# Does your K&N Filter Actually Make Power?



## XtremeRevolution (Jan 19, 2012)

Don't answer that. I'll answer it for you. Let's begin. 

A test was done a while back comparing the net restriction between a new ACDELCO and a new K&N filter. You can review the test here:
K&N Air Filter Review - Debunking the Myths (and why OEM is better)

The net difference was 1.69 IN-H20 at 350cfm, which is equivalent to 0.61psi. To put this into perspective, the human lungs are typically capable of producing 3x that much pressure, and this is being acted against by a 1.4 liter mechanical pump with a turbo. 

Using a Widman calculator, we can estimate that at peak horsepower at 6300rpm, we are drawing 311cfm of air. 

Air flow (CFM)

Now, let's convert this to hydraulic horsepower. 311cfm equals 2326 gpm. We can then use the gallons per minute in conjunction with the pressure experienced to estimate hydraulic horsepower, which is equivalent to mechanical horsepower, using this calculator: Hydraulic Horsepower Calculator

We end up with 0.83 horsepower. 

At wide open throttle, putting down all 138hp, at 6300rpm, we can expect to gain 0.83hp, or 0.6%

Now let's compensate for filtration surface area. The OEM filter measures 10.5 x 10.28 inches, or 108 square inches of surface area. 
The K&N filter on the Typhoon intake measures 4.5" top diameter, 6.5" base diameter, and 5.5" tall, for a total of 143 square inches of surface area. This 32% increase in surface area would result in a 32% reduction in restriction, resulting in a net difference 2.69 IN-H20 at 350cfm, which is 0.97 PSI, and results in a total HP gain of 1.32hp. 

There you have it, folks. Between a bypassed intake resonator on an OEM acdelco filter, and a K&N typhoon intake can be expected approximately 1.32hp gain, give or take a few decimals.


----------



## XtremeRevolution (Jan 19, 2012)

On the topic of fuel economy, we can estimate that this car uses approximately 15hp at 2200rpm cruising in 6th gear. If we are to expect that our airflow is linear with power produced, we can reduce this to 33.8cfm. This converts to 246.86gpm and represents a 0.14hp net loss, or approximately 0.09%. 

If we were to convert a direct power to fuel economy ratio, our highway cruising fuel economy using a 40mpg baseline would increase by 0.036mpg. Keep in mind this is rather generous, as this assumes that pumping losses as a consequence of air intake restriction are directly correlated at a 1:1 ratio to changes in fuel economy. In the real world, this is not the case, but I went ahead and calculated it generously in favor of the fuel economy gain for the purpose of discussion.


----------



## chris10 (Oct 22, 2014)

Where are the butt dyno stats?......Your work means nothing without those....Haha With all kidding aside. Nice to see someone take some time and lay out the facts. I bought an Injen before diving into this site. I paid the money so keeping it on for now. The idea of it sounds awesome, but most likely just engine bling.


----------



## SportBilly (Nov 25, 2013)

I strongly believe this. I would like to get on the dyno one day and do 3 pulls. 1 with stock, 1 with "my box" and 1 with the k&n..


----------



## Vetterin (Mar 27, 2011)




----------



## _MerF_ (Mar 24, 2015)

That's a great write-up, and really liked the article referenced that showed the hard data.

I just got my shiny new Cruze yesterday and am eager to do something to her...obviously resonator delete is simple amd effective. But now, with the exception that I adore the sound of a spooling turbo, I have zero intentions of dropping $200 for an aftermarket intake.

But, just playing devil's advocate, if a car was driven in a nearly dustless environment (if pollen is excuded, which according to my sinuses right now is sorta ignorant) where the K&N would not suffer the exponential losses as quickly, it could be argued that it wouldn't be harmful or have negativr impact.

Because, and I know it's shallow and I'm ok with that, I love the sound of spool and that paper filter supposedly baffles that sound effectively.

Thoughts?


----------



## JerTM (Dec 12, 2014)

The chart for "Total dirt passed vs time" should be the strongest selling point to that article. I could't care less if a filter added 100 hp, if it passed THAT much dirt it's actively causing damage to the engine. Thanks for the info Extreme.


----------



## obermd (Mar 3, 2012)

Does adding a small amount of horsepower actually make a difference in the Cruze? The Cruze's ECU manages torque and only generates enough horsepower to provide the desired torque. Even at high altitude the my ECO MT has no problem generating the HP needed to maintain the torque the ECU is asking for.


