K&N filter

[cdixon]

My question is this. I've had K&N filters in every vehicle I've owned from 5.0 Mustangs to 4.0 Ranger 4x4 and I've not been able to notice any difference in MPG or power. Has anyone who has it on an LS V8 been able to notice any difference? I always found it kinda a pain to clean and re-oil the filters so if I'm not going to notice any difference I'll just stick with the regular air filter and change it every other oil change. Thanks.

 

[eL eS]

best pick is gained from CAI like the cones. I would bother otherwise.

 

[dertyclown]

K&N is bull :q:q:q:q. yes the filiment is thiner but it has oil on it. it is like trying to breath through a wet rage. it really makes no sence at all when you think about it. Alos any one can say that somthing will make power. dynos are BS if it is at sea levle and you move it up 10 feet you just lost 3HP.

 

[kleetus]

I tend to agree with the "clown"... I put a K&N on my 97 merq and noticed zero difference. I think a lot has to do with the amount of restriction on the head end side of the airbox. Mustangs were noted for this with that goofy air bladder thing that lived in the fender well. You took that out and put the K&N in, then the car ran better. In my 97 merq, I screwed up and didn't get the airbox back together right, and ended up leaking air around the two halves of the box. It cost me a MAF, but once I replace that, I cut a 4x6 hole in the bottom of the box, THEN it ran better, and at that point it didn't matter what filter was in it, K&N, Fram whatever.

You're probably wondering how I screwed up the airbox... sounds simple but I'm sure you noticed that once you open the damn thing, it's next to impossible to get it closed, and sealed without taking it out of the car. In my 97, it was snapped on the one side, but one of the little fingers in the corner of the box missed the receiving clip, and it allowed the top to separate a little so it would suck air across the top of the filter and not though it. I noticed more sound from WOT, so I knew something was up. It was winter, so I checked it out a day later and found salt and stuff sucked though the top of the filter and splattered against the MAF. Instant toasted MAF. It ran for a couple years like this, then it got so bad it would barely run. I did some research and answered all the questions that came up. Replaced the MAF, and it ran like new, at 120k miles. All the while the poor performance (but great mileage) was caused by the MAF which was out of cal for 3 years...

Moral of the story: Make sure that those stupid clips line up, even if you have to do it 3 or 4 times... I miss the old ones with the metal clips on all 4 sides, you knew it was sealed.

 

[Black03]

You will not notice any power difference from putting one in. There are better filters out there. It's mainly so you don't have to keep buying the cheap paper ones.

 

[jdsimons]

Well from what i have read paper cones are actually better then the k&n filters in that it cleans the air a lot better then the oiled ones. But i am guessing that they will let more air in so that could help out some, but it would be more beneficial probably to add a cone filter or cai so it can suck up a lot more air which will probably make a noticable difference from the factory location of the enclosed air filter.

 

[Styles]

So if not K&N what filter what CAI or cone would you guys recommend in your experience?

Cheers,
Eric

 

[NickLS]

There are some options... You can go to the LLSOC store and purchase either the True-Rev Induction Kit, their Stainless steel snorkel which has none of the wind-restricting baffles in it like the stock tube.. OR YOU CAN BUY BOTH!!!

http://www.llsoc.com/V2R1/CyberMerchant_public/Scripts/default.asp

I only have the KKM Filter cause I don't have the $$$ to get the tube yet...

 

[eL eS]

I spoke with Warren at Kurtz, I think i have his name right, recently. He says the tube is a superflous purchase. The only point that one can improve upon is the point of air intake.

 

[NickLS]

eL eS, why is superflous????? What about the restrictive baffles in the stock tube? The cone will allow more air to come through into the engine, but if the tube is restrictive, it will only allow so much to go through... Stupid Example: If you change the filter on the end of the straw.. no matter how big the filter is.. the straw will only allow so much air through to the engine since it's on "suction power" like the engine not under "pressure" as in a super/turbo charger....

Does this sound right?? Cause I was thinking of purchasing a tube from them... What did warren say about that?

 

[MikeB]

I also purchased just the KKZ filter and my understanding is that the stock tube flows more than the factory throtle body could ever take even at WOT.

