Mustang GT and K&N air charger

"Ed White" wrote in message news: snipped-for-privacy@corp.supernews.com...

> or . This is a reprint of a Consumer Report > article. Here is the relevant portion ->

For how many tanks full of gas? Where is their test criteria? This one reference to some unknown so far undocumented clean versus dirty filter comparison is meaningless without more information.

That's

Besides, the 3.0 liter SHO engines heads flowed more CFM of air per cylinder than the two barrel 5.8 (351) liter Cleveland V-8. The stock airflow system was simply inadequate, if the stock air flow exceeds the engines requirement, your position could look reasonable. When it does not (as with SHO), the engines maximum EFFICIENCY can not be achieved, no matter what the engine management system does. Think racing restrictor plates here. The stock filter in my case with the SHO was a physical restriction to maximum efficiency.

ED, you are off the mark on this one.

Here are a few links of Dyno documented air flow improvements with resulting efficiency increases on MAF EFI engines. Note all current stock engine management systems cannot adjust for improved airflow.

The first step was to get some base horsepower numbers. Our first dyno run with the car netted 455.4 horsepower and 433.2 lb-ft torque. According to Adam, this falls right in line with several other tests he has done with stock GT500's. Next up was installing the K&N kit. Installation was very simple, and the K&N intake bolts into the stock location and fits nicely under the strut tower brace as claimed. With the new intake installed, we put the car back on the dyno to get the new numbers. The result? 483.5 horsepower and 453.6 lb-ft torque, a gain of 28.1 horsepower and 20.4 lb-ft torque.

Turns out, we should be more trusting. You see, the air filter we inspected the first time looked fine because the delamination problem isn't visible. SVT Engineering Manager Bill Woebkenberg later explained that the problem isn't obvious because it doesn't occur until there's significant flow through the filter, which causes its pleats to flutter. According to Woebkenberg, the affected filters create an unequal distribution of air through the engine's mass airflow meter. This causes the meter to tell the engine control computer that too much air is reaching the engine, which causes conservative fuel and spark delivery and reduces power. But what about the 16-hp difference? AIR FLOW! 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 durability 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.

BULLSHIT ED! Clearly you don't understand how modern fuel injection systems engines work.

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.

Correct, refer to following link:

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.

It does.

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.

"My Name Is Nobody" wrote in message news:drvlj.8919$4b6.4815@trndny08...

Well I believe I have a very good understanding of how they work.

You (and your reference) are talking about changes that are outside of the bounds of what I am claiming. I am not arguing about the effect of K&N filters on maximum power. And I am not even arguing about what happens at wide open throttle on a dyno. My contention is simple - a K&N air filter should have no significant effect on the fuel economy of an otherwise unmodified engine, being driven in a normal manner, if you are comparing it to a properly maintained paper filter. The difference in flow restriction between the two is trivial under normal operation (not wide open throttle). Why do you think a K&N would provide better fuel economy? The only sensor that can even be marginally affected is the TPS and as I have repeated over and over, a TPS is not a highly precise sensor. The trivial difference in throttle opening at a steady cruise related to installing a K&N in place of a normal paper filter is to small to show up as anything more than noise to the PCM. There is plenty of adjustability built in to the PCM that will allow it to compensate for this sort of trivial change. And when it can no longer compensate, it will turn on the check engine light.

I am definitely not making any claims with regards to system that are heavily modified (different MAF, new exhaust and ESPECIALLY not changes to the PCM programming).

As for your reference - it is clearly a sales piece. The claim that the "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" has no bearing on my argument. The modifications referenced in the article included a non-Ford, large diameter, MAF This is clearly far beyond simple modifications to the air intake in front of the MAF. The PCM is designed to work with a MAF sensor that is designed to work in a certain diameter housing. Even if you used the same physical MAF sensor, placing it in a different diameter air passage changes how it responds to changes in air flow. For instance using the same MAF element in a larger bore housing would underestimate the air flow, resulting in a lean condition unless new parameters are loaded to the PCM. Clearly a modification of the PCM parameters is required by the large bore MAF used by this company. I assume you did notice that the company also sells a street setup that does not require PCM modification (yet they claim it still provides significant power increases). One further critique of people running these sort of tests - the PCM does not instantly compensate for radical changes. The fuel trim is adjusted over a reasonable period of time. While running in feed back mode, a sudden change is compensated for quickly. However, it takes longer to modify the fuel trim parameters. These parameters affect how the PCM responds to non-feedback situations (transient conditions, WOT, cold engine). After making a change to the engine (new air filter, new component, etc.), you need to operate the engine long enough for the PCM to make the necessary updates to the long and short period fuel trim parameters before making any performance measurements. But back to my original contention, a simple change in the filter is easily adjusted for my the PCM. If it can't handle the change, you will get a check engine light. If it can handle the change, the fuel economy will not be significantly affected. The PCM will adjust the fuel trim to compensate. Changing to a K&N air filter is no different than many other minor change that affects the engine parameters (change in altitude, sensor drift, normal contamination of the air filter, etc). I am not trying to argue about what may or may not happen when you make radical changes that may require the PCM to be modified.