----------



## _MerF_ (Mar 24, 2015)

Whoa. Can you link whatever source that explains how the computer manages HP depending on the torque needs? I have never heard of such a system and would be interested in the nuts and bolts of it.


----------



## XtremeRevolution (Jan 19, 2012)

obermd said:


> Does adding a small amount of horsepower actually make a difference in the Cruze? The Cruze's ECU manages torque and only generates enough horsepower to provide the desired torque. Even at high altitude the my ECO MT has no problem generating the HP needed to maintain the torque the ECU is asking for.


You can take the inverse and imply that the OEM filter causes a restriction worth 1.32hp instead. The initial purpose for all of this calculating was due to a claim a member had on our FB page that the K&N intake significantly improved his fuel economy. I set out to demonstrate how small the difference actually is under the most extreme conditions that this engine can experience in stock trim.



_MerF_ said:


> Whoa. Can you link whatever source that explains how the computer manages HP depending on the torque needs? I have never heard of such a system and would be interested in the nuts and bolts of it.


There isn't really an article that explains how, but it's a calculation based on fueling and timing. The engine can detect how much torque is being produced and limits power to 148lb-ft. You will notice that boost levels vary between winter and summer as air density changes and timing tables can be adjusted. No matter what, your power peak will always remain 148lb-ft.


----------



## _MerF_ (Mar 24, 2015)

XtremeRevolution said:


> There isn't really an article that explains how, but it's a calculation based on fueling and timing. The engine can detect how much torque is being produced and limits power to 148lb-ft. You will notice that boost levels vary between winter and summer as air density changes and timing tables can be adjusted. No matter what, your power peak will always remain 148lb-ft.


Ok, so it pulls timing/boost to sort of govern the engine. That makes more sense than the confusing first statement. Is it safe to assume that the various tunes available omit this governing?


----------



## obermd (Mar 3, 2012)

_MerF_ said:


> Ok, so it pulls timing/boost to sort of govern the engine. That makes more sense than the confusing first statement. Is it safe to assume that the various tunes available omit this governing?


This also means the car adjusts both the air and fuel being injected for combustion. If the car doesn't need the power it simply doesn't pull in as much air.


----------



## XtremeRevolution (Jan 19, 2012)

_MerF_ said:


> Ok, so it pulls timing/boost to sort of govern the engine. That makes more sense than the confusing first statement. Is it safe to assume that the various tunes available omit this governing?


One of the reasons it does this is to allow consistency based on altitude changes. In stock trim, this engine really shines as the available headroom is utilized when increasing altitude. While N/A engines will begin to fall falt on their face, the turbo and the PCM's tuning allow the vehicle to work harder to maintain that 148lb-ft when atmospheric pressure begins to drop. 

Yes, the tunes raise this limit. Depending on who you have as a tuner, most will not remove it entirely for various reasons. On my Eco MT, the limit is raised to 200lb-ft, as any higher will cause the clutch to start slipping.


----------



## Blue Angel (Feb 18, 2011)

WRT fuel economy, the lower restriction filter will actually produce 0.0% gain. Any restriction in the air filter is balanced out by changes in throttle angle, that is, the less restrictive the air filter the more restrictive the throttle body is to compensate. The air filter and throttle body are both restrictions in the intake track and they are additive. The method we use to limit torque is to restrict the air into the engine, so it doesn't matter if that restriction comes from the air filter, the plumbing, the throttle body, or some combination of the three.

K+N filter = 0.0 MPG gain.


----------



## XtremeRevolution (Jan 19, 2012)

Blue Angel said:


> WRT fuel economy, the lower restriction filter will actually produce 0.0% gain. Any restriction in the air filter is balanced out by changes in throttle angle, that is, the less restrictive the air filter the more restrictive the throttle body is to compensate. The air filter and throttle body are both restrictions in the intake track and they are additive. The method we use to limit torque is to restrict the air into the engine, so it doesn't matter if that restriction comes from the air filter, the plumbing, the throttle body, or some combination of the three.
> 
> K+N filter = 0.0 MPG gain.


Well, _theoretically_, there are pumping losses where the engine experiences a parasitic drag in order to pull air instead of it being freely available. It is force that the engine must act against, similar to piston movement friction and other drivetrain losses. It was this force that I tried to calculate and ended up with a very generous 0.036mpg, which rounds down to 0.0 MPG anyway.


