Mustang GT and K&N air charger

Michael Johnson > wrote in
:

> C. E. White wrote:
>> "Michael Johnson" > wrote in message
>> ...
>>
>>> Haven't we beat this to death between us? I was replying to WF
>>> because you and I are never going to agree on this issue.
>>
>> We beat it to death long ago. I just can't turn away. You clearly
>> don't understand how modern feedback fuel injection systems work and
>> because of this you are drawing bad conclusions. Foolishly, I hope I
>> can make a subtle change in my arguments so that you can understand
>> that unless you are at wide open throttle, the restriction of the air
>> filter is largely irrelevant as far as the performance of the engine
>> is concerned. Except at WOT, the throttle plate is the final
>> adjustment to the air flow rate. If you increase the restriction in
>> another part of the intake tract, you can open the throttle a little
>> more to get the same overall flow restriction. This doesn't effect
>> fuel economy because the PCM has the ability to correct the A/F ratio
>> based on the output of the O2 sensors (as long as the restriction is
>> not so gross as to set the malfunction indicator). The system is
>> designed to be able to compensate for changes like increasing air
>> filter restriction, drift in the response of the various sensors,
>> altitude, etc. Compared to other changes over time, a minor increase
>> in the flow restriction related to the air filter is trivial. Until
>> you understand this, you'll continue to draw the wrong conclusion.
>
> Ed, let it go. Mileage doesn't drop from a dirty filter at some
magical
> point. It is a gradual reduction that gets progressively more
> noticeable as the filter collects more dirt.

I can see each side of this, and each argument makes sense in its own
right. That said, the only thing that will put this to bed is honest,
real world test results, which seem to be in short supply these days.

Joe wrote:
> Michael Johnson > wrote in
> :
>
>> C. E. White wrote:
>>> "Michael Johnson" > wrote in message
>>> ...
>>>
>>>> Haven't we beat this to death between us? I was replying to WF
>>>> because you and I are never going to agree on this issue.
>>> We beat it to death long ago. I just can't turn away. You clearly
>>> don't understand how modern feedback fuel injection systems work and
>>> because of this you are drawing bad conclusions. Foolishly, I hope I
>>> can make a subtle change in my arguments so that you can understand
>>> that unless you are at wide open throttle, the restriction of the air
>>> filter is largely irrelevant as far as the performance of the engine
>>> is concerned. Except at WOT, the throttle plate is the final
>>> adjustment to the air flow rate. If you increase the restriction in
>>> another part of the intake tract, you can open the throttle a little
>>> more to get the same overall flow restriction. This doesn't effect
>>> fuel economy because the PCM has the ability to correct the A/F ratio
>>> based on the output of the O2 sensors (as long as the restriction is
>>> not so gross as to set the malfunction indicator). The system is
>>> designed to be able to compensate for changes like increasing air
>>> filter restriction, drift in the response of the various sensors,
>>> altitude, etc. Compared to other changes over time, a minor increase
>>> in the flow restriction related to the air filter is trivial. Until
>>> you understand this, you'll continue to draw the wrong conclusion.
>> Ed, let it go. Mileage doesn't drop from a dirty filter at some
> magical
>> point. It is a gradual reduction that gets progressively more
>> noticeable as the filter collects more dirt.
>
> I can see each side of this, and each argument makes sense in its own
> right. That said, the only thing that will put this to bed is honest,
> real world test results, which seem to be in short supply these days.

Agreed.

Michael Johnson wrote:
> Joe wrote:
>> Michael Johnson > wrote in
>> :
>>
>>> C. E. White wrote:
>>>> "Michael Johnson" > wrote in message
>>>> ...
>>>>
>>>>> Haven't we beat this to death between us? I was replying to WF
>>>>> because you and I are never going to agree on this issue.
>>>> We beat it to death long ago. I just can't turn away. You clearly
>>>> don't understand how modern feedback fuel injection systems work and
>>>> because of this you are drawing bad conclusions. Foolishly, I hope I
>>>> can make a subtle change in my arguments so that you can understand
>>>> that unless you are at wide open throttle, the restriction of the
>>>> air filter is largely irrelevant as far as the performance of the
>>>> engine is concerned. Except at WOT, the throttle plate is the final
>>>> adjustment to the air flow rate. If you increase the restriction in
>>>> another part of the intake tract, you can open the throttle a little
>>>> more to get the same overall flow restriction. This doesn't effect
>>>> fuel economy because the PCM has the ability to correct the A/F
>>>> ratio based on the output of the O2 sensors (as long as the
>>>> restriction is not so gross as to set the malfunction indicator).
>>>> The system is designed to be able to compensate for changes like
>>>> increasing air filter restriction, drift in the response of the
>>>> various sensors, altitude, etc. Compared to other changes over time,
>>>> a minor increase in the flow restriction related to the air filter
>>>> is trivial. Until you understand this, you'll continue to draw the
>>>> wrong conclusion.
>>> Ed, let it go. Mileage doesn't drop from a dirty filter at some
>> magical
>>> point. It is a gradual reduction that gets progressively more
>>> noticeable as the filter collects more dirt.
>>
>> I can see each side of this, and each argument makes sense in its own
>> right. That said, the only thing that will put this to bed is honest,
>> real world test results, which seem to be in short supply these days.
>
> Agreed.