Ed

For a modern fuel injected engine, if the filter becomes so restrictive that it will effect the fuel economy, you will get a check engine light. If the check engine light is not on, the changes are trivial enough for the PCM to compensate for.

But I am not arguing that a highly restricted air filter won't affect fuel economy. I am only arguing that a properly service air filter won't affect fuel economy to a significant degree (meaning measurable) and that a K&N will not provide a fuel economy advantage for a modern fuel injected engine compared to a properly serviced paper element. The difference between a clean K&N filter and a new paper filter is trivial. Both become more restrictive as they accumulate contaminants. Whether a particularly dirty K&N is more restrictive than a given paper filter is impossible to know. But even K&N acknowledges that a dirty K&N is more restrictive than a new paper element.

Regards,

Ed White

Where is the incentive for anyone to run such a test? Air filter manufacturers know that the results are not going to prove that their filter will improve fuel economy. It is much easier to reference unprovable, hand picked Customer testimonials, and advice left over from 50 years ago. You don't have to defend these in front of the FTC. And running such a test is not trivial. There are many factors that affect day to day fuel economy. For some factors, I am willing to make judgments based on consistent behavior and fuel economy measurements over a long period of time for some changes (tire pressure, regular vs. premium fuel, etc.). Unfortunately, air filter restriction is not one of the things I think I can personally evaluate. I posted the fuel economy of my Nissan Frontier over the last 47,000 miles in

1000 mile blocks. Even Michael Johnson wasn't able to pick out when the air filter was changed.The US EPA has a program to test fuel saving devices. No one has submitted an air filter like a K&N for evaluation.

All sort of gas saving devices are advertised based on Customer testimonials. Even K&N does this, but they are careful not to make the claim themselves in writing. Given the high cost of fuel, don't you think K&N would be willing to invest a few thousand dollars to run verifiable tests to prove their filters improve fuel economy, if they really did? Don't you think it would be worth million in sales to K&N if they could claim that the US EPA has verified that K&N air filters improve fuel economy? K&N is now running commercial touting the environmental benefits of K&N (based on reusing the filter versus replacing paper filters). Wouldn't being able to claim even a 2% fuel economy improvement be a much more powerful sales incentive? Wouldn't Ford and GM install K&N air filters as standard if they would improve fuel economy by 1% or 2%? Ford, Honda, and Toyota are all changing to 0W20 oil because it can provide a 0.5% fuel economy improvement. Ford actually sells (or sold) Foci with "lifetime" air filters. I posted a link to a Visteon paper that discussed the design of these filters. There was no problem with excess restriction in over 100,000 miles of use.

Final summary

- There is no technical reason to believe that a properly serviced K&N air filter will improve fuel economy when compared to a properly serviced paper air filter for modern fuel injected engines (modern being since 1996)

- K&N may or may not provide a power increase at wide open throttle. I am not making that argument

- If K&N air filters actually provided a fuel economy benefit they would be standard on new cars and K&N would have them evaluated by the EPA

- Customer testimonials are not verifiable (Customers have also claimed splitfire spark plugs, vortex inducers, acetone, and magnets improve fuel economy).

- Claims that a dirty air filter reduce fuel economy by up to 10% are based on carbureted engines from 40 years ago. Even then this was an extreme claim but there was a basis in fact. For a carbureted engine, a very dirty air filter acts like a choke and screws up the A/F ratio. Modern fuel injected engines are not affected in this manner. Air filter manufacturers are more than willing to allow this "old advice" to circulate. Why would they try to correct it? What filter manufacturer doesn't want to sell more filters. And interestingly, there is actually a downside to changing your filter too often. New filters don't filter as well as old filters. Even K&N makes the case that K&N filter better after they are contaminated - at which point they are as restrictive as a paper filter.