----------



## CHEVYCRUZE RS (Mar 29, 2011)

I went from stock to Injen 2nd Gen. intake then back to stock, felt better stock then the injen to be honest lol ever since that day kept it stock paired with the zzp intercooler and zzp downpipes shes never been this smooth!!


----------



## brian v (Dec 25, 2011)

So like pulling off that fuzzy backing stuff off of the OEM Equipped air filter really has no influence over added horse power and Breatheability ..

Darn I should put IT back on after I clean IT off with an air compressor .
Wallah clean as new and still good for some more miles !


----------



## spacedout (Dec 7, 2010)

XtremeRevolution said:


> At wide open throttle, putting down all 138hp, at 6300rpm, we can expect to gain 0.83hp, or 0.6%


Doesn't the 1.4T only make 138HP at 4900RPM and drops off until redline? Also these motors run a bit rich stock above 5000RPM, so if one has an air intake system that is less restrictive up top(which the K&N or any aftermarket intake is), technically that increased air flow mixed with how it normally is a bit rich would increase the power more than your indicating. 

My stock 1.4T feels like it runs out of breath above 5K, riding in my buddys with a K&N intake(no tune) it pulls much stronger to redline than mine. Have been debating in installing his intake on my car to see if there is any noticeable difference.


----------



## pL2014 (Dec 29, 2013)

I had a K&N drop in panel filter on my previous car. I was never under the dilusion that it was making any extra power. For me I was under the impression it was cheaper over the life of the vehicle and was filtering approximately as well. I cleaned and oiled it every 15k and the intake was always pristine inside. Engine went 224k trouble free miles.

However, everything I've read suggests the paper filters are likely better at filtering, and the Cruze's replacement interval (even severe) is 45k (which seems high, so I'll at least be checking it more often), so I think I'll just stick with Delco paper filters especially if they last anywhere near 45k.


----------



## XtremeRevolution (Jan 19, 2012)

spacedout said:


> Doesn't the 1.4T only make 138HP at 4900RPM and drops off until redline? Also these motors run a bit rich stock above 5000RPM, so if one has an air intake system that is less restrictive up top(which the K&N or any aftermarket intake is), technically that increased air flow mixed with how it normally is a bit rich would increase the power more than your indicating.
> 
> My stock 1.4T feels like it runs out of breath above 5K, riding in my buddys with a K&N intake(no tune) it pulls much stronger to redline than mine. Have been debating in installing his intake on my car to see if there is any noticeable difference.


Placebo. Butt dyno is worthless and the car feels completely different riding as it does driving. These numbers are based on accurate calculations from actual testing. If you want me to use 4900rpm as a base line, there will be even less power. 

No, you won't be gaining any consequential amount of power due to the top end running rich. Refer back to my first post. 



pL2014 said:


> I had a K&N drop in panel filter on my previous car. I was never under the dilusion that it was making any extra power. For me I was under the impression it was cheaper over the life of the vehicle and was filtering approximately as well. I cleaned and oiled it every 15k and the intake was always pristine inside. Engine went 224k trouble free miles.
> 
> However, everything I've read suggests the paper filters are likely better at filtering, and the Cruze's replacement interval (even severe) is 45k (which seems high, so I'll at least be checking it more often), so I think I'll just stick with Delco paper filters especially if they last anywhere near 45k.


Did that previous car have a turbo that was very sensitive to contaminants?


----------



## chris10 (Oct 22, 2014)

Is it safe to say that these statements cover all intakes for the Cruze?


----------



## XtremeRevolution (Jan 19, 2012)

chris10 said:


> Is it safe to say that these statements cover all intakes for the Cruze?


The other intakes actually filter better and have closer to OEM restriction levels, so the difference is going to be even more minor.


----------



## pL2014 (Dec 29, 2013)

XtremeRevolution said:


> Did that previous car have a turbo that was very sensitive to contaminants?


No and that's a good point, it was a 2002 Intrigue 3.5L V6, naturally aspirated.


----------



## au201 (May 18, 2013)

XtremeRevolution said:


> The other intakes actually filter better and have closer to OEM restriction levels, so the difference is going to be even more minor.


So you've convinced me against K&N. I've heard the injen dry intake is safer - is that true? I would like to get it solely for increased turbo sound. I understand i won't be gaining any power. Thoughts?



Sent from AutoGuide.com Free App


----------



## cruzinred92 (Dec 4, 2013)

au201 said:


> So you've convinced me against K&N. I've heard the injen dry intake is safer - is that true? I would like to get it solely for increased turbo sound. I understand i won't be gaining any power. Thoughts?
> 
> 
> 
> Sent from AutoGuide.com Free App


He's not saying anything about the intake itself just the filter it uses. Most get the intake and get the injen filter for it. Will want to look into getting an air straightener for it tho.