I think I said something similar to that several weeks ago....

--
"Yah know I hate it when forces gather in ma' fringe..." - Sheogorath

"Daytime television sucked 20 years ago,
and it still sucks today!" - Marc Bissonette

"Joe" > wrote in message
...
> Michael Johnson > wrote in
> :
>
>> C. E. White wrote:
>>> "Michael Johnson" > wrote in message
>>> ...
>>>
>>>> Haven't we beat this to death between us? I was replying to WF
>>>> because you and I are never going to agree on this issue.
>>>
>>> We beat it to death long ago. I just can't turn away. You clearly
>>> don't understand how modern feedback fuel injection systems work and
>>> because of this you are drawing bad conclusions. Foolishly, I hope I
>>> can make a subtle change in my arguments so that you can understand
>>> that unless you are at wide open throttle, the restriction of the air
>>> filter is largely irrelevant as far as the performance of the engine
>>> is concerned. Except at WOT, the throttle plate is the final
>>> adjustment to the air flow rate. If you increase the restriction in
>>> another part of the intake tract, you can open the throttle a little
>>> more to get the same overall flow restriction. This doesn't effect
>>> fuel economy because the PCM has the ability to correct the A/F ratio
>>> based on the output of the O2 sensors (as long as the restriction is
>>> not so gross as to set the malfunction indicator). The system is
>>> designed to be able to compensate for changes like increasing air
>>> filter restriction, drift in the response of the various sensors,
>>> altitude, etc. Compared to other changes over time, a minor increase
>>> in the flow restriction related to the air filter is trivial. Until
>>> you understand this, you'll continue to draw the wrong conclusion.
>>
>> Ed, let it go. Mileage doesn't drop from a dirty filter at some
> magical
>> point. It is a gradual reduction that gets progressively more
>> noticeable as the filter collects more dirt.
>
> I can see each side of this, and each argument makes sense in its own
> right. That said, the only thing that will put this to bed is honest,
> real world test results, which seem to be in short supply these days.

There is plenty real world proof that:
1. Filters alone change the airflow restrictions in modern EFI cars enough
to dramatically effect their horsepower and fuel mileage.
2. Filters alone can and do alter the airflow beyond the stock engine
management computers ability to correct.

The real world results are overwhelming! None of them support Ed's
misguided positions on this.

Tuning, needed or not? YES! I made the dyno runs like this, on the first car
I installed the stock air box and ran it three times and then installed the
Bullitt airbox and did the same. With both intakes I had the stock tune
installed in the car. Sure enough with the stock airbox and tune it went
rich down to the high 11's and low 12's like normal. When I installed the
Bullitt airbox it went lean, very very lean, in the mid to high 14's. Yes,
this intake requires a tune. Any tuner can verify this as well by looking at
the stock Bullitt tune, which SCT has in their database, and noting that the
MAF adjustments are different for the new Bullitt air box.
http://forums.bradbarnett.net/showthread.php?t=75262

http://www.allfordmustangs.com/revie...hp/product/394

"WindsorFox-{SS}-" > wrote in message
news:UEroj.576

> It seems more like you don't get it. If the filter is clogged
> enough it can still restrict more than the throttle at part way.

Again, I am not talking about some wildly contaminate filter. I am
talking about a normally serviced filter. A filter that is so
contaminated that it will significantly effect fuel economy will be
outside the range the PCM can compensate for and in response, the PCM
should turn on the check engine light.

I keep repeating I am not talking about some hypothetical case where
the filter is absurdly contaminated. I am talking about normal
filters, in normal sorts of use, replaced at the proper intervals -
NOT SOME HYPOTHETICAL FILTER SO PLUGGED THAT IT IS MORE RESTRICTIVE
THAN THE THROTTLE PLATE UNDER NORMAL DRIVING CONDITIONS.

