Any thoughts on K&N Filter Kits?

[JeffM]

There was a discussion alittle while ago, and the K&N filters were not the #1 filters.

[LT22]

Yeah Wix is supposedly the number one filter company, nascar uses it and its suppose to be good since nascar uses it bunch of bull, this is just a scam trying to rob your money. I work at a mechanic and the best filters hands down are orignal filters for example i own a Mercedes-Benz best filter for it Mercedes filter. They cost a lot more than aftermarket filters but they are the best, why because the dealers make it especially for that car, aftermarket products are only good for upgrades. for example if you buy a new intake of course your going to use a filter from the brand of the intake. Orignal parts the best. More money though.

[Don]

Originally posted by LT22
First of all a new intake gives you more hp and a slight better mileage, but if you want more mileage you buy aftermarket exhaust, this also gives you more hp and mileage. Factory standard parts which are called orignal parts, such as intakes and exhaust system are both air stricted when you buy aftermarket products they simple free the restriction,

If you want to go into this kind of detail (no pun intended) then a large portion of aftermarket/bolt on parts intended for HP increases have another side to the coin...MPG increases.

Like LT22 mentioned, a free flowing exhaust along with an intake makes it easier for the engine to breathe. Easier breathing = more efficiency= more HP & with a light foot = more MPG.

An underdrive pulley (system) has a dual effect: It slows down the rate the accessories (alt/AC/PS spin at) decreasing wear on these parts, increasing their lifespan at the same time it lessens the amount of energy the engine has to use to turn these accessories which means more power available to the wheels which in turn means under light driving, the engine is already working less so less fuel is required to do the same work as before...more MPG *Side Note* underdrive pulleys do not adversely affect accessory performance (alt output etc) so unless you have some MONSTER stereo system that draws a lot of amps, you shouldn' even notice.

The thing that changes these bolt-ons from performance (HP) parts to economy (MPG) parts is your right foot. Heavy foot = more power, light foot = more MPG

[mirrorfinishman]

1- How often do these types of filters need to be cleaned?

2- What are the negative effects when they are not maintained properly?

[Superior Shine]

So to sum it up, never mind the $50 air filter. You need a new intake, exhaust and supercharger!!! LOL!


THESE GUYS ARE CAR CRAZY!!!!!!!!!!!!!!!!!!!!

[sean]

Originally posted by mirrorfinishman
1- How often do these types of filters need to be cleaned?

2- What are the negative effects when they are not maintained properly?

1. K&N says that it needs to be cleaned when theres a large amount of dirt built up which is about 30,000 - 50,000 miles. They recommend checking the filter once a year.

2. As for maintaining it, they're very low maintainace. However, if you don't clean it, your car wont perform as well, lower hp and milage. Just imagine running a few miles with a clogged gas mask.

[Beercan31]

I have posted a similar post on the Two Guys Garage Forum

here's what I posted:
I have a 2003 dodge Dakota 4.7 4x4 club cab
my average mpg is 15.2-16.2
performance is real good
now gentleman get your thinking caps and calculators out because I can not figure it out.
(the fear of the unknown)

The mods I would like to do are: (upon request I will give you a address for donations)
k & n cold air kit 12 HP/15 ft/lbs Torque $199.00
throttle body spacer 5-8 HP/13 ft/lbs Torque $108.29
headers 15-20 HP/26 ft/lbs Torque $686.99
cat back system w/ duel exhaust tips. 10-15 HP/30 ft lbs Torque $355.00

Magnum(R) 4.7L V8 engine produces 230 horsepower at 4,600 RPM and 290 pounds-feet of torque at 3,600 RPM.

now!! if my math is correct my horse power rating would be
279hp with
374ft/lbs torque
ya following me so far?

with out going in to driving habits will this change fuel average?
Better or worse? and why please.

As i see it all of these will allow the motor to breath, breathing is good, but with fuel prices going through the roof I can not justify these changes if My fuel average goes through the roof. I know for fact the most use full change would be the throttle body spacer I will explain if need, than the headers, cat back, cold air kit.

Thank you

and here was there response:

Danny
don't confuse performance with fuel economy, for the most part you regulate fuel economy with the right foot.

thecarguy
All the bolt on WILL NOT add as much HP as they claim. Sure there will be an increase, buy you wont have 279. And as Danny said fuel economy is regulated by your foot. IMO if these mods really did add economy (just as some people believe synthetic oil adds fuel economy) they would come from the factory that way as they are shooting for best mix of economy and performance

Hope this Helps you in your deciding factor.