----------



## au201 (May 18, 2013)

cruzinred92 said:


> He's not saying anything about the intake itself just the filter it uses. Most get the intake and get the injen filter for it. Will want to look into getting an air straightener for it tho.


Right that's what I meant. And I noticed only K&N has the heat shield...is there any way to get the intake with heat shield but not the filter? Seems if I get the whole K&N system and an injen filter it'll be over $300 


Sent from AutoGuide.com Free App


----------



## XtremeRevolution (Jan 19, 2012)

au201 said:


> Right that's what I meant. And I noticed only K&N has the heat shield...is there any way to get the intake with heat shield but not the filter? Seems if I get the whole K&N system and an injen filter it'll be over $300
> 
> 
> Sent from AutoGuide.com Free App


Get the intake used and buy an Injen filter for it. That's what I and many others did.


----------



## Blue Angel (Feb 18, 2011)

spacedout said:


> My stock 1.4T feels like it runs out of breath above 5K, riding in my buddys with a K&N intake(no tune) it pulls much stronger to redline than mine. Have been debating in installing his intake on my car to see if there is any noticeable difference.


There's always a chance that a change to the mass air sensor housing is causing turbulence and altering the _perceived_ air flow rate, which _could_ lean things out and make more power. BUT, any changes to the mass air sensor's flow characteristics usually comes with other penalties as well, like drivability issues.

I'm not saying that is what's going on with your friend's K+N, but it could be. I'm always leery of modifications made to mass air sensors... no sensor flows perfectly linear, but powertrain Engineers spend an immense amount of time characterizing the flow and map the ECU accordingly. Any changes to those characterizations will alter the air/fuel ratio, which may increase power in some places while compromising elsewhere.

Generally speaking, power in the 1.4T falls off at higher RPM due to rich A/F ratio and reduced high RPM flow due to the blockages molded into the intake manifold runners:

http://www.cruzetalk.com/forum/34-1-4l-turbo/46545-ported-intake-manfold-results.html


----------



## Blue Angel (Feb 18, 2011)

XtremeRevolution said:


> Well, _theoretically_, there are pumping losses where the engine experiences a parasitic drag in order to pull air instead of it being freely available. It is force that the engine must act against, similar to piston movement friction and other drivetrain losses. It was this force that I tried to calculate and ended up with a very generous 0.036mpg, which rounds down to 0.0 MPG anyway.


On a diesel, which has no throttle body, you would be absolutely correct.

Since a gas car regulates torque output with pumping losses (through creating manifold vacuum), a low restriction air filter only increases the engine's efficiency once the total intake system's vacuum drops to the point where the minute restriction of the air filter becomes significant; near or at WOT, where the pumping losses through the throttle body are almost nothing.

You would also be absolutely correct to argue that we're splitting hairs, and that this has no bearing on anything at all.


----------



## au201 (May 18, 2013)

XtremeRevolution said:


> Get the intake used and buy an Injen filter for it. That's what I and many others did.


Will do. Thanks! Just out of curiosity, is there a big difference between the two actual intake part? Does the heat shield really do that much? 


Sent from AutoGuide.com Free App


----------



## roadrunnerA12 (Jan 21, 2015)

Mr. Revolution, why didn't you include the surface area of the flutes in your "filtration surface area" comparison? Each flute has about 10 square inches of filtration area and each flute has two side and it looks like there are about 50 flutes in the stock filter. So that is 100 flute surface areas, each with 10 square inches and that is about 1000 square inches of "filtration surface area", no? And that is a lot more than your ~10 inch by ~10 inch measure of "filtration surface area." Nothing in your conclusion would change (except maybe another horsepower or two here or there) even though I think the total flute area of filtration surface in a K&N cone shaped filter is a lot less because the flutes are much shallower. Not too often an "engineer" can be off by a factor of 10 and nothing changes. 

Bottom line is that K&N marketing is "wicked slick" just like a lot of other "aftermarket"/"alternative market" products.