And most especially I am talking about a comparison between a K&N
filter and a standard paper filter in reasonable condition.

Ed

"Michael Johnson" > wrote in message
...
> C. E. White wrote:
>> "Michael Johnson" > wrote in message
>> ...
>>
>>> Haven't we beat this to death between us? I was replying to WF
>>> because you and I are never going to agree on this issue.
>>
>> We beat it to death long ago. I just can't turn away. You clearly
>> don't understand how modern feedback fuel injection systems work
>> and because of this you are drawing bad conclusions. Foolishly, I
>> hope I can make a subtle change in my arguments so that you can
>> understand that unless you are at wide open throttle, the
>> restriction of the air filter is largely irrelevant as far as the
>> performance of the engine is concerned. Except at WOT, the throttle
>> plate is the final adjustment to the air flow rate. If you increase
>> the restriction in another part of the intake tract, you can open
>> the throttle a little more to get the same overall flow
>> restriction. This doesn't effect fuel economy because the PCM has
>> the ability to correct the A/F ratio based on the output of the O2
>> sensors (as long as the restriction is not so gross as to set the
>> malfunction indicator). The system is designed to be able to
>> compensate for changes like increasing air filter restriction,
>> drift in the response of the various sensors, altitude, etc.
>> Compared to other changes over time, a minor increase in the flow
>> restriction related to the air filter is trivial. Until you
>> understand this, you'll continue to draw the wrong conclusion.
>
> Ed, let it go. Mileage doesn't drop from a dirty filter at some
> magical point. It is a gradual reduction that gets progressively
> more noticeable as the filter collects more dirt.

Tell me why you believe this to be true. Why is the PCM unable to
correct the A/F ratio. Exactly why is the restriction imposed by the
air filter uniquely different than the restriction imposed by the
throttle plate. AND AGAIN, I AM NOT TALKING ABOUT SOME HYPOTHETICAL
FILTER THAT IS ABSURDLY CONTAMINATED.

I have a hard time letting it go because you aren't getting it right.
get it. Modern EFI feedback systems are designed to compensate for
exactly the sort of gradual changes associated with things like
changes in the restriction of an air filter, the drift of sensors like
the MAF and TPS, etc. You seem to think that air filters become very
restrictive over time. This is simply not true if they are serviced
per the manufacturer's recommendations. We are talking about
restrictions that range from less than 0.05 psi for a new filter to
0.5 psi for a heavily used filter (I'll bet you've never seen one this
contaminated). This is a change on the order of tenths of a psi. At
cruise the difference between atmospheric pressure and manifold
pressure is in the rage of 5 to 8 psi. The air filter contributes less
than 1% of this pressure drop, even for a restrictive filter. As I
pointed out before, drift in the TPS sensor is on the order of +/-10%.
If you doubled the pressure drop across the air filter, it will be an
insignificant factor in the total pressure drop between the atmosphere
and the cylinders. It is simply ridiculous to believe that the PCM can
compensate for a 10% drift in the output of the TPS or the MAF
sensors, but cannot handle a 1% drift in the restriction of the intake
tract.

Ed

"WindsorFox" > wrote in message
...

> I think I said something similar to that several weeks ago....

And I pointed you guys to the Consumer Reports article where they said
a dirty air filter doesn't significantly affect fuel economy
(http://www.consumerreports.org/cro/c...l-dollars-406/
or http://tinyurl.com/2datps.

I even tracked down the source of the EPA claim that a dirty air
filter could reduce fuel economy by up to 10% (it is based on data
analysis by a company called Energy and Environmental Analysis, Inc.)
I e-mailed the company and discovered they have no actual test data to
back up this claim. They are basing it on studies of vehicles that
failed the OBDII test because the check engine light was on. I've
never claimed that a filter that was so restrictive that it turned on
the check engine light would not affect fuel economy. I am only
addressing reasonably contaminated air filters. And actually this
thread got started because I disparaged the notion that K&N air
filters can improve the fuel economy of a properly maintained modern
fuel injected car.

