Has anyone every used a SLP 85mm MAf and if you have did it work? Could you tell a difference at all. I am considering buying one and I dont know if I should. I can get a used one for 100 bucks. I would really love some input from ya'll before I make my decision. Thanks

 

I haven't used one. However for the same money or depending how handy you are, for free you can get ported MAF Ends. Or you can hacksaw the metal posts out of your stock one. It will give you roughly the same gain as SLP's MAF. I just got some Whisper Ported MAF Ends for $110. Just a thought.

 

This is a very disputed topic. I would not reccomend touching your MAF sensor, or changing it do any aftermarket one until you are making big horsepower.

The results of an aftermarket MAF sensor are disputed and can be very random. Some have expirience gains up to 10hp, and some have lost as much as 10. Not all the cars and engines are the same so thus they will react differently to the new MAF. If a new sensor messes up the tuning, you can get the car tuned which might help, but can be expensive.

If you insist on doing something with the MAF sensor, just de-screen it. Some people have seen gains up to 3hp doing this. Rarely will it cause any trouble codes. Porting the MAF housing is something I would not reccomend. Again, the results seem to re fairly random, some "felt" a difference w/o any problems, and other got trouble codes. I am one of the ones who has gotten trouble codes with my ported MAF ends. Even if I clear it, it will come back on in a couple miles. I am currently searcing for some stock MAF ends to put back on. The results from porting the MAF ends are nearly a toss-up. Could see some benefit, but if you don't, you will be paying for new ends which are rare, and you will probably have to buy the whole sensor.

 

If you have an A4 do not do a ported MAF, it will over time slow your shifts down, and the SlP over size MAF is a Truck Maf that has been programmed for our engines, but would only be benifitial if you have cam and heads and making alot of HP. If your stock it may give you a slit increase in HP but make you lean, and if you plan on adding aftermarket parts that lean you out you will end up to lean.

 

When I first put it on the ol' butt o'meter said hell yeah .. the car was more responsive and seemed quicker ... took out to the track to give it whirl.

Started out mid 13s @ about 105 ... by the end of the night, as the PCM learned the MAF, I was running low 14s @ 99 and threw an SES ...

Took it to the shop the next day, put Tech II on it and it was running lean w/3* KR ...

JMO ... AM MAFs are a gamble especially for the price ... and I would put absolutely no stock in what any one sez abuout MAF performance, unless they can back it up with track times or dyno runs ...

Good Luck

 

That's why you need a GMAFS if you're gonna go through the trouble of messing with the MAF sensor. The got them things tuned so it doesn't allow the computer to "re-learn" a fuel curve. I'm glad I got mine...and I did notice a difference. Only problem is, you gotta pay if you wanna play.

 

How much does it cost to play?

 

The SLP 85mm as well as the PACE MAF are also "calibrated" ... If you want to adjust your fuel adn timing curves ... do it directly with tuning in the PCM ... the GMAF is just a more expensive gamble ... again "noticing a difference" is not the same as quantifying it with a battery of track runs and/or dyno results ...

Also I understand Granatelli had a beef with thier manufacturer and are now supposedly selling what is essentially a stock MAF with ported ends ... M

 

Well I have had my ported MAF Ends on for 2 days now and no codes, no bogging ..can't say I really "feel" anything. Going to the track tomorrow so we will see there. I have ran the **** out of it the last 2 days so I know my fuel tables have already adjusted. I cannot see how unrestriciting air flow, which is all porting does, causes you to run lean. That would happen by putting on a performance lid, cold air induction or smooth bellows as well then wouldn't it? They all improve air flow and unrestrict the air that the stock parts restrict. Again I am not saying a bigger MAF just porting the ends.

 

Marstaut....I noticed your 13.34 time in your sig. I am running 13.35 on low tread street tires. I want to get 3.73's ...but looking at your time I am not sure if I should. It really seems you should be getting more than 13.34. Anyway, did you like your upgrade to 3.73's?