----------



## XtremeRevolution (Jan 19, 2012)

Blue Angel said:


> On a diesel, which has no throttle body, you would be absolutely correct.
> 
> Since a gas car regulates torque output with pumping losses (through creating manifold vacuum), a low restriction air filter only increases the engine's efficiency once the total intake system's vacuum drops to the point where the minute restriction of the air filter becomes significant; near or at WOT, where the pumping losses through the throttle body are almost nothing.
> 
> You would also be absolutely correct to argue that we're splitting hairs, and that this has no bearing on anything at all.


Oh absolutely. I mean the moment we are generously estimating a 0.036mpg gain, we are splitting hairs as we're discussing hundredths of a mile per gallon. 



au201 said:


> Will do. Thanks! Just out of curiosity, is there a big difference between the two actual intake part? Does the heat shield really do that much?
> 
> 
> Sent from AutoGuide.com Free App


Between the Injen and the K&N is a huge difference. I personally don't like the way the Injen filter is designed. I've owned both. It's not bad so to speak, but it doesn't look like it had much engineering thought put behind it. 



roadrunnerA12 said:


> Mr. Revolution, why didn't you include the surface area of the flutes in your "filtration surface area" comparison? Each flute has about 10 square inches of filtration area and each flute has two side and it looks like there are about 50 flutes in the stock filter. So that is 100 flute surface areas, each with 10 square inches and that is about 1000 square inches of "filtration surface area", no? And that is a lot more than your ~10 inch by ~10 inch measure of "filtration surface area." Nothing in your conclusion would change (except maybe another horsepower or two here or there) even though I think the total flute area of filtration surface in a K&N cone shaped filter is a lot less because the flutes are much shallower. Not too often an "engineer" can be off by a factor of 10 and nothing changes.
> 
> Bottom line is that K&N marketing is "wicked slick" just like a lot of other "aftermarket"/"alternative market" products.


Not only are the flutes shallower on the K&N, but they are also less dense. Comparing the K&N filter to the Injen filter (refer to my last picture), we find that same behavior, only the Injen filter is over 25% larger in flat surface area as well. 

The reason I didn't bother including that surface area is simply because I didn't feel like digging out my OEM filter, wherever it is in the garage. I wanted to present the most liberal power gains you can possibly fathom. If we were to start counting flutes and measuring their depth, we would probably discover that my measurement is much too liberal and we'd end up with an even smaller theoretical gain. 

If I have time this week, I might grab a ruler and measure the density and depth of those flutes since I have a couple of K&N intake filters sitting around. By the way, if anyone has a K&N filter they'd like to send me for the cost of shipping, I'm making lampshades out of them. About the only thing they're good for.


----------



## brian v (Dec 25, 2011)

I always wondered what you were collecting em for ! 

Me never got caught up in the hype of a better looking air cleaner and the prospects of doling out a couple of hundred bucks just to hear a turbo that is not on me engine to begin with .. OEM are like 20 bucks , cheap enough to buy twice ! 

Hey guys we have to take a collection for X​ . his wife would prefer full sized lamp shades ....................


----------



## XtremeRevolution (Jan 19, 2012)

brian v said:


> I always wondered what you were collecting em for !
> 
> Me never got caught up in the hype of a better looking air cleaner and the prospects of doling out a couple of hundred bucks just to hear a turbo that is not on me engine to begin with .. OEM are like 20 bucks , cheap enough to buy twice !
> 
> Hey guys we have to take a collection for X​ . his wife would prefer full sized lamp shades ....................


Oh these aren't for my wife, believe me. With pistons as a base, these are going to provide some ultimate man cave lighting.


----------



## cruzinred92 (Dec 4, 2013)

Blue Angel said:


> On a diesel, which has no throttle body


I'm sorry but did you mean it has no throttle body? So it runs wot all the time? Lol. Just checking but last I checked all engines have a sort of throttle body or way of limiting air. Technically it's not a gas pedal as much as a air pedal as when you press it it opens the throttle and allows more air to flow which in response sends more fuel. You all prob know this just a quick rant as I'm sitting here in the hospital with my wife and newborn and nothing to do as she's sleeping lol


----------



## obermd (Mar 3, 2012)

XtremeRevolution said:


> Well, _theoretically_, there are pumping losses where the engine experiences a parasitic drag in order to pull air instead of it being freely available. It is force that the engine must act against, similar to piston movement friction and other drivetrain losses. It was this force that I tried to calculate and ended up with a very generous 0.036mpg, which rounds down to 0.0 MPG anyway.


