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Dealer is telling me not to use a drop in hi-flow filter without an engine tune because the increased airflow will make the engine run to lean and result in damage.I would think disconnecting the battery and resetting the engine would allow the engine to quickly adjust the computer for the increased flow and it would in turn adjust the air/fuel mixture and correct itself...any thoughts or experience would be appreciated!!
 
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The drop-in K&N filter will do nothing to the engine computer, nor offer much of a change in airflow.

The reason cold air intakes require tunes is due to the increase in size of the Mass Airflow Sensor housing which changes the voltage reading to the ECU. This is corrected with a tune to prevent the fuel mixture from going lean and possibly cause damage.
 

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Basically what Grimace said. You only need a tune when you change the diameter of the MAF housing. This changes the speed of the air flowing past the MAF, not just the amount of air. If the MAF sensor doesn't know that even at a lower speed more air is getting in, your motor will lean out and you'll do some serious damage.

The K&N only allows more air through the paper filter.
 

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No tune required or needed. You don't need to disconnect the battery either. Just drop in and go.
 

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Dealer is telling me not to use a drop in hi-flow filter without an engine tune because the increased airflow will make the engine run to lean and result in damage.I would think disconnecting the battery and resetting the engine would allow the engine to quickly adjust the computer for the increased flow and it would in turn adjust the air/fuel mixture and correct itself...any thoughts or experience would be appreciated!!
Ignorant dealers like this is why I am afraid to mod my car :nono:
 

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Someone posted a test on here of paper vs. drop in K&N and a clean paper filter actually flowed more air.
Interesting, I've never seen that in any test. Could you link it?

K&N actually sometimes gets flack for letting too much debris as a side affect of it's more open element.
 

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@KOSS
In simple terms…
The Mass Air Sensor is a measurement device, calibrated to a specific diameter of inlet tube, by the amount of pressure applied to the MAS it calculates the amount of air flowing thru the inlet tube…
Changing the air filter to a more volumetric design allowing more air to flow thru the same inlet tube should not be an issue… Diameter(K Factor) x pressure, temperature corrected equals CFM
Changing inlet tube diameter to a larger size, different K factor, will cause a miss calculation of the volume flowing to the engine…. This will result in the engine running leaner due to the fact more air (larger volume) is being consumed by the engine then the PCM has calculated for in the air fuel mixture… That is why a tune is needed for an after marker CAI to change the K factor and calculate the correct amount of volume of air being consumed by the engine…
I am in Gas measurement and this is the basics for a Pitot Tube designed measurement device and this is the same design theory as in the MAS and the speedo on an airplane…
But an airplanes works a little different than your Mustangs MAS…
Questions?

Now towards the link to BrenSpeeds test... I like BrenSpeed and I have purchased items from them... but I say BS on the dyno of a stock car making 418 RWHP... check your dyno... yeah right the engine makes 475+ at the crank being stock...
The car was not stock so it is a bogus test...
 

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Damn my dealer helped me put mine in. They just wanted to make sure I put a paper one back in V6:winks:kooky:is ur dealer
 

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@KOSS
In simple terms…
The Mass Air Sensor is a measurement device, calibrated to a specific diameter of inlet tube, by the amount of pressure applied to the MAS it calculates the amount of air flowing thru the inlet tube…
Changing the air filter to a more volumetric design allowing more air to flow thru the same inlet tube should not be an issue… Diameter(K Factor) x pressure, temperature corrected equals CFM
Changing inlet tube diameter to a larger size, different K factor, will cause a miss calculation of the volume flowing to the engine…. This will result in the engine running leaner due to the fact more air (larger volume) is being consumed by the engine then the PCM has calculated for in the air fuel mixture… That is why a tune is needed for an after marker CAI to change the K factor and calculate the correct amount of volume of air being consumed by the engine…
I am in Gas measurement and this is the basics for a Pitot Tube designed measurement device and this is the same design theory as in the MAS and the speedo on an airplane…
But an airplanes works a little different than your Mustangs MAS…
Questions?