- If a dirty filter actually reduced fuel economy by a measurable amount, the check engine light would be on.

- The effect of air filter contamination is drastically different at WOT than it is at a cruise. The higher the flow rate, the greater the pressure drop for a given level of restriction. At a steady cruise the pressure drop across the air filter is trivial. If the restriction is so great as to be non-trivial at cruise, the car is going to run like s*!t when you floor it - and probably the check engine light will be set.

Ed

I posted a link to the Consumer Reports article that claimed it made no significant difference. You nit picked that because they said no significant difference. Absolute claims for fuel mileage are rarely made. No significant difference implies, no measurable difference as far as I am concerned. If you can measure the difference, is there a difference? I am certain if there was a measurable difference CR would have provided the results.

This whole thread got started because I claimed that a K&N filter would not provide a fuel economy improvement compared to a properly serviced paper filter. I stand by that claim. I've seen no data or even a good argument that refutes that claim.

Ed

No significant difference is still a difference. Only CR knows what that means. I take it as a difference they deemed worth noting.

Nor have I seen any evidence that disproves it.

Logic dictates that if a dirty filter causes a reduction in fuel mileage then the degree to which it is clogged determines the degree of the mileage reduction. The mileage reduction doesn't materialize at a defined point near the end of a filter's life span. The reduction starts to occur the minute the new filter is used and gets progressively worse.

"Michael Johnson" wrote in message news:YZidnYEMCfbNdAXanZ2dnUVZ snipped-for-privacy@giganews.com...

You are simply wrong. Why is the restriction imposed by an air filter in reasonable condition any different that the far more significant restriction imposed by the throttle plate? You seem to believe that "normal" air filters are very restrictive - they aren't. You seem to think that a reasonably well maintained air filter will force the throttle to be much further open to maintain a given speed - this is not true. You seem to think that the TPS is a very precise device that can reliably detect minor changes in the throttle position - this is not true. You seem to think that the PCM cannot adjust the fuel trim to compensate for minor changes in the air filter, sensor drift, altitude, etc. - it can. If I blind fold you and ask you to suck on a pipe, will you be able to tell where I am pinching the pipe? Your PCM can't tell the difference between the air filter restriction and the throttle plate restriction. If you are running in closed loop mode, the PCM will adjust the A/F ratio to the proper level. If things are so out of whack that the PCM can't properly adjust the A/F ratio, the check engine light will be on. The engine doesn't run in closed loop mode sometimes (wide open throttle, transient conditions, cold engine), however, the PCM includes fuel trim offsets learned during closed loop operation to compensate for changes during non-closed loop operation. Even if the TPS is affected enough so the change in signal is out of the noise range, the fuel trim will compensate. In the real world, a very dirty air filter might reduce maximum power, but as long as it is not so dirty as to turn on the check engine light, the effect on fuel economy will be trivial. An air filter maintained per the vehicle manufacturers recommendation is not likely to ever become so contaminated as to effect fuel economy by a measurable amount.

Think of the intake tract as a complete system. The amount of air that enters the engine is controlled by the cumulative restriction (air intake, air filter, piping, throttle plate, intake manifold, valves). The amount of fuel added to the air is regulated by the PCM. When it decides more air is being inducted, it increases the on time for the injectors. It determines the amount of air being inducted based on a number of factors, but mostly it uses the MAF when under steady state operation (there are limp modes that allow operation without the MAF). It adjusts the injector on time based on the response of the O2 sensors. The A/F ratio is tightly controlled. The PCM learns of changes over time and makes the necessary adjustments to maintain the proper A/F ratio. Why do you believe the PCM can't compensate for changes in the air filter? And if you agree it can adjust for changes in the A/F ratio, why would a restrictive air filter change the fuel economy.

Ed

The throttle plate is an anticipated restriction for the computer. This is why the TPS is their to communicate its position to the computer and adjust the engine's operating parameters according to the program code.

You seem to think putting words in my mouth means they are my words. Quote me where I have said normal air filters are very restrictive. In fact, I have said the opposite. This whole discussion between you and I is whether an air filter negatively impacts mileage as it gets progressively dirtier. You say it doesn't and I say it does.