Most of those pumping losses will occur near the air injection into the cylinders. This is the only place where the edge turbulence from the air feed pipe/tube system is important. The air ducting cross section up to this point is huge compared to turbulence zone at the inner pipe surface. Removing restrictions by putting a more porous filter will not impact on the air flow to the combustion chambers - adding restrictions will eventually have an impact but you'd have to basically close the opening into the main air intake behind the filter. A more porous filter will also allow larger particles to make it into the combustion areas, which will lead to more surface scarring in those areas. 

Based on this alone the standard K&N filter is a non-starter. The K&N cone housing looks cool but don't put a K&N filter in there. Use a better filter. Just don't expect any performance or MPG gains from this car.


----------



## obermd (Mar 3, 2012)

cruzinred92 said:


> I'm sorry but did you mean it has no throttle body? So it runs wot all the time? Lol. Just checking but last I checked all engines have a sort of throttle body or way of limiting air. Technically it's not a gas pedal as much as a air pedal as when you press it it opens the throttle and allows more air to flow which in response sends more fuel. You all prob know this just a quick rant as I'm sitting here in the hospital with my wife and newborn and nothing to do as she's sleeping lol


Congratulations to you and your wife.


----------



## cruzen175 (Mar 13, 2015)

At times like these i refer to Mighty car mods, they did dyno test videos for both N/A engines and turbo engines.

Here's the myth busted for N/A engines: https://www.youtube.com/watch?v=xwNtjKT_1cA
Here's the one for turbo engines: https://www.youtube.com/watch?v=gCi2yo4UqPI

I don't waste money on hot air or cold air intakes, i cheaply modify the stock intakes to pull in more air and buy dry type reusable filters that are only around $30 so if i wash it once it's worth the cost.

Also oiled filters like K&N get oil on your MAF sensor, this makes it inaccurate which degrades your performance over time. This is especially true when you reapply the oil and get's really bad if you put too much on.


----------



## roadrunnerA12 (Jan 21, 2015)

cruzinred92 - what was your baby's APGAR score? By the way, diesel engines do not have a throttle plate or throttle body as noted above. Their air intake system is always "wide open". RPM increase (and thus power output) is gained by injecting more fuel. A diesel engine, given more and more fuel, will run up in RPM to the point of destruction. This happens out in the oil fields when a diesel engine driven pump gets an accidental dose of natural gas from a significant nearby leak. You hear the RPM increase way beyond normal as the engine sucks in the natural gas and adds it to the diesel fuel load, then BOOM! And then silence.


----------



## Blue Angel (Feb 18, 2011)

Like roadrunner states above, generally speaking diesels have no throttle body and control power output by regulating the fuel injected. They run at maximum lean condition at all times.


----------



## Jukebox Juliet (Apr 4, 2014)

Ok, so I've been reading through all this wonderful info. In short, I should take the K&N drop-in I just put in straight to the garbage, buy a K&N SRI and put a Injen filter on it? Or is it going to be more damaging to my car over time, as far as allowing in more dirt, etc?

I get they're mainly for looks/sound, and they do look awesome, and sound cool (at least on a manual - not sure how it would apply to my automatic) but if it's going to risk damage to the engine over time, that's my biggest concern.

The reason why I got the drop-in is b/c I was reading somewhere on here that SRI and CAI allowed more dirt into the engine, especially the K&N, and that a drop-in was better. So I was nervous to go for an SRI. Now it seems like some of you are suggesting OEM replacement is still the best option. :/ 




Sent with iLove 6.0


----------



## cruzinred92 (Dec 4, 2013)

roadrunnerA12 said:


> cruzinred92 - what was your baby's APGAR score? By the way, diesel engines do not have a throttle plate or throttle body as noted above. Their air intake system is always "wide open". RPM increase (and thus power output) is gained by injecting more fuel. A diesel engine, given more and more fuel, will run up in RPM to the point of destruction. This happens out in the oil fields when a diesel engine driven pump gets an accidental dose of natural gas from a significant nearby leak. You hear the RPM increase way beyond normal as the engine sucks in the natural gas and adds it to the diesel fuel load, then BOOM! And then silence.


Her Apgar was a 9 if I remember correctly. 



Blue Angel said:


> Like roadrunner states above, generally speaking diesels have no throttle body and control power output by regulating the fuel injected. They run at maximum lean condition at all times.


And to the both of you I wanted to say your right as well as I am actually. Well kinda lol. The new diesel engines are fitted with a butterfly valve where the throttle would be to help with egr and engine starting/stopping as well as a safety for dieseling. (Engine runaway) apologies for the mistake on my end. Said it before and I'll say it again if I'm wrong I'll be the first to admit it and this time I was. 



obermd said:


> Congratulations to you and your wife.