Ed

"C. E. White" > wrote in message
news:47a32f9b$1@kcnews01...
>
> "Michael Johnson" > wrote in message
> ...
>> C. E. White wrote:
>>> "Michael Johnson" > wrote in message
>>> ...
>>>
>>>> Haven't we beat this to death between us? I was replying to WF because
>>>> you and I are never going to agree on this issue.
>>>
>>> We beat it to death long ago. I just can't turn away. You clearly don't
>>> understand how modern feedback fuel injection systems work and because
>>> of this you are drawing bad conclusions. Foolishly, I hope I can make a
>>> subtle change in my arguments so that you can understand that unless you
>>> are at wide open throttle, the restriction of the air filter is largely
>>> irrelevant as far as the performance of the engine is concerned. Except
>>> at WOT, the throttle plate is the final adjustment to the air flow rate.
>>> If you increase the restriction in another part of the intake tract, you
>>> can open the throttle a little more to get the same overall flow
>>> restriction. This doesn't effect fuel economy because the PCM has the
>>> ability to correct the A/F ratio based on the output of the O2 sensors
>>> (as long as the restriction is not so gross as to set the malfunction
>>> indicator). The system is designed to be able to compensate for changes
>>> like increasing air filter restriction, drift in the response of the
>>> various sensors, altitude, etc. Compared to other changes over time, a
>>> minor increase in the flow restriction related to the air filter is
>>> trivial. Until you understand this, you'll continue to draw the wrong
>>> conclusion.
>>
>> Ed, let it go. Mileage doesn't drop from a dirty filter at some magical
>> point. It is a gradual reduction that gets progressively more noticeable
>> as the filter collects more dirt.
>
> Tell me why you believe this to be true. Why is the PCM unable to correct
> the A/F ratio. Exactly why is the restriction imposed by the air filter
> uniquely different than the restriction imposed by the throttle plate. AND
> AGAIN, I AM NOT TALKING ABOUT SOME HYPOTHETICAL FILTER THAT IS ABSURDLY
> CONTAMINATED.


IGNORING THE TRUTH WON'T MAKE IT GO AWAY ED!

Tuning, needed or not? YES! I made the dyno runs like this, on the first car
I installed the stock air box and ran it three times and then installed the
Bullitt airbox and did the same. With both intakes I had the stock tune
installed in the car. Sure enough with the stock airbox and tune it went
rich down to the high 11's and low 12's like normal. When I installed the
Bullitt airbox it went lean, very very lean, in the mid to high 14's. Yes,
this intake requires a tune. Any tuner can verify this as well by looking at
the stock Bullitt tune, which SCT has in their database, and noting that the
MAF adjustments are different for the new Bullitt air box.
http://forums.bradbarnett.net/showthread.php?t=75262


Dyno testing the 2005 GT has shown that the computer is so sensitive to
airflow changes that a computer modification is necessary in order to
control the air/fuel ratio at the proper level. Installing this air intake
assembly on a 2005 GT without any tuning will result in a leaner-than-ideal
14:1 air/fuel ratio. While certainly not lean enough to cause engine
durablility concerns, it is leaner than what is desired for optimum
performance. Even when replacing the air filter ONLY to a higher flow
assembly, the air/fuel ratio leans out at an alarming rate.
http://www.allfordmustangs.com/revie...hp/product/394







>
> I have a hard time letting it go because you aren't getting it right. get
> it. Modern EFI feedback systems are designed to compensate for exactly the
> sort of gradual changes associated with things like changes in the
> restriction of an air filter, the drift of sensors like the MAF and TPS,
> etc. You seem to think that air filters become very restrictive over time.
> This is simply not true if they are serviced per the manufacturer's
> recommendations. We are talking about restrictions that range from less
> than 0.05 psi for a new filter to 0.5 psi for a heavily used filter (I'll
> bet you've never seen one this contaminated). This is a change on the
> order of tenths of a psi. At cruise the difference between atmospheric
> pressure and manifold pressure is in the rage of 5 to 8 psi. The air
> filter contributes less than 1% of this pressure drop, even for a
> restrictive filter. As I pointed out before, drift in the TPS sensor is on
> the order of +/-10%. If you doubled the pressure drop across the air
> filter, it will be an insignificant factor in the total pressure drop
> between the atmosphere and the cylinders. It is simply ridiculous to
> believe that the PCM can compensate for a 10% drift in the output of the
> TPS or the MAF sensors, but cannot handle a 1% drift in the restriction of
> the intake tract.
>
> Ed
>

