had some more unported housings so I put them back on. To me it seemed to run better without the porting

speed_demon24

iTrader: (6)

Just because it can handle 500hp doesn't mean it isn't a restriction below that power level.

lsx24

iTrader: (45)

If porting the tb gains hp/tq I don't see how porting the MAF wouldn't also, they are the exact same restriction.

Ragtop 99

iTrader: (7)

TB porting removes a ridge designed to help air flow at low rpm but slightly restricts flow at higher rpms at WOT. Expoxied TBs also improve the shape where the IAC motor is for better flow. There is no overall increase in diameter since the blade is 75mm and the throat is not ported. Therefore, the actual opening to the intake is not changed.

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.

Mr Incredible

I disagree. That the blade size is not changed is not relevant. TB porting does, in fact, remove a ridge right before the blade. That makes the opening wider than it was, thus making it bigger. That's why people do it. While they're at it, they smooth the hump out of the bell to ensure smooth transition of the airflow.

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?

DVS99TRANS

iTrader: (7)

Ported mine (LS1) and a buddy here (LT1) did his where I'm stationed, and we both got a lot better response. Nothing astronomical but something. Don't know if your car will go to the lean side instead of rich, it's just basicly a 50/50 shot. Good luck if you attempt it.

Ragtop 99

iTrader: (7)

The blade is that is where the minimum diameter of the TB is. That is the limiting factor. No matter how wide it is before the blade, that is the limiting factor. The stock MAF is 75mm. That's also why nobody reports consistent gains from aftermarket 85mm MAFs.

Eventually at part throttle it will learn out most of the impact through the LTRIMs. At WOT, that is not case. As long as the car is not lean (positive LTRIMs), I believe they are treated as zero at WOT. Therefore, a rich car can have a ported MAF lean the car out a bit and still gain at WOT. I don't think that the effect on the spark table is learned out, so you may permanently gain a few degrees of timing.

The LTRIMs can go +/- 25% so they have a big range. Unfortunately, it is a far more complex process than that. The MAF is one input and at lower rpms the VE table has a big impact. In fact there some big cammed cars running w/o a MAF because on high overlap cars, it can be a bigger pain than it is worth. It is pretty common to do a base tune in speed density mode (no MAF) and once it is dead on, reconnect the MAF and redo the MAF table to match.

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.

mvvette97

iTrader: (18)

I did put my stock MAF back on because it seems to run better. I don't have the screen in it though. I was just wondering do ya all think it would help just to polish the MAF to a smooth shine? I thought maybe it would make the air flow easier.

TheBlurLS1

iTrader: (8)

Don't jack with your stock MAF. /thread