Thanks obermd! We just got home actually and are trying to settle in... now just to see how our 3 yo settles with her lol


----------



## ssnscruzeeco2015 (Dec 29, 2014)

My thoughts...

The world of air filters have certainly changed over the years. 

I can still remember the old big blocks with a massive round filter box on top of the carb and tiny snorkel. I think about the surface area of my little 1.4 compared to an 8 L of 30 years, Probably the same surface area for 20 % of displacement.

311 CFM to produce 138hp @6300 is not sustainable, one will either run out of road, or load, and eventually fuel. I wonder how long the full tank of fuel would last? for comparison I do have a boat that is 115 HP at 6000 and I can easily burn 10 gallons per hour at WOT 

So worst case in my mind is the 1/4 mile track. According to the folks at Wallace Racing (internet search for "horsepower and 1/4 mile times"), my "showroom stock" 3211LBs @ 138 HP would theretically pull 16.63 seconds at 81.27 MPH

The air filter modified stock would pull 16.55 Seconds @ 81.66 MPH assuming I round up the HP gain to 2 for 3211LBS @ 140 HP to cover off how the calculation is done and what seems to be very optimistic gains.

now knfilters.ca indicates a gain of 6.49 HP @ 5000 rpm so lets assume 145 @ 6300 16.36 seconds at 82.62 MPH. which is an advertised gain of 1.65% ET and a mere 1.2 % gain in MPH.

The 474 Dollar list (special price for you, right now at 288) for the K&N performance Intake Kit or the direct replacement listed at 81 (61 special) dollars will buy me alot of gas for my boat....The one and only vehicle that I do not try to hypermill, and the only one that I would consider buys a K&N filter for if i buy any.


----------



## XtremeRevolution (Jan 19, 2012)

ssnscruzeeco2015 said:


> My thoughts...
> 
> The world of air filters have certainly changed over the years.
> 
> ...


Problem is that you aren't gaining any fuel economy, you're only gaining more power, so if anything you're using more fuel. You're also significantly increasing the maintenance interval for your induction system. 

A Lexus forum tested the K&N intake for their car. Advertised 38hp. The dyno showed a 3-4hp gain. 

Does it at all surprise you that K&N acquired AEM? K&N is obsolete. A filter that provides _effectively _no power or fuel economy but requires service 3x as often and ingests ~50x more coarse dirt (and roughly 100x more fine and coarse dirt cumulative) than an OEM filter has no place in today's vehicles.


----------



## ssnscruzeeco2015 (Dec 29, 2014)

Given the parameters that I operate every in, a OEM stock replacement works for me. however....

Disclaimer, this is not me being an advocate for K&N(AEM), FRAM or Fleetguard (Cummins) they just happen to have the information online that I was looking for.



> Does it at all surprise you that K&N acquired AEM? K&N is obsolete. A filter that provides _effectively no power or fuel economy but requires service 3x as often and ingests ~50x more coarse dirt (and roughly 100x more fine and coarse dirt cumulative) than an OEM filter has no place in today's vehicles._


Now the above quote does highlight a weakness in K&N specifications and could put at risk the real reason why the filters are there. 

The folks at K&N do highlight that particles between 10 and 20 microns causes the most engine wear and that they indicate that their filters have and overall efficiency of 96 to 99% based on ISO 5011 test procedure. They aim their design at 98%. which also means that a 98% efficient filter that stopped 98 grams of dirt also allowed 2 grams of dirt though to the engine induction and exhaust systems that can damage valves, piston rings, cylinder walls, then out the exhaust system getting caught in the catalytic converter or pass into the lubrication system and circulate through out that system until the almighty oil filter picks it up or it settles on the bottom of the pan to turn into sludge.

The filter from K&N apparently showed efficiency between 97.76 to 98.89% I am still looking for specifications supplied by other filter manufacturers.

It is clear that K&N markets their filters towards added HP and acceleration, Performance measurements of engines that are often bits of mangled metal quickly for other reasons. no 160 000 km mechanical warranty there. I am not going to go down the million mile warranty bit from K&N.

Fleetguard markets the flip-side of filter marketing and talk about quality filtration and they indicate that 1 gram per HP of dirt (138 grams) could "destroy my engine" and that my little car engine could inhale 1.75 Kgs of dirt per 100 000 kms.

