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-   -   More airflow to intakes (http://www.the370z.com/intake-exhaust/71516-more-airflow-intakes.html)

Megan370z 05-19-2013 02:59 PM

Quote:

Originally Posted by synollimit (Post 2322489)
At idle you're fine but imagine at 50mph the MAF expects to see xxx amount of air, but then a huge wind blows against the car because its just a windy day. The MAF is expected to only see what it thinks it should at 50mph at whatever gear or RPM you're at. That wind blows in and it thinks the car is going faster than it really is and starts adjusting the A/F ratio. Again I've done this on other cars and it makes it super annoying to drive and it bogs, hesitates ect under light throttle and in closed loop map setting. Under WOT open loop it was fine.


the MAF sensor does NOT expect anything related to any speed.

It is just a sensor that detect airflow by the mean of a heated wire.
if a wind blow too much on it , yeah that will cool down the heated wire which send a signal that is received by the ECU then adjust the AFR.

depending on the intake bent and location of the MAF sensor, yeah it might not be good at certain occasion.

SouthArk370Z 05-19-2013 03:36 PM

Quote:

Originally Posted by Megan370z (Post 2322685)
the MAF sensor does NOT expect anything related to any speed.

It is just a sensor that detect airflow by the mean of a heated wire.
if a wind blow too much on it , yeah that will cool down the heated wire which send a signal that is received by the ECU then adjust the AFR.

depending on the intake bent and location of the MAF sensor, yeah it might not be good at certain occasion.

+1. The MAF measures, as its name implies, mass flow, not velocity or volume. As long as you are within the operating range of the sensor, pressure and velocity at the sensor are not important. If you increase the system pressure (eg, ram air) the velocity will actually decrease to get the same mass of air into the engine (the air is more dense so it takes less volume to get the same mass).

Sensor location can make a difference due to turbulence.

The setup in the OP is not a ram air but an "enhanced" CAI. For it to be a true ram air, it would have to have the filters enclosed and sealed within the new duct work.

MJB 05-19-2013 03:38 PM

1 Attachment(s)
Quote:

Originally Posted by SouthArk370Z (Post 2322719)
The setup in the OP is not a ram air but an "enhanced" CAI. For it to be a true ram air, it would have to have the filters enclosed and sealed within the new duct work.

True. I guess a true ram air would be something like...

SouthArk370Z 05-19-2013 04:35 PM

Quote:

Originally Posted by MJB (Post 2322722)
True. I guess a true ram air would be something like...

Whatever ya call it, it's still a great idea. Thanks for sharing. :tup:

synolimit 05-19-2013 05:10 PM

Quote:

Originally Posted by Megan370z (Post 2322685)
the MAF sensor does NOT expect anything related to any speed.

It is just a sensor that detect airflow by the mean of a heated wire.
if a wind blow too much on it , yeah that will cool down the heated wire which send a signal that is received by the ECU then adjust the AFR.

depending on the intake bent and location of the MAF sensor, yeah it might not be good at certain occasion.

You read to far into that. At 50mph more air will be sucked in than say 10mph. i was only using speed to make it simple instead of saying increased MAF volts at higher speeds or air sucking, which people might not have gotten.

synolimit 05-19-2013 05:22 PM

Quote:

Originally Posted by SouthArk370Z (Post 2322719)
+1. The MAF measures, as its name implies, mass flow, not velocity or volume. As long as you are within the operating range of the sensor, pressure and velocity at the sensor are not important. If you increase the system pressure (eg, ram air) the velocity will actually decrease to get the same mass of air into the engine (the air is more dense so it takes less volume to get the same mass).

Sensor location can make a difference due to turbulence.

The setup in the OP is not a ram air but an "enhanced" CAI. For it to be a true ram air, it would have to have the filters enclosed and sealed within the new duct work.

Actually it will measure velocity, volume and flow of air in a way. A turbo'd car will max out MAF sensors if they are installed in to small of a diameter tube. To small, the volume of space isn't enough and the volts increase maxing out the sensor and tuning cannot be completed or compensate for the change above 5.0v. The velocity of the air filling up a small tube to fast again will max out the sensor and tuning will hault. Yes in the end its still mass flow but factors effect flow.

Density has nothing to do with ram air. It has to do with heat. Hotter air is less desnse. Ram air at ambient temp is still the same temp as ambient air in a closed space as long as heat soak is kept at bay. The amount of air molicules entering the engine will be the same. However a ram air will cause the senser to increase fuel which is we're the bogging and hesitation come from since wind is never going to be the same driving down the road, for example a semi blowing past you rocking your car.

Baer383 05-19-2013 05:49 PM

Quote:

Originally Posted by V8Killer (Post 2322421)
Just playing devils advocate but in a full frontal collision by removing that foam would that hurt you on a insurance claim for modifying the structure of the vehicle?

No it won't when the insurance adjustors look at cars they never look at them that close and most of them don't know what they are looking at anyway.