While the factory tube could be restricting air flow, it still gives the engine all it can take without modification.

I think the filter makes a big difference on both power and sound. :L

 

[eL eS]

eL eS, why is superflous????? What about the restrictive baffles in the stock tube? The cone will allow more air to come through into the engine, but if the tube is restrictive, it will only allow so much to go through... Stupid Example: If you change the filter on the end of the straw.. no matter how big the filter is.. the straw will only allow so much air through to the engine since it's on "suction power" like the engine not under "pressure" as in a super/turbo charger....

Does this sound right?? Cause I was thinking of purchasing a tube from them... What did warren say about that?

Well for one the diameter of the throtle body remains the same. but this opinion about the tube came from the purveyor of the CAI not me. I simply called and asked some questions and he said changing the tube is simply an aesthetic improvement. I understand the argument though.

The way i understand it is that some efforts are made to create a pressure in the intake tubes by adjusting the flare of the tube; they shape it to shape the air flow. IIRC it is intended to shape the force of air being delivered into the intake maifold to improve atomization of the fuel.

I am just a newbie self learner in progress and these bits of information are just things I have recently read. I am not a seasoned tuner by any measure and have basically been asking questions and am not in the position to refute anyones claims.

The guy was kind and patient enough to educate me a little. I didnt ask well if I should buy one first or the other. In fact, I told him I that am building my intake tube and was curious about his product. First thing he said... let me ask you this then... are you doing it for looks or performance... I replied cant you have both and that is when he explained.

I got the impression that the only way changing the tube would do anything is if you went with a smaller tube and we both know that would have an negative impact.

 

[kleetus]

About the only real difference changing the factor tube out for an aftermarket unit is sound and appearance. The Factory tube has those little chambers, which are resonators at some frequency. They do nothing for or against flow. By putting a larger diameter tube on it is the same as changing the diameter of the exhaust pipe, the tone will go down.

Even if you spun the V8 at 6850 RPM, that's only about 400 CFM. When you come right down to it, that's not a lot of air. I can see and agree that the stock pipe should be able to flow that with no problems with minimal pressure drop. The air filter may very well be the problem child of this system, and to a point, more surface area on the filter is a good thing. Beyond some point, the engine just can suck enough to make any appreciable difference.

What eL eS is saying about the force of the air makes some sense, however I don't personally believe it makes any difference. (BTW: I'm not shooting at the messenger) For this to make any difference, you'd want the air to be moving as fast as possible to beat up and break up the fuel dropplets that are shot out of the injector. For a given flow rate of a gas, smaller pipe will make the velocity higher, and larger pipe will make the velocity lower. So why would changing a tube on the other side of the throttle body about 15 or 20 inches away from the injectors (as the air flies) make any difference? The intake manifolds runners are still the same size, hence the air by the injector is still going the same speed. I don't know what it looks like in our 4 valve engines, but most of the time the injector fires into the airstream, pointing right at the intake valve, so again, how will this make any difference? Gasses under a vaccum behave very differently than ones under pressure. Surface smoothness and quality make differences, albeit not greater than 10 or 15%, that's another reason why we have composite manifolds. We can design smoothness into them, and gradual sweeping bends that were not possible with older metallic casting processes.

I believe in this case it all boils down to what it looks like. Unless you built something ungodly strange, I think it would be rather tough to actually hurt the performance.

 

[eL eS]

I believe the reason they gave for shaping the tubing was to control turbulence a more predictable air flow would render a more predictable mixture. The scientific term is stoichiometry:

n.

1. Calculation of the quantities of reactants and products in a chemical reaction.
2. The quantitative relationship between reactants and products in a chemical reaction.

It is crazy stuff. I used to think of cars as linear but the more I read into the management systems I realize the are not the cars we drove in the 60's and early 70's. This is literally rocket science now.

Under turbulent conditions it is hard to predict the results of the mixture and the rate of burn so the shaping of the space or intake and intake manifold play a significant roll in calculating air and fuel.

Like I said, these are things I have read and I do not pretend for one minute to know them as fact due to my lack of experience in this field. They make sense to me as techie of multiple disciplines. Further, I welcome and encourage discussion becasue I want to know more about this field.