[Aurora40]

Originally posted by Don
All other things being equal, extra oxygen in the mix means a more complete burn of the intake charge which in turn = more efficient fuel use = less fuel required to do the same amount of work.

Granted this is very slight, we're not talking huge numbers here, but I personally have picked up roughly 2 mpg in my car (2.2l 16v 4 cyl) If I could put my right foot on a weight reduction plan, the increase could be a few mpg more

**edited to add: Many engine control computers monitor the throttle position (via sensor) to determine how much fuel to send to the engine. Even the ones that use an air-flow meter are still biased to run slightly rich (rich is safe...less chance of detonation-engine damage) so a simple bolt on like a free-flow filter or Cold Air Intake will not even be visible to a throttle position sensor which means the same amount of fuel is delivered but with more O2 and the F/F filter doesn't increase the flow to a point outside of an airflow sensor equipped vehicle's *range* of *normal* airflow that would trigger a fuel increase. and a cold air intake (not more air, just colder/denser/more oxygen) doesn't affect the readings of either system.

No offense, but I don't buy any of this at all. Modern cars are aware of the temperature, density, pressure, and all sorts of things about incoming air. If it is denser, cooler, etc, the ECM will know it and can adjust the fuel delivery to compensate. In any modern stockish car, the fuel delivered per amount of oxygen is pretty well regulated and controlled. More air = more fuel = more power. When you are cruising, you do not need as much power, thus you limit the air and fuel allowed.

The ways an engine can gain efficiency is if the pumping in of air is made more efficient. If there is less pressure drop, then the piston on the intake stroke has to consume less energy working against vacuum. However, this is irrelevant in part-throttle because the throttle plate intentionally creates vacuum and restriction to limit the power the engine makes. This would only matter on wide-open-throttle, and would also allow a greater pressure of air to enter the cylinder, thus allowing more fuel and more power.

I do believe an exhaust can improve fuel economy because each piston has to force out the exhaust. The more pressure it has to push against (back-pressure), the more energy from another cylinder on the power stroke is required. The higher the pressures, the harder it is to push against, and the more energy required. This is wasted energy to push out exhaust that could have been used to turn the crank/move the vehicle. So the easier you make it for exhaust to flow out, the less power is sapped on the exhaust stroke. There is no artificial increasing of backpressure like there is of intake vacuum by a throttlebody. So any gains are always present.

While I think performance air filters can make power, I fail to see how they can improve economy. It just doesn't add up with how an engine operates.

As an aside, another source of efficiency can come with how well air flows on the inside of the motor. Each time a piston moves, it's not only moving air through valves, but it is displacing air inside the block. The better flow there is between cylinders inside the block, the less energy is wasted there pumping air around. Of course this isn't bolt-on or easy to do, but can help if you have a motor apart anyway or are building up a performance motor.

Edit: This is just my opinion, though. It's not like I'm some expert on IC engines.

[stealth]

Along w/detailing I do performance tuning. The K&N units as well as other similar units produce some results but shop price @ Summit Racing,Jegs or K&N direct. Only certain resellers get them so they're not always readily accessible. To achieve a noticeable performance gain I usually recommend a low restriction cat conv & matching exhaust system usually in a larger diameter but not so large as to eliminate back pressure completely. W/O getting techy think of how your lungs work & let that motor breathe. Enjoy the ride & the sounds,have fun!

[gb387]

Originally posted by sean
What kind of car do you want to install it on? These are easy, quick ways to add 10-20 hp.

This would go on a 03 Ford Lightning

[Don]

Originally posted by Aurora40
No offense, but I don't buy any of this at all. Modern cars are aware of the temperature, density, pressure, and all sorts of things about incoming air. If it is denser, cooler, etc, the ECM will know it and can adjust the fuel delivery to compensate. In any modern stockish car, the fuel delivered per amount of oxygen is pretty well regulated and controlled. More air = more fuel = more power. When you are cruising, you do not need as much power, thus you limit the air and fuel allowed.

The ways an engine can gain efficiency is if the pumping in of air is made more efficient. If there is less pressure drop, then the piston on the intake stroke has to consume less energy working against vacuum. However, this is irrelevant in part-throttle because the throttle plate intentionally creates vacuum and restriction to limit the power the engine makes. This would only matter on wide-open-throttle, and would also allow a greater pressure of air to enter the cylinder, thus allowing more fuel and more power.