.... and you seem to think mileage doesn't get progressively worse as the air filter captures more dirt but then you say a dirty filter will negatively impact gas mileage. You can't have it both ways. According to your argument the computer should compensate no matter how dirty the filter is and mileage should remain the same. Why can't the computer compensate for an extremely dirty filter?

First the computer does even see the throttle plate as a restriction. It is an air flow control device. This is why it has a TPS on it so it can predict engine operating conditions like engine load, throttle plate acceleration etc.

All this doesn't explain why a dirty filter causes a mileage reduction. Are you saying a dirty filter gets the same mileage as a pristine filter? If they don't then when exactly does the mileage drop occur. When is the "magic moment" the mileage drops? Why does the mileage drop at that point?

So they go for the short term profits and ruin the topsoil. Then have to turn around and "fix" the soil with chemical fertilizers.

I guess composting/mulching doesn't work on a large scale.

And much of this demand could be reduced if we'd get away from so damn much crappy high fructose corn syrup (HFCS) in everything.

What about the organic market? Aren't many of these guys doing it the right way and enjoying booming sales?

Seems we always do stuff on the cheap and then end up paying for it more than once. Let me explain. We over fertilize/pesticide and use poor crop rotation that ruins our soil to get cheap grain, then the grain that's produced is ruined when we turn it into garbage (HFCS) and "enriched" wheat flour, and these products are put in foods that end up ruining our health. Nice.

What are you talking about?

I say treat terrorism incidents like a crime, not a war.

Are there any parallels here with our views of native Americans a few hundred years ago?

Yes, with can't and won't the results is the same, but don't think for a minute countries can't or won't duke it out in the future over oil, water, land, etc. As the world population grows so will demand for resources, and when there isn't enough to go around for everyone...

You might want to add drinking water to the list.

It's fuel will come from new/different sources, and the timing/valves will operate more efficiently but I think the internal combustion engine is going to be around for a while.

Which is why we should be treating it like a crime and not a war.

Patrick

Exactly, but in their defense they need to do it in order to be profitable. No-till also uses heavy doses of weed killer so it isn't without issues too. Also, corn doesn't do as well as some other crops under no-till methods. I don't see much no-till on farms in Virginia or in Indiana. I'm not sure why this is so but my guess is it isn't economically viable for some reason.

Many farmers use manure on fields when and where they can. There are also many farms where I live that use treated sludge from sewage treatment plants. Most farmers leave the plant material aside from the seed portion in the fields. Some exceptions are dairy farmers that use the entire corn plant and store it in huge silos. Crop rotations work but there is so much corn grown every year that rotating all the land planted with corn isn't possible.

We are addicted to corn in multitudes of ways. Corn syrup is just one of them. I really don't eat much sugar anymore but it is a cheap sweetener and keeps food costs down.

Organic foods are selling well but they are expensive. I don't think most of us would settle for higher food prices to go organic. I'm also not sold that organic food is that much better than regular food. I think much of it is marketing hype to get us to pay more for an apple.

There are trade-offs to everything. Before we started processing foods there were many other food related diseases etc. that killed many people. Milk is a good example. Before pasteurization became common place in the 1930s milk caused sickness on a regular basis. IMO, much of the food production and delivery systems we have in place are striking a good balance for providing us quality products at reasonable prices. Just 100 years ago eating bad food and suffering sickness or death from it was not that uncommon. Today it is a rarity to hear about food related deaths or even illnesses. Especially, considering he population today compared to then.

Do you think the Taliban would have handed over Osama after 9-11? If they wouldn't then what should we do? Let him continue killing us? We fought WWII over Pearl Harbor and more people were killed on 9-11. IMO, we are not dealing with your average garden variety criminals. We are dealing with people that want to kill us on a mass scale. Reasoning with them is like Sara Conner trying to reason with a Terminator. Waiting for extradition of terrorists from Afghanistan while they plot to fly planes into the Sears Tower isn't my idea of protecting anyone.

Dragging history into the debate does nothing to keep them from killing us. Go back far enough and every group of people on the planet have killed people and taken land from someone else. It is the nature of human beings. If you are saying that we are as bad as the terrorists then we don't have much to discuss on the matter because that is just a patently untrue in TODAY'S world. What happened in the past is in the past and every race has skeletons in their closets.

There is no "duking it out" anymore. There is mutual annihilation. China can't live without us. We buy their manufacturing capability and they buy our technology and food. The same goes for India and many other countries. We can't keep six billion people alive and fight each other at the same time. The time has passed for large countries to fight war between each other. Do you think we would have invaded Iraq if they had nuclear weapons?