In theory I want that filter starting efficient to be better than 97.5% just to prevent the engine from be destroyed within 300 000 kms.

The service interval for GM is every 72 000 kms replacement or every 4 years whichever happens first.

K&N recommends cleaning every 50 000 km? Fram indicates replacing every 12 000 miles or 19 000 kms? ? depending on environments?

So how good is the OEM filter? is it better than K&N? or are 2 new GM filters just good enough to get GM through the 160 000 Km warranty?

IF the folks at ACDelco, Fram, or the like were so bold to provide specifications it would be great. But I did find this... which will put a smile on xtremerevolution. The folks a GMtruckcentral published a test on a spectrum of filters back a couple of years ago using an engine from a pickup, but used a 5 micron contaminate which is smaller that what I would hope for a test. The results support my suspicions that K&N and other foam filters are great at airflow but suck a filtering it. no pun intended, and that Amsoil is #1.

Air Filter Comparison Study - GM Truck Central


References

K&N Air Filter Facts You Should Know

http://www.knfilters.com/dynocharts/33-2966.pdf

K&N Air Filter Efficiency Testing

https://www.cumminsfiltration.ca/pdfs/product_lit/americas_brochures/LT32599_05_select.pdf

https://www.cumminsfiltration.ca/pdfs/product_lit/americas_brochures/LT36178-GB.pdf

http://www.chevrolet.com/content/da...nd_Videos/02_pdf/2015-cruze-owners-manual.pdf

Tough Guard Air Filter | FRAM


----------



## XtremeRevolution (Jan 19, 2012)

ssnscruzeeco2015 said:


> Given the parameters that I operate every in, a OEM stock replacement works for me. however....
> 
> Disclaimer, this is not me being an advocate for K&N(AEM), FRAM or Fleetguard (Cummins) they just happen to have the information online that I was looking for.
> 
> ...


Nice to see someone do some research on this; I thought I was the only one. Haha. 

There are two nasty effects of K&N filters. The first is the terrible filtration efficiency, and the second is that, despite the terrible filtration efficiency, the filter also loads to the point of restriction sooner than cellulose filters. The environments where such a filter are actually suitable are very small.

The AMSOIL EA filters really are fantastic. The technology was actually taken from Donaldson's EA nanofiber filtration media, which was developed for use in the M1 Abrams tank in desert conditions. The reason was actually not for filtration efficiency, but for capacity. Not only does the EA filter provide the best filtration efficiency, but it also provides the highest capacity. In essence, the exact opposite of K&N filters. 

I was disappointed to hear that AMSOIL discontinued their EA filter lineup for OEMs. There were just far too many different filter sizes to make a filter for and a $47.50 air filter that promises no performance gains was a bit of a tough sell for some. I bought one for both of my other vehicles when I heard they were being discontinued. 

In a stroke of irony, I find that the best "performance" intake for this vehicle includes the K&N intake with an Injen EA air filter, which is 25% larger in filtration surface area and is made by AMSOIL using the same media that was tested in that report above. 

Thank you for posting the resources.


----------



## ehagendorff (Mar 7, 2014)

Yeah but...it makes the car sounds so cool! It's the only way to hear the turbo!


----------



## JerTM (Dec 12, 2014)

I had a 2010 G6 come into the shop yesterday for an oil change with a drop in K&N. It had 82k miles on the 2.4L ecotec. I drained the oil, didn't notice anything abnormal. She was still about 20% on the OLM. After removing the filter I noticed a lot of silver metallic coming from the engine side of the filter. The car was well maintained and clean with regular oil changes at my dealership. The only way I can account for the metal was the K&N filter.


----------



## obermd (Mar 3, 2012)

JerTM said:


> I had a 2010 G6 come into the shop yesterday for an oil change with a drop in K&N. It had 82k miles on the 2.4L ecotec. I drained the oil, didn't notice anything abnormal. She was still about 20% on the OLM. After removing the filter I noticed a lot of silver metallic coming from the engine side of the filter. The car was well maintained and clean with regular oil changes at my dealership. The only way I can account for the metal was the K&N filter.


Look at the scoring on the inner parts of that image. Something's scrubbing that engine.


----------



## Blue Angel (Feb 18, 2011)

Just to be a total tool, I will answer the original question...

No air filter makes power, some just waste a little less.


----------



## _MerF_ (Mar 24, 2015)

JerTM said:


> The only way I can account for the metal was the K&N filter.


That is a bold assumption there. Way too many other variables to account for before jumping right to the air filter!


----------