 

[kleetus]

I don't know about the turbulence thing, the best example I can site for this is what happens when you're at anything less than full throttle? Other than full throttle, anything ahead of that valve is meaningless in terms of turbulence. Why? Because as soon as the air hits that valve plate, stuff is flying everywhere in the wake of that obstruction. Even if that were the case, by rotating the axis that the throttle butterfly is on would have drastic effects on how the motor runs. To date, nobody on any vehicle I can think of has ever changed the orientation of the butterfly.

I guess the point I'm trying to make is by the time the air reaches the injector before it goes into the cylinder, its flow is so screwed up, it wouldn't make any noticeable difference, if even any at all.

There are plenty of things you can do to a motor that make zero difference in the real world. One that always got me was how much water a motor could take before it would try to sputter out and die. It's almost impossible on the cars with MAFs, but speed density and carbureted, it's pretty neat to see. It's also a good way to clean up a motor that was really carboned up. It's like steam cleaning for the inside of the engine, an old motor builder showed me that trick. Just make sure it's warmed up first!

 

[eL eS]

I don't know about the turbulence thing, the best example I can site for this is what happens when you're at anything less than full throttle? Other than full throttle, anything ahead of that valve is meaningless in terms of turbulence. Why? Because as soon as the air hits that valve plate, stuff is flying everywhere in the wake of that obstruction. Even if that were the case, by rotating the axis that the throttle butterfly is on would have drastic effects on how the motor runs. To date, nobody on any vehicle I can think of has ever changed the orientation of the butterfly.

I guess the point I'm trying to make is by the time the air reaches the injector before it goes into the cylinder, its flow is so screwed up, it wouldn't make any noticeable difference, if even any at all.

There are plenty of things you can do to a motor that make zero difference in the real world. One that always got me was how much water a motor could take before it would try to sputter out and die. It's almost impossible on the cars with MAFs, but speed density and carbureted, it's pretty neat to see. It's also a good way to clean up a motor that was really carboned up. It's like steam cleaning for the inside of the engine, an old motor builder showed me that trick. Just make sure it's warmed up first!

I read that about the butterfly valves orientation some where. They gave examples of how the car would react to 90 degree offset. I believe it was on one of the engine mgmt sites.

I understand how the intake valve would reshape the particle mixture but I would be inclined to think that this too has been considered in the design of each combustion cycle. To say that it is all controlled to an absolute would be ridiculous but think of how they design wings. This is about laminar flow.

check this link out for a second and just kind of speed read across.

Now keep in mind that the moving plate in the case of cars is the intake valve.

http://hyperphysics.phy-astr.gsu.edu/hbase/pfric.html

 

[SurfjaxLS]

eL eS, you're starting to sound like my AP Chem teacher.

I agree with kleetus and eL, the stock intake pipe can handle more cfm than the motor can. Unless the entire intake from INTAKE VALVES to FILTER is completely redone and made to have almost zero resistance and turbulence, there should be no noticable gains.

 

[kleetus]

Good site, some quick reference to some very fundamental equations. If you could find that link to the 90 offset, I'd like to read that one.

I wasn't talking about the intake valve, I meant the throttle butterfly itself. I agree that the location of the injector in relation to the valve makes a difference. My point of contention is the throttle valve controlling the flow in the first place. Assuming the intake tube has sufficient flow capacity to satisfy the engine, what happens in that tube doesn't make any difference. Just because there was laminar flow prior to the valve does not mean there will be laminar flow after it. It's easy to attain laminar flow at lower velocities than it is to do at higher velocities. Here's a real twist: does the air velocity speed up or slow down as the throttle valve closes from wide open?

Go the next example: you drive a boat across a calm lake. The water has zero velocity to it, meaning it's smooth as glass. Once the prop from the outboard goes through it, how long does it take for that water to go back to its original non moving state?

