K&N Filter - Placebo?
Discussion
Vitorio said:
any car with a modern ECU and a MAF sensor should correct for that though, otherwise driving up in the mountains will mean you permanently run rich and burn your cat in no time.
And im not convinced that putting (a very tiny amount of) extra air in with the same fuel will result in less performance, the chemical energy released for the burn of the fuel is still the same, but there is more gas in the chamber to expand due to the heat, so if anything id expect a (very very small, probably insignificant) increase rather then decrease, even with the same amount of fuel.
I thought the same regarding ECU/MAF sensor as after fitting I drove 1-2 miles and there was no noticeable difference, however later in the day after doing 10+ miles the difference was there, I'm assuming this is because the ECU had now adjusted as a result of the increased air flow.And im not convinced that putting (a very tiny amount of) extra air in with the same fuel will result in less performance, the chemical energy released for the burn of the fuel is still the same, but there is more gas in the chamber to expand due to the heat, so if anything id expect a (very very small, probably insignificant) increase rather then decrease, even with the same amount of fuel.
If it flows better it cleans less. Now, is this nearly noticeable difference worth having particles ingested into the engine? Also if an OE manufacturer could get any gains by changing the filter material, do you not think they would do it? Or maybe they already know.
£50 for a filter is idiocy and the essence of snake oil. There’s plenty of good test data online that show they offer no gain and have terrible filter quality.
£50 for a filter is idiocy and the essence of snake oil. There’s plenty of good test data online that show they offer no gain and have terrible filter quality.
Dunno about on the Ibiza, but a K&N panel filter on my car can give around 5 bhp on the dyno compared to the standard OEM paper filter, so it's entirely possible. Paper filters are very effective but they're not great for airflow.
In the specific case of K&N they are "wet" filters in that they use oiled cloth rather than dry paper. Better efficiency for a given flow, but require more maintenance than a disposable dry filter, hence not being used by OEMs.
Funkstar De Luxe said:
If it flows better it cleans less. Now, is this nearly noticeable difference worth having particles ingested into the engine? Also if an OE manufacturer could get any gains by changing the filter material, do you not think they would do it? Or maybe they already know.
£50 for a filter is idiocy and the essence of snake oil. There’s plenty of good test data online that show they offer no gain and have terrible filter quality.
Not necessarily, the OEM is also after a cheap easily produced filter and will sacrifice flow (but usually not filtration) to achieve that. It's certainly possible to do better than the OEM in terms of flow while maintaining the same filtration, but cost will be higher.£50 for a filter is idiocy and the essence of snake oil. There’s plenty of good test data online that show they offer no gain and have terrible filter quality.
In the specific case of K&N they are "wet" filters in that they use oiled cloth rather than dry paper. Better efficiency for a given flow, but require more maintenance than a disposable dry filter, hence not being used by OEMs.
Edited by Flibble on Friday 23 March 09:03
LasseV said:
K&N is high quality premium products with a very good air flow and filtration. However, you can be right and your cone filter application can suck ass... Cone filters need to have an air box so they could work well. Some of the K&N cond air intake kits are awesome, for example V6/V8 mustangs, GT-R and IS-F. They produce a lot of extra power in dyno. So they will work in every way.
I had read that the cone filters do work really well within an airbox and I have seen a few set up like that at car shows. They can look really good too. Good to hear that you get performance gains as well. Evanivitch said:
Come filters installed into a warm engine bay (like an NA MX5) can be detrimental.
A very valid point which many seem to be in denial off...the temperature of the airflow is just as important as the amount of air that flows into the engine, place the filter accordingly.Pete
Funkstar De Luxe said:
If it flows better it cleans less. Now, is this nearly noticeable difference worth having particles ingested into the engine? Also if an OE manufacturer could get any gains by changing the filter material, do you not think they would do it? Or maybe they already know.
£50 for a filter is idiocy and the essence of snake oil. There’s plenty of good test data online that show they offer no gain and have terrible filter quality.
Why post utter rubbish?£50 for a filter is idiocy and the essence of snake oil. There’s plenty of good test data online that show they offer no gain and have terrible filter quality.
Would you say longer lasting tyres have to offer less grip?
It's all about cost. Mass produced cars probably have a filter that cost a couple of quid to manufacture and is designed for longevity with minimum performance considerations (I've yet to hear of an eco- posting air filter myself).
Some interesting points of view being discussed.
1. Manufacturers are more interested in the best filtration possible, to support a product they have to warranty and that has to be ready for nearly ANY environment and associated conditions. They also need to consider noise as part of the environmental tests.
2. Air intake restrictions on standard engines can be driven by the filter itself, the box or the pipework. So making changes to these, if the particular car you have has a restriction, can see some benefit.
3. Cold air is the most important aspect for the power. This assumes the filter isn't utterly a limiting factor. So make sure it only gets cold air.
4. Cone filter in a hot engine bay can lose some bhp but once the speeds get up and the airflow is rushing through the under bonnet, in most cases the temperature isn't much higher. Lower speeds, or on a rolling road etc. the difference is going to be more obvious
5. On turbo cars you can end up with more boost if the air filter is less restrictive. The more boost can give you more bhp. Even with reasonable electronic boost control, you still sometimes see an extra psi. A boost gauge is helpful.
6. On turbo cars with a replacