K&N /Green cotton air filters...are they worth it?
Discussion
Hi there was looking at getting one of these K&N filters and searched on 33-2784, is this the part number when sourcing one? Secondly do you guys notice a difference in performance with having more air flow up to 30-40% as they may claim? I only replaced my filter about six months ago with a stock one and am reluctant to swap it with something that goes unoticed.
Whats your opinions?
Whats your opinions?
Kylie,
They definitely release a few (read 3-4) more ponys. But, it's no magic.
These filters pass more air by having filter media with larger openings. The downside... more dirt can and does pass through them which can be detrimental.
I am as yet unconvinced that the slight HP gains are worth it despite claims that oil is used to hydrostatically trap these dirt particles. If that were true, they would need cleaning much more often or will clog actually resulting in poorer performance. Plus, cleaning and oiling can be a messy chore.
They were originally concieved for racers who tear down and rebuild their engines so frequently as to make worrying about the long term effects of wear irrelevant, but to whom an additional 3-4 HP could make a difference in a race.
I have never seen the benefit of using them, although if you were dilligent about keeping them clean, I suppose they may save a few bucks and provide a placebic comfort that your engine, empirically anyway, makes more HP. Happy Motoring!... Jim'85TE
They definitely release a few (read 3-4) more ponys. But, it's no magic.
These filters pass more air by having filter media with larger openings. The downside... more dirt can and does pass through them which can be detrimental.
I am as yet unconvinced that the slight HP gains are worth it despite claims that oil is used to hydrostatically trap these dirt particles. If that were true, they would need cleaning much more often or will clog actually resulting in poorer performance. Plus, cleaning and oiling can be a messy chore.
They were originally concieved for racers who tear down and rebuild their engines so frequently as to make worrying about the long term effects of wear irrelevant, but to whom an additional 3-4 HP could make a difference in a race.
I have never seen the benefit of using them, although if you were dilligent about keeping them clean, I suppose they may save a few bucks and provide a placebic comfort that your engine, empirically anyway, makes more HP. Happy Motoring!... Jim'85TE
I have one on my 89 and as the other gent stated the amount of h.p. gain is barely noticeable with the air filter being the only mod. To get the most benefit from the addition keep in mind that the engine is basically a pump. If you de-restrict air-flow on the intake end, you need to de-restrict on the exhaust as well. This will get you the additional ponies you're looking for. I have an equal passion for motorcycles and that is the common quick power gain method. With just the addition of the filter I did notice a better gas mileage number.
I understand that an induction mod can only bring in the air if the other end can shed it, otherwise it would be like trying to blow into a glass bottle,right?
Can you then,fit a straight through exhaust or cat by-pass pipe without changing the induction/management to compensate for the greater flow?
I figure this like trying to suck air from the bottle.
Sorry Kylie if this detracts from your question,but i think any replies will be of help and stay on topic.
PAUL C
Can you then,fit a straight through exhaust or cat by-pass pipe without changing the induction/management to compensate for the greater flow?
I figure this like trying to suck air from the bottle.
Sorry Kylie if this detracts from your question,but i think any replies will be of help and stay on topic.
PAUL C
Something worth considering on a turbo motor.. imagine the air filter (for this example, a restrictive one) causes a pressure drop in flow, say 0.5psi across its element. Now, your turbo, which is set to pump say 9psi into the system, will only be able to deliver 8.5 to the engine because it has to overcome the 0.5psi filter element loss. Add to this the fact that the charge temperature at 8.5 psi delivery will be the same as if it were delivering 9psi thru a free flow filter. My guess is that you will experience some loss of performance.
I am unsure just how much energy loss potential there is for the filters or intake system, but the logic is there.
I would think the same logic would go for exhaust restrictions downstream of the turbo, reduce the back pressure, and increase the turbo potential.
Thats just my opinion.. I could be wrong
I am unsure just how much energy loss potential there is for the filters or intake system, but the logic is there.
I would think the same logic would go for exhaust restrictions downstream of the turbo, reduce the back pressure, and increase the turbo potential.
Thats just my opinion.. I could be wrong
We have had a Ford Falcon 250CID (4.1 ltr) in the family for 23 years. For the first few I noticed the fuel consumption increasing markedly 22mpg to 12 mpg after about 6 months. A new paper filter would cure this. On changing to the K&N this would extend out to 3 years. The paper filter was effectively blocked with all the pleats visible whereas the K&N would keep working until the pleats were nearly full, showing it was stopping the dust. (we do a lot of driving on dusty unsealed roads)
I clean and reoil filters annually.
The car was reconditioned at that time (15 years ago) at 8000 miles per year and hasn't been touched since.
We use K&N on all the cars in the family. To me the amount of dust they stop is proof of their effectiveness and better fuel consumption is surely an indication of better breathing.
I clean and reoil filters annually.
The car was reconditioned at that time (15 years ago) at 8000 miles per year and hasn't been touched since.
We use K&N on all the cars in the family. To me the amount of dust they stop is proof of their effectiveness and better fuel consumption is surely an indication of better breathing.
Kylie,
I posted the same question about a year ago and I think Jim right. In fact he posted almost the exact same reply. However, Iam a little like yourself and wanted the ever so slight power increase, so I bought one. I did notice that you get a sucking sound from just behind the driver's side when you put your foot down. My other paper filter needed changing anyway and when I put the K&N in, it did seem more responsive. This was partly due to my old filter being clogged up anyway.
At the end of the day, it's all about personal preference.
Cheers,
Dave Walters
I posted the same question about a year ago and I think Jim right. In fact he posted almost the exact same reply. However, Iam a little like yourself and wanted the ever so slight power increase, so I bought one. I did notice that you get a sucking sound from just behind the driver's side when you put your foot down. My other paper filter needed changing anyway and when I put the K&N in, it did seem more responsive. This was partly due to my old filter being clogged up anyway.
At the end of the day, it's all about personal preference.
Cheers,
Dave Walters
Heres some interesting tests on various air filters by a Miata owner
www.bobistheoilguy.com/airfilter/airtest1.htm
www.bobistheoilguy.com/airfilter/airtest1.htm
moriarty said:
Heres some interesting tests on various air filters by a Miata owner
<a href="http://www.bobistheoilguy.com/airfilter/airtest1.htm">www.bobistheoilguy.com/airfilter/airtest1.htm</a>
Hi,
Very interesting. Although the degree of accuracy can be questioned, ie. the actual numbers, the validity of the test seems all there.
It pretty much validates what I have said. Gauze and foam filters do flow better, but at the expense of poorer filtration. As I said, not an agreeable trade-off for me.
Another point, namely that the slight power increases are hardly distinguishable without a Dyno and mostly placebic. Especially when you consider that the power is delivered on a curve and that volumetric efficiencies between the two types of filters are near equal until you go on boost, so in the lower RPM ranges no power increase is to be had, only in a very narrow band. But, the poorer filtration is omni present.
Add to that the likely fact that, on a street car, you spend probably <1% of the car's life in this max power range, I don't feel the time, expense, maintenance and minimal power gains are worth switching to the gauze/foam type filter.
It seems somewhat ironic that so many are near maniacal about the quality of oil used and frequent oil changes to limit internal dirt in the engine only to leave the door open to acquiring external (and certainly more harmful) dirt through the airbox. Still, as has been previously mentioned, it is a matter of personal preference. Just make sure you fully glean and understand the facts through all the hype before you decide. Happy Motoring!...Jim'85TE
>> Edited by lotusguy on Wednesday 21st January 14:54
red_devil said:
I think most of us will not drive esprit on the same track as 4X4 does. Dirt is not a serious concern for esprit.
Hi,
Not true at all! Unlike the dirt which accumulates in the engine oil which is primarily made up of much softer combustion byproducts, since this is essentially a closed system, the dirt which one picks up through the air induction is much harder.
In addition to silicates from sand/dirt, there is a significant amount of ferrous particles, primarily rail dust (which is also the main contaminate found on your paint). These particles do not settle out as do much of the dirt in the oil, rather, they are deposited directly in the path of the reciprocating gear.