Example three: You have a water pipe in your house, there's a ball valve in it. You're flowing water to some device, or just out of a hose. The pipe is silent. you decide to close the valve to shut the water off. It starts to make noise. It continues to make noise until it's all but completely closed. What happened? When the water was first flowing, making no noise, we can assume that the flow was largley non turbulent or laminar in nature, right? As you put a restriction in it, the flow was then disrupted, thus causing turbulence, and destroying the laminar flow. This flow will continue to be turbulent until it has completely stopped, or at least to the point where the viscosity of the liquid can take up the energy being genereated by the water bouncing off the side of the pipe. I'm sure you have seen this to some degree somewhere.

This is my point about the throttle valve, everything is great until it starts to close and vectoraly speaking, all H e l l breaks loose on the other side! So even with the perfect pipe ahead of the throttle it make no difference, because the throttle introduces turbulence. Even if the pipe isn't perfect, the throttle still makes a mess of things.

So at best, it *might* make a difference at full throttle. Realisticly, how often are we there?

 

[eL eS]

I see your point about the flow disruption and this condition should exists at the open point as well. Open the valve slowly and you will observe the same resonanting effect. But we are looking at a system that pops oopen and closed in thousandths of seconds so these effects would be minimal but relevant.

I think the ref to the buttery fly valve offset might have been here.

http://www.emeraldm3d.com/ems.htm#index

It is pretty big write up so I could be wrong. i will look at a few other links i read JIC.

 

[Pete02LSE]

Thank Goodness

Thanks to everyone in this post that provided scientific information.

I've argued forever that the LLSOC pipe CANNOT make that much of a difference on a stock intake/heads/cammed motor. There's just no way. Just apply simple logic. Case in point...on my LS1 (99 Camaro SS) the stock MAF is good for upwards of 500 hp. Beyond that...fine...get a bit larger one. While this is not an apples to apples comparison...I'd be surprised if the stock components in the LS wouldn't support in excess of 400 hp. Anyone know if this is fact?

This is exactly why I gutted my stock air box and left the rest of the stock piping in place. I've noticed a really nice increase in top end pull...but...again...as posted above...how often are we at the big end of the speedo? This also allowed me to put $300 toward the Magnaflow that I want. Which...again...won't provide a huge power increase. I only want it for the sound.

Now...with the cracking of the LS comptuer...maybe someone will start developing headers/cams etc for the 3.9L. I sorta doubt it will ever happen...but...one can wish.

-Pete
02 LSE

 

[eL eS]

well unfortuneately I did not bookmark all the sites I read from a few days ago. So i do not have that reference to the throtle valve orientation. I will try to remember my search criteria and see if I can pull it back up through google. I contantly dump my history so that will be useless to me.

I know I read something regarding the throtle valve orientation man i could kick myself now.

 

[eL eS]

Thanks to everyone in this post that provided scientific information.

I've argued forever that the LLSOC pipe CANNOT make that much of a difference on a stock intake/heads/cammed motor. There's just no way. Just apply simple logic. Case in point...on my LS1 (99 Camaro SS) the stock MAF is good for upwards of 500 hp. Beyond that...fine...get a bit larger one. While this is not an apples to apples comparison...I'd be surprised if the stock components in the LS wouldn't support in excess of 400 hp. Anyone know if this is fact?

This is exactly why I gutted my stock air box and left the rest of the stock piping in place. I've noticed a really nice increase in top end pull...but...again...as posted above...how often are we at the big end of the speedo? This also allowed me to put $300 toward the Magnaflow that I want. Which...again...won't provide a huge power increase. I only want it for the sound.

Now...with the cracking of the LS comptuer...maybe someone will start developing headers/cams etc for the 3.9L. I sorta doubt it will ever happen...but...one can wish.

-Pete
02 LSE

this is why we gather to share and learn. If you read the llsoc, not to knock them, add for the intake I believe they mention words to the effect of whenused with the Kurts kustom CAI gains of ...hp etc.

So that got me to thinking as well. As you pointed out it would take a complete refit of the intake system and pcm programming to relize gains when it comes to increasing the tubing size.

If you wanted to put you money on performance start with the CAI and then have the pcm updated with the sct tune(s). certainly a high flow exhaust system would be more advantageous then.

 

[JohnnyBz00LS]

I'm rolling my pants up now, its getting deep in here.............

My LS ran a 15.5 bone stock, 15.1 w/ just the LLSOC/DPG CAI (w/ cone filter). Don't tell me my timeslips are all in my imagination.