I do believe an exhaust can improve fuel economy because each piston has to force out the exhaust. The more pressure it has to push against (back-pressure), the more energy from another cylinder on the power stroke is required. The higher the pressures, the harder it is to push against, and the more energy required. This is wasted energy to push out exhaust that could have been used to turn the crank/move the vehicle. So the easier you make it for exhaust to flow out, the less power is sapped on the exhaust stroke. There is no artificial increasing of backpressure like there is of intake vacuum by a throttlebody. So any gains are always present.

While I think performance air filters can make power, I fail to see how they can improve economy. It just doesn't add up with how an engine operates.

As an aside, another source of efficiency can come with how well air flows on the inside of the motor. Each time a piston moves, it's not only moving air through valves, but it is displacing air inside the block. The better flow there is between cylinders inside the block, the less energy is wasted there pumping air around. Of course this isn't bolt-on or easy to do, but can help if you have a motor apart anyway or are building up a performance motor.

Edit: This is just my opinion, though. It's not like I'm some expert on IC engines.

Disagreement is good, it leads to discussion (at least if the participants don't get stupid (take stuff personally), which in turn leads to knowledge gained.

You're correct about the exhaust, backpressure is bad, free-flow is good. The same with the intake, but instead of pushing air out think about pulling it in. when the air is drawn into the engine, it has to pass through the filter.

Stock filters VS High-flow filters are like a person trying to breathe through denim (try going for a jog with mask made from a leg from a pair of jeans) VS cotton gauze. It's much easier to breathe through the gauze, which means the engine doesn't have to work as hard to pull the air into the cylinder...less energy to do the same job = energy (fuel) saved.

You make a similar statement, look at the part of your quote where I made the text red.

Sport Compact Car did a project on a Nissan 200SX with many of the above (throughout the thread) it made significantly more power they also discovered the car was now getting 40 mpg because of the "performance" modifications.

I'll go look for the article.

[Don]

Originally posted by Beercan31
IMO if these mods really did add economy (just as some people believe synthetic oil adds fuel economy) they would come from the factory that way as they are shooting for best mix of economy and performance

Don't count on it...most manufacturers are look at cost effectiveness, why put a $40 air filter in a car when they can use a $3 one and not have to add the extra cost to the MSRP of the car to make up for the more expensive part?

[Aurora40]

Originally posted by Don
Disagreement is good, it leads to discussion (at least if the participants don't get stupid (take stuff personally), which in turn leads to knowledge gained.

You're correct about the exhaust, backpressure is bad, free-flow is good. The same with the intake, but instead of pushing air out think about pulling it in. when the air is drawn into the engine, it has to pass through the filter.

Stock filters VS High-flow filters are like a person trying to breathe through denim (try going for a jog with mask made from a leg from a pair of jeans) VS cotton gauze. It's much easier to breathe through the gauze, which means the engine doesn't have to work as hard to pull the air into the cylinder...less energy to do the same job = energy (fuel) saved.

You make a similar statement, look at the part of your quote where I made the text red.

Sport Compact Car did a project on a Nissan 200SX with many of the above (throughout the thread) it made significantly more power they also discovered the car was now getting 40 mpg because of the "performance" modifications.

I'll go look for the article.

Hey Don,

I agree with the similar analogy. It's harder to pull air through, and there is more pressure drop. Of course, vacuum can only be so much in earth's atmosphere, where pressure can be quite high. So an exhaust can be a lot more punishing if it is restrictive...

But anyway, here is where I see that analogy fall apart. At wide-open-throttle, you are right on. Less restriction, and also less pressure drop means more air in the cylinder. But at part-throttle, you are creating vacuum with the throttle-blade. There will always be a restriction, as this is what prevents the motor from cranking out full-power all the time. So a freer-flowing air filter won't do anything, as you will create the same amount of vacuum and allow the same amount of air in via the throttle-blade while cruising as you always did. And the ECM will mix in the same amount of fuel with that air.

There is no similar analogy to the exhaust because you never intentionally induce more pressure via throttle blade (with rare exception) to choke the engine.

[Beercan31]

Don I shot my self in the foot on that one........stepping out

[Aurora40]

Originally posted by Don
Don't count on it...most manufacturers are look at cost effectiveness, why put a $40 air filter in a car when they can use a $3 one and not have to add the extra cost to the MSRP of the car to make up for the more expensive part?

In addition to this cost, what manufacturer would feel comfortable telling customers to wash their filters properly and re-oil them. There would be a lot more liability and warranty concerns than with an idiot-proof paper filter.

There have been some examples of cotton gauze filters on hi-po cars. Vipers got them on some higher-output models that claimed about 10 more hp.