SouthArk370Z 05-19-2013 06:22 PM

Quote:

Originally Posted by synollimit (Post 2322852)
Actually it will measure velocity, volume and flow of air in a way.

Those variables can be derived (if you know other variables), but they're not what is being measured. Ofc, even the mass flow measurement is not direct, it is derived from heat loss.

Quote:

Originally Posted by synollimit (Post 2322852)
A turbo'd car will max out MAF sensors if they are installed in to small of a diameter tube. ...

"As long as you are within the operating range of the sensor,..."

Quote:

Originally Posted by synollimit (Post 2322852)
Density has nothing to do with ram air. It has to do with heat. Hotter air is less desnse. Ram air at ambient temp is still the same temp as ambient air in a closed space as long as heat soak is kept at bay. The amount of air molicules entering the engine will be the same. However a ram air will cause the senser to increase fuel which is we're the bogging and hesitation come from since wind is never going to be the same driving down the road, for example a semi blowing past you rocking your car.

Wrong on so many levels. To start with, pressure, volume, and temperature are interrelated. (that explanation tends to be overly technical, Google "PVT" for others). If you change any of those variables, something else has to change. If you increase the pressure (ram air) and the temperature stays the same (there will be a slight increase of temp anytime you compress a gas, but not important for this discussion), the volume has to decrease. When the volume decreases, the density goes up.

The raison d'être of ram air is to increase pressure which in turn increases density which means more O2 molecules per unit of volume.

synolimit 05-19-2013 07:32 PM

Quote:

Originally Posted by SouthArk370Z (Post 2322927)
Those variables can be derived (if you know other variables), but they're not what is being measured. Ofc, even the mass flow measurement is not direct, it is derived from heat loss.

I never said they were. Simply they effect the maf voltage and make the car run poorly. hence taking all that into consideration the MAF in a away measures them and/or effected by them. This isn't a science class, its a topic that having unwanted air blown in by out side forces will make the car run like **** since its more air than what the car is supposed to be ingesting.


Quote:

Originally Posted by SouthArk370Z (Post 2322927)
"As long as you are within the operating range of the sensor,..."

You meant to say outside operating range. you cant max it out if its in the operating range!

Quote:

Originally Posted by SouthArk370Z (Post 2322927)
Wrong on so many levels. To start with, pressure, volume, and temperature are interrelated. (that explanation tends to be overly technical, Google "PVT" for others). If you change any of those variables, something else has to change. If you increase the pressure (ram air) and the temperature stays the same (there will be a slight increase of temp anytime you compress a gas, but not important for this discussion), the volume has to decrease. When the volume decreases, the density goes up.

The raison d'être of ram air is to increase pressure which in turn increases density which means more O2 molecules per unit of volume.

You are not going to increase the pressure with this setup. The piping is not changing size or acting like a compressor in any way. The term ram air in this topic is just exposing the filter to outside air. Maybe you missed the word "ram air effect." I think I have to spell things out for you since I already said I'm talking to people so they understand but you clearly can't come down a level and read whats in front of you.

SouthArk370Z 05-19-2013 08:00 PM

Quote:

Originally Posted by synollimit (Post 2322968)
... This isn't a science class, its a topic that having unwanted air blown in by out side forces will make the car run like **** since its more air than what the car is supposed to be ingesting.

But you need to have at least a little understanding of the science behind flow measurement to discuss it.

Quote:

Originally Posted by synollimit (Post 2322968)
You meant to say outside operating range. you cant max it out if its in the operating range!

No. I said exactly what I meant.


Quote:

Originally Posted by synollimit (Post 2322968)
... Maybe you missed the word "ram air effect." I think I have to spell things out for you since I already said I'm talking to people so they understand but you clearly can't come down a level and read whats in front of you.

If you don't mean "ram air" (with or without the "effect") then don't say "ram air." It will avoid a lot of confusion. How are ppl going to understand you if you don't say what you mean?

370Zsteve 05-19-2013 08:13 PM

:drama:

DEpointfive0 05-19-2013 08:18 PM

Quote:

Originally Posted by 370Zsteve (Post 2323050)
:drama:

Exactly what I was thinking

370Zsteve 05-19-2013 08:22 PM

Quote:

Originally Posted by DEpointfive0 (Post 2323058)
Exactly what I was thinking

You want butter and salt? :yum:

SouthArk370Z 05-19-2013 08:26 PM

Quote:

Originally Posted by 370Zsteve (Post 2323050)
:drama:

Quote:

Originally Posted by DEpointfive0 (Post 2323058)
Exactly what I was thinking

Welcome back, my friends, to the show that never ends. ... Come inside. Come inside. :)


( Click to show/hide )

DEpointfive0 05-19-2013 08:44 PM

Quote:

Originally Posted by 370Zsteve (Post 2323066)
You want butter and salt? :yum:

Bet your àss I do


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