Any restriction in the intake or exhaust side of the engine will hurt performance. Restrictions create a pressure gradient. Another factor most people don't seem to consider on CAI systems is acoustic tuning. While those baffles / chambers on the stock tube may not restrict gross flow very much, they are dampening / canceling out the pulse waves from the intake valve suction (that's their only reason for existance is to make it quiet). In the process of doing their job, they effectively reduce the instantanious pressure at the intake valve when it opens, resulting in less air/fuel induction on each intake stroke. This effect is also a function of RPM, since it relies on the acoustic resonance of the entire intake tract (intake manifold as well as the length of tube in front of the throttle body). The two different size "kidneys" placed at two different locations on the factory tube are designed to eliminate resonance across a broader RPM range. By eliminating those "kidneys", the intake tract is allowed to resonate, boosting instantanious pressure at the intake valves over a certain RPM range.

 

[Pete02LSE]

I'm rolling my pants up now, its getting deep in here.............

My LS ran a 15.5 bone stock, 15.1 w/ just the LLSOC/DPG CAI (w/ cone filter). Don't tell me my timeslips are all in my imagination.

So...you are saying that you picked up 4 tenths with just the LLSOC intake? What was your mph? I'm not going to call BS just yet...but...consider the following:

LS weight ~ 3700 lbs
To gain 4 tenths, you would need to pick up 20 horsepower
What were the track/weather conditions each time?
What was your 60 ft?
Did you dyno before and after the intake?

Again...I don't want to start an arguement here but...ET/horsepower comparisons are not valid until someone either:

1) Completes back to back strip runs with and without the CAI

or

2) Completes back to back dyno runs with and without the CAI

There's just no way that (all other things considered equal) the CAI provides a 20 horsepower gain over the factory intake tract. I'll be happy to eat my words at a later point if someone has either of the above. Now...I won't agrue if a combination of mods offered up a 20 horsepower gain.

One other thing to consider:

The surface area of the K&N panel and the cone are probably pretty close to the same. Because of this...using a cone is negliable. Some might argue that the 360 degree filter will help out some. Which it might. However, this setup is limited in the sense that it will suck in hot underhood air. Which will increase the temp of the intake charge...therefore decreasing horsepower. Even if you have a heat sheild...I doubt it will benefit anymore than a gutted stock airbox.

-Pete
02 LSE

 

[eL eS]

I'm rolling my pants up now, its getting deep in here.............

My LS ran a 15.5 bone stock, 15.1 w/ just the LLSOC/DPG CAI (w/ cone filter). Don't tell me my timeslips are all in my imagination.

Any restriction in the intake or exhaust side of the engine will hurt performance. Restrictions create a pressure gradient. Another factor most people don't seem to consider on CAI systems is acoustic tuning. While those baffles / chambers on the stock tube may not restrict gross flow very much, they are dampening / canceling out the pulse waves from the intake valve suction (that's their only reason for existance is to make it quiet). In the process of doing their job, they effectively reduce the instantanious pressure at the intake valve when it opens, resulting in less air/fuel induction on each intake stroke. This effect is also a function of RPM, since it relies on the acoustic resonance of the entire intake tract (intake manifold as well as the length of tube in front of the throttle body). The two different size "kidneys" placed at two different locations on the factory tube are designed to eliminate resonance across a broader RPM range. By eliminating those "kidneys", the intake tract is allowed to resonate, boosting instantanious pressure at the intake valves over a certain RPM range.

I can appreciate thier noise dampening qualities but the ID, inner diameter, of the intake tube is greater than that of the throtle body. This leave two points of impedance the filter where the air ingress' and the exhaust where it egress'.

The pressure on the front side of the throtle body will increase when air flow/velocity increase. I am ready to be told otherwise but I firmly believe that the ripples in the air tube along with the kidneys have are negligible impact on induction.

Give me some numbers a camparo of before and after and a mix of replace snorkel with stock etc...

Their website states pair it with KKM CAI and you get 10 to 15 HP and nothing about what it offers as a stand alone. what i heard from KKM is that the filter is the spot to improve unless you plan a full overhaul of induction and exhaust.