 

Hey isn't this cool We agree on this one.
Changing, modding, or screwing with your MAF is a total crap shoot. I run the numbers in my sig with a stock MAF and I will NOT change it until I'm running a heavily modded engine.

And it's not about freeing up air flow. It's the lieing to the computer that causes problems.

 

Everyone is free to correct me here. This is my understanding. Based on my own logic and limited experience with aftermarket or modded MAFs.

A "Mass Air Flow" sensor detects the amount of air shooting through the tube. It does this by measuring the speed at which the air is moving as it passes over the sensors. It "thinks" it knows what the diameter of the tube is and can therefore "calculate" the volume of air being supplied to the engine.

If you woller out the hole it lets more air in that the computer doesn't know about and that makes a lean condition. Of course the O2 sensors will pick up on the lean condition and add more fuel. But they might not and then you get ping. Then knock retard and less power. Which helps you keep traction to the rear wheels like it or not.

That's my theory anyway. Do what you will with it. I think the stock MAF is plenty big enough for a car with less than 400 hp.

 

So what do you think happens when you put on a performance air lid? You "increase" the speed of the air flow by reducing the amount of restrictive material. Less restriction = faster air flow. So you are already increasing the air speed hitting the MAF. If you install a cold air package you are "speeding up" the air flow. So I am not sure I am in agreement with your theory as far as porting goes.

 

2002Z28SSConv is partially right ... except it's not the MAF that's calculating the volume of air, it's the PCM based on the input from the MAF - airspeed - and the AIT - air temp.

It's the PCM that knows what size the MAF is and what the values will be for a given airspeed and can select the fuel and timing tables accordingly.

You can shove more air into the MAF, with a lid or CAI and the PCM will make the correct calculations because the MAF parameters still match the calibaration tables in the PCM, i.e it will know what the increased air flow is ... more air plus more fuel simply means more ponies.

But, change the the measuring device - the MAF - and the PCM's calculations are now invalid, because the input data is now wrong when bounced against the PCM's tables.

If you're lucky the values won't be too far off and the engine will simply lean out little ... because based on MAF values, the PCM is no longer making the correct air volume calculations ... if it leans it out too far, then the O2s pick up the lean condition and the PCM will begin to adjust, if you're lucky you're no worse than where you started, as far as HP and maybe even a pony or two more ... if the lean condition is too radical the PCM will start to pull timing or in my case throw an SES ...

If you have an A4, the PCM will also use the MAF inputs to determine engine load and set the transmission line pressure accordiningly. With an AM MAF the PCM will determine the load is actually less than it is and reduce the line pressure ... this can cause excessive wear and tear on your A4 ...

That said, I have a Z06 MAF that I'm going to try sometime in the future ... but I'm also going to load the Z06 MAF tables into my PCM ... and my A/FR will be tuned on the dyno at the same time ... M

 

Porting is not the same as putting on a bigger MAF. Now that that is clear, you are still using the same size MAF even if you port it. If the MAF senses more air and adds more fuel because you add a lid, then why would it not do the same if you port your MAF ends? You are doing the same thing which is unrestricitng air flow. The MAF is still the same size. You have just removed the restricitve ends that create turbulence in the air flow. you are still pumping in the same amount of air. It is just able to travel easier and faster. I can understand adding a bigger MAF causing problems, but porting the ends is the same philosophy and physics as an air lid or CAI kit.

So if the PCM is looking at the speed of the air flow then why does it not lean out your mixture when you add a CAI? I mean adding a CAI does the same as forcing 10lbs of flour in a 5 pound sack. It will force the air in at "HIGHER SPEEDS" than stock.

A Lid removes the restrictive baffles removing the turbulance caused by the stock piece. So you are still taking in the same if not more air and at "Higher Speeds" cause you do not use the stock resonator box. That right there would generate a lean condition based on what you are saying.

So tell me why porting the MAF ends makes you run lean and nothing else does? Do you think the stock MAF Ends "slow down" the faster air you are getting from your CAI and Lid? If it were then you would gain nothing from those mods.