Plus, while they are very small (often <30 microns), I read an analysis which stated that the weight of these particles can accumulate to as much as .2 lb. as measured by the weight of a paper air filter before and after 10k miles in service. That is a lot of junk to be cycling through the system. Even a paper filter doesn't eliminate all this dirt, but it does eliminate significantly more than the gauze/foam types. Happy Motoring!... Jim'85TE
Also, it depends where you live. I live on the west coast of Aust. All the winds from the Indian ocean bring in all the sand, and Perth where I live is supposed to be the second windiest city in the world.
Sand is a huge problem - if the pool cleaner is not running for one night, the pool bottom is covered in sand.
In environments like these, definetely don't use a K&N.
Sand is a huge problem - if the pool cleaner is not running for one night, the pool bottom is covered in sand.
In environments like these, definetely don't use a K&N.
what you all seem to miss is that air flows through the combustion chamber.. not a dead end there
even if a grain of sand enters past the intake valve, it will surely be expelled on the exhaust stroke.
and fine dust that passes any filter will burn ( yea-remember there is some combustion going on in there) and turn to powdery ash..
There is very painful mental images of dirt entering the motor and causing wear, but in reality, it does little harm.
the wear of the cylinder is due mostly to the steel rings rubbing on the cylinder sleeve. and any lack of lubrication will speed things up.
If you were driving a car where the engine lasts 300 000 miles I would worry about the slight issue of dirt, but how many esprit engines last over 100000 miles???
It is a non-issue guys, a fly screen will brobably suffice for us who drive on nice days only. if you are on a farm road with dust flying, how much do you care about the car anyway??
I also know that the engine computer injects fuel based mostly on the measured amount of air entering the engine, so with a clogged filter it is like having the throttle partly closed. There should be no effect on fuel consumption. It is not like the carburetor days....
I think the sound of the K&N and the overall savings of money are the best reasons to do it. performance is way to subjective at that level.
Bruce...
ps
hehe my car came with the K&N and I will keep it there.
I put one in my BMWs cause the dealer was charging 50 bucks for the paper ones....
even if a grain of sand enters past the intake valve, it will surely be expelled on the exhaust stroke.
and fine dust that passes any filter will burn ( yea-remember there is some combustion going on in there) and turn to powdery ash..
There is very painful mental images of dirt entering the motor and causing wear, but in reality, it does little harm.
the wear of the cylinder is due mostly to the steel rings rubbing on the cylinder sleeve. and any lack of lubrication will speed things up.
If you were driving a car where the engine lasts 300 000 miles I would worry about the slight issue of dirt, but how many esprit engines last over 100000 miles???
It is a non-issue guys, a fly screen will brobably suffice for us who drive on nice days only. if you are on a farm road with dust flying, how much do you care about the car anyway??
I also know that the engine computer injects fuel based mostly on the measured amount of air entering the engine, so with a clogged filter it is like having the throttle partly closed. There should be no effect on fuel consumption. It is not like the carburetor days....
I think the sound of the K&N and the overall savings of money are the best reasons to do it. performance is way to subjective at that level.
Bruce...
ps
hehe my car came with the K&N and I will keep it there.
I put one in my BMWs cause the dealer was charging 50 bucks for the paper ones....
Hi, I just put it in, its the wobbly bendy one Talk about tricky, the rubber seal that you re-use for sealing off just wouldn't sit still. I didn't think I could get the rubber seal on? But I manganed to get it on no worries and has a good fit. The K&N is pre-lubed and still got plenty of oil on the rubber seal, so will fire it up tom after work for a run to listen to that nice waste gate flutter sounding sweeter 
.
I noticed there was excess oil sitting in the bottom of the air intake unit that holds the filter and am sure its not from what I put there. Do you think it could be spitting oil back from my turbo? Seems alot, I couldn't quite get my hand down the air pipe to feel for anything unusual.
Oh dear what have I started
Talk about tricky, the rubber seal that you re-use for sealing off just wouldn't sit still. I didn't think I could get the rubber seal on? But I manganed to get it on no worries and has a good fit. The K&N is pre-lubed and still got plenty of oil on the rubber seal, so will fire it up tom after work for a run to listen to that nice waste gate flutter sounding sweeter . I noticed there was excess oil sitting in the bottom of the air intake unit that holds the filter and am sure its not from what I put there. Do you think it could be spitting oil back from my turbo? Seems alot, I couldn't quite get my hand down the air pipe to feel for anything unusual.
Oh dear what have I started
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