Now towards the link to BrenSpeeds test... I like BrenSpeed and I have purchased items from them... but I say BS on the dyno of a stock car making 418 RWHP... check your dyno... yeah right the engine makes 475+ at the crank being stock...
The car was not stock so it is a bogus test...
Is the engine control system on these engines not a "closed loop" type, capable of adjusting the inlet fuel mixture based on the exhaust sensor?

TV
 

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@KOSS
In simple terms…
The Mass Air Sensor is a measurement device, calibrated to a specific diameter of inlet tube, by the amount of pressure applied to the MAS it calculates the amount of air flowing thru the inlet tube…
Changing the air filter to a more volumetric design allowing more air to flow thru the same inlet tube should not be an issue… Diameter(K Factor) x pressure, temperature corrected equals CFM
Changing inlet tube diameter to a larger size, different K factor, will cause a miss calculation of the volume flowing to the engine…. This will result in the engine running leaner due to the fact more air (larger volume) is being consumed by the engine then the PCM has calculated for in the air fuel mixture… That is why a tune is needed for an after marker CAI to change the K factor and calculate the correct amount of volume of air being consumed by the engine…
I am in Gas measurement and this is the basics for a Pitot Tube designed measurement device and this is the same design theory as in the MAS and the speedo on an airplane…
But an airplanes works a little different than your Mustangs MAS…
Questions?

Now towards the link to BrenSpeeds test... I like BrenSpeed and I have purchased items from them... but I say BS on the dyno of a stock car making 418 RWHP... check your dyno... yeah right the engine makes 475+ at the crank being stock...
The car was not stock so it is a bogus test...

Our test car had Kooks long tube headers on it, this is where the 418rwhp comes from.
 
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@KOSS
In simple terms…
The Mass Air Sensor is a measurement device, calibrated to a specific diameter of inlet tube, by the amount of pressure applied to the MAS it calculates the amount of air flowing thru the inlet tube…
Changing the air filter to a more volumetric design allowing more air to flow thru the same inlet tube should not be an issue… Diameter(K Factor) x pressure, temperature corrected equals CFM
Changing inlet tube diameter to a larger size, different K factor, will cause a miss calculation of the volume flowing to the engine…. This will result in the engine running leaner due to the fact more air (larger volume) is being consumed by the engine then the PCM has calculated for in the air fuel mixture… That is why a tune is needed for an after marker CAI to change the K factor and calculate the correct amount of volume of air being consumed by the engine…
I am in Gas measurement and this is the basics for a Pitot Tube designed measurement device and this is the same design theory as in the MAS and the speedo on an airplane…
But an airplanes works a little different than your Mustangs MAS…
Questions?

Now towards the link to BrenSpeeds test... I like BrenSpeed and I have purchased items from them... but I say BS on the dyno of a stock car making 418 RWHP... check your dyno... yeah right the engine makes 475+ at the crank being stock...
The car was not stock so it is a bogus test...
Mass Airflow Sensors in 99% of modern cars utilize the hot-film method where the ECU sends a known voltage(usually 5v) into the sensor where it goes over a resistor and heats it. When air flows over the resistor it cools and changes resistance, sending a signal voltage back to the ECU to be interpreted as the flow and temperature of the air into the engine.

With the engine off the sensor may read around 1v that goes up when the engine starts and runs. When you hear people say they "pegged the MAF" it is because the airflow signal back to the ECU has matched the reference(5v) voltage that is going into the sensor and can no longer be accurately measured.

Increasing the diameter of the inlet pipe will reduce the signal from the MAF to the ECU due to the slower velocity of the incoming air. The tune will correct how the ECU interprets the signal voltage from the sensor to the correct airflow the engine is actually seeing.

There is a seperate sensor for intake air pressure, measured after the throttle body.
 
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