Shipping water from the USA to China on a mass scale will never happen. It is cheaper to run desalinization plants than to fight a war over water. Most of the world has plenty of water. Even the places that have little still get on with life. The USA has plenty of water. We just chose to live in places that don't have it, like the deserts of the Southwest.

It might but I think the only thing keeping full blown electric plug-ins is battery technology. This problem will be cracked soon. When it is look for the electric flood gates to open.

Treating it like a crime takes too long to get results and put the enemy on the defensive. The last thing I want to see is our national security put in the hands of liberal judges. I trust the military with that responsibility much more than any other entity.

You are being too simplistic, example a clean filter capable of delivering

1000 cfm new, but only 700 cfm dirty, is still quite adequate if the engine only requires 500 cfm at max rpm to start with. Air resistance is an exponential factor, it doesn't really come in to play until you get into the upper limits of your overall air flow capability. Honestly, how much time does your engine spend at 5000 rpm?

Nice theory, but it does not explain my documented 2 MPG fuel mileage increase from a simple filter change, on a 1994 SHO commuter car that I CAN SAFELY SAY NEVER HIT 5000 RPM while my wife drove it, 99.9% of it's miles.

>

Are you saying a car gets the same mileage when a filter is new compared to when it is dirty? Gas mileage decreases gradually over time and not like dropping off a cliff. Here's another one to think about.... an engine with a more efficient intake in front of the throttle body makes more horsepower than with a stock setup. That power increase happens across the rpm range. The engine making more power will get better mileage because the engine is more efficient at making that power. What difference does it make whether it is a more efficient intake or a clean verses dirty filter that causes the increase in efficiency?

"Michael Johnson" wrote in message

You just don't get it. Unless you are at wide open throttle, the restriction of a normal air filter is irrelevant for a modern fuel injected engine. Yes, certainly the engine may develop more power with a clean air filter AT WIDE OPEN THROTTLE. This is not because the engine it is more efficient, it is because you can draw more air into the engine - more air equals more power. But unless the throttle is wide open, the air filter is not the limiting factor. So unless you are driving around with your foot on the floor most of the time, the air filter restriction is not a significant factor in fuel economy. And if you are driving around with your foot on the floor most of the time, fuel economy is not something you care about.

You seem to think there is a huge difference in the pressure drop across air filters - this isn't true. At a normal cruise you only need less than 20 horsepower to go 65 mph. This is somewhere around 0.034 gallons of gasoline per minute (around 27 miles per gallon). This is around 0.21 lbs of gasoline per minute. This amount of gasoline requires around 2.9 lbs of air. This is about 26 cubic feet of air. So, when cruising you can assume that your engine only needs about 26 cfm of air. Go look at the K&N web page. They compare filter performance at 300 cfm - over ten times what is required to cruise. And even at 300 cfm the difference in pressure drop between a clean K&N and a clean paper filter is on the order of 0.03 PSI. At a 65 cruise the pressure drop across a normal filter is probably too low to be measured without very sensitive equipment. There is a reason K&N always rates the flow rate of there filters for a given pressure drop, instead of giving you a pressure drop for a given flow rate - it over hypes the difference in filters.

Discussing this subject with you is like watching a train wreck. You know there is nothing you can do about it, but you just can't turn away. I know you don't get it, I even understand why you don't get it, but I can't seem to come up with the proper way of explaining things to make you understand where your thinking is going wrong. You just can't get your thoughts around the idea that for a modern feedback controlled fuel injected engine, the PCM can adjust the fuel flow to compensate for changes in the system. Does a dirty air filter flow less air than a clean air filter, yes of course. Is the difference significant as far as fuel economy is concerned - no, not for a properly serviced air filter. We are talking about hundredths of a psi difference in pressure drop at normal cruising speeds. This difference is well within the adjustment range of any modern fuel injected engine. Heck, changes in the air filter are not close to the most significant factor that changes with time. Drift in the measuring capabilities of the MAF and TPS are more significant than the change in the pressure drop across the air filter. Until you understand that unless you are at wide open throttle, the air pressure drop across the air filter is trivial, you'll never understand why the pressure drop across the air filter is not a significant factor in determining fuel economy. An air filter dirty enough to significantly affect fuel economy should also set a fault code in the PCM and turn on the check engine light.

Ed