"My Name Is Nobody" > wrote in message
news:Clroj.23795$8i.15080@trndny09...
>
> "C. E. White" > wrote in message
> news:47a2312a$1@kcnews01...
>>
>> "Michael Johnson" > wrote in message
>> ...
>>
>>> Haven't we beat this to death between us? I was replying to WF
>>> because you and I are never going to agree on this issue.
>>
>> We beat it to death long ago. I just can't turn away. You clearly
>> don't understand how modern feedback fuel injection systems work
>> and because of this you are drawing bad conclusions.
>
>
> Nice Fantasy Ed.
>
> "Also included in this package is a new high flow conical filter
> assembly, custom filter shroud that separates it from the engine
> compartment heat, MAF mounting bracket, mounting hardware,
> installation tool and instructions. Dyno testing the 2005 GT has
> shown that the computer is so sensitive to airflow changes that a
> computer modification is necessary in order to control the air/fuel
> ratio at the proper level. Installing this air intake assembly on a
> 2005 GT without any tuning will result in a leaner-than-ideal 14:1
> air/fuel ratio. While certainly not lean enough to cause engine
> durablility concerns, it is leaner than what is desired for optimum
> performance. Even when replacing the air filter ONLY to a higher
> flow assembly, the air/fuel ratio leans out at an alarming rate.
> This means that any 2005 Mustang owner who is interested in
> modifying their new car for better performance will have to use some
> form of tuning"
> http://www.allfordmustangs.com/revie...hp/product/394

We coverred this before. Did you even bother to read what C&S is
selling. This advertisement is talking about a "complete
throttle-body forward package" that includes a large bore MAF. Clearly
the stock PCM needs to be modified if you change the MAF to a
completely different design. Please note that the company also sells
an alternate system, that doesn't require modifying the PCM
programing. I don't see any data to support the line that says
"replacing the air filter ONLY to a higher flow assembly, the air/fuel
ratio leans out at an alarming rate." I am not even sure what this
means. Does this apply to an otherwise stock engine? How did they
measure the A/F Ratio? Just what is "alarming" since in another line
they claim making a major change including a new large bore MAF didn't
lean the engine out enough to cause engine damage. Was the A/F ratio
measured at wide open throttle? Did they drive the car long enough
after changing the air filter to allow the PCM to adapt to the change
(by altering the long term fuel trim parameter)? The engine runs open
loop at WOT, and unless the PCM has had a chance to learn a new long
term fuel trim values, the WOT A/F ratio might be less than ideal.
However if you complete a drive cycle, the new long term trim value
should compensate for any reasonable changes in the intake tract (and
I don't consider a compeltely different large bore MAF to be a
reasonable change). At any rate, I am not talking about WOT operation.
If you are driving around at WOT a lot of the time, you aren't really
interested in what happens to fuel economy. If their modifications
changed parameters so much that the PCM can't correct the A/F ratio to
the ideal range (as defined by Ford, not C&S), then the PCM will turn
on the check engine light. If this is on, you are talking about
conditions outside of what I am talking about.

> Do you have any actual real world data to support your position?
> Any at all?
> I'm talking real world automotive air flow data, not paragraphs of
> hot air.

Where is your real world data? Quoting some advertisement for a
complete intake system is hardly "data" to refute my claim. I've never
claimed that you couldn't screw up an intake system enough to effect
performance (including gas mileage). My only claim is that fuel
mileage is not going to be significantly affected (measurable by a
consumer) by the normal sorts of changes in a properly maintained air
filter (including changing from a clean paper filter to a clean K&N
filter).

How much air do you think you need to flow to go 65 mph? If your car
gets 25 mpg, you are using about 0.25 lbs of gasoline per mile, or .23
per minute. To burn this much gasoline, you need about 3.2 lbs of air.
At standard conditions, this is about 40 cubic feet of air. So to
cruise at 65, you only need to flow around 40 cfm per minute, not the
hundreds of cfm that C&S is trying to sell you on. Like all good
advertising, C&S try to emphasize the performance of their product.
They have a chart comparing the restrcition of their intake to the
stock intake at
http://www.cnlperformance.com/images...ACER_Flow2.jpg. The
chart starts at 450 cfm and goes up 1100. Nobody is sucking in 1100
cfm with a streetable car. They are showing that it takes a pressure
drop of around 20 inches of water to suck 450 cfm through a standard
2005 Ford GT intake. This is a pressure drop of 0.72 psi. What do you
suppose the pressure drop would be at 40 cfm? If you tried to
interpolate from their chart, it is going to look a lot like zero (but
rally it is probably a lot like .05 psi).

Try to keep within the bounds of what I am claiming.

Ed

"My Name Is Nobody" > wrote in message
news:IJqoj.4954$1f.3519@trndny02...

> Until you actually move from the realm of theory into practical
> application, you'll never understand how it actually works.

Until you quit quoting advertisements that are completely out of the
range what I am talking about, you'll continue to be confused. See my
other reply in this thread.

Ed