Air flow MAF question

[BlackyRose]

A lot of the intake tubes (perrin, AFO) and some of the intakes (HKS) leave the MAF at the stock position. If the air is being read by the MAF before it enters the tubes, isnt the 3inch diameter and fancy bends that these intakes promote just a gimmick.

If someone mechanically inclined can explain to me how can the MAF read the air flow then somehow once the air passes the MAF and the readings have been made and then the air goes into the "smoother and bigger" tubes that improved throttle response and HP are made. Seems like in order for ALL of these companies to make these claims, you would have to move the MAF because once it reads the airflow everything AFTER the MAF is a moot point.

1. Please dont flame about "another intake thread", this is just a mechanical "flow" question that I have always been curious about....not really here to ask for the best drop in or the best intake because there are already plenty of threads for that.

Just kind of hit me last night. Maybe even though the MAF reads airflow that after it passes through these fancy intake tubes and intakes that it "magically rushes" into the engine...

[mad_sb]

The idea with the tubes is to increase the velocity by reducing turbulence and increase the volume by reducing pressure drops. The maf is just measuring the mass of air entering the engine, the tubes are designed to try and increase the mass of air, as are all other performance intakes ever made. In many cases the maf housing is also a restriction that causes pressure drop, which is why some intakes replace the maf housing. In those cases the maf needs to be re calibrated to measure the actual airflow correctly.

[BlackyRose]

Originally Posted by mad_sb

The idea with the tubes is to increase the velocity by reducing turbulence and increase the volume by reducing pressure drops. The maf is just measuring the mass of air entering the engine, the tubes are designed to try and increase the mass of air, as are all other performance intakes ever made. In many cases the maf housing is also a restriction that causes pressure drop, which is why some intakes replace the maf housing. In those cases the maf needs to be re calibrated to measure the actual airflow correctly.

But how will the engine read the increased mass of air and less turbulence if the MAF sensor has already alerted the computer all of those things at factory location point (before the benefits of the silicone tubes can be reaped). Please excuse my response if it is misinformed, but it seems like to get the true value that the MAF should be located AFTER the new tube and not BEFORE it.....hence why the high flow filters work so well because they provide improved flow readings before they hit the MAF

not fighting the process, again, just curious and want to learn so I can speak educated on intake matters

[zooki]

It depends on where the restriction in the intake tract is. If the restriction is the MAF itself, then it won't matter how big or smooth the ducting to and from the MAF meter. And personally I really don't think you'll see a difference except at wide open throttle & 7000+ RPM. Otherwise the throttle body itself is going to be the restriction in the system.

[mad_sb]

Originally Posted by BlackyRose

But how will the engine read the increased mass of air and less turbulence if the MAF sensor has already alerted the computer all of those things at factory location point (before the benefits of the silicone tubes can be reaped). Please excuse my response if it is misinformed, but it seems like to get the true value that the MAF should be located AFTER the new tube and not BEFORE it.....hence why the high flow filters work so well because they provide improved flow readings before they hit the MAF

not fighting the process, again, just curious and want to learn so I can speak educated on intake matters

It will read it because that is what the Mass Air Flow sensor does, it measures the mass of air that passes it, if you increase the velocity and reduce pressure drops in the intake sytem as a whole the mass of air ingested by the engine increases and the maf sensor reads that increase regardless of where it is located. It's a closed system air does not enter the engine without passing the maf..

[pheoxs]

Originally Posted by BlackyRose

But how will the engine read the increased mass of air and less turbulence if the MAF sensor has already alerted the computer all of those things at factory location point (before the benefits of the silicone tubes can be reaped). Please excuse my response if it is misinformed, but it seems like to get the true value that the MAF should be located AFTER the new tube and not BEFORE it.....hence why the high flow filters work so well because they provide improved flow readings before they hit the MAF

not fighting the process, again, just curious and want to learn so I can speak educated on intake matters

Think of it like a water hose. You have two hoses connected together with a 'meter' in the middle that reads flow.

If you choke the line before the meter, your flow drops and your meter reads less flow. Now go choke the line after it, same thing, you lose flow so the meter reads less flow.

[pheoxs]

Edit: double post

[wparsons]

The MAF isn't a restrictor plate, so if the bottleneck is between the MAF and the engine fixing that will increase air flow through the MAF since the air has to come through the MAF to get to the engine.

[BlackyRose]

But if the engine is "choked" at the position of the MAF, isnt everything else after that moot?

There has to be a reason that the aftermarket intakes move the MAF and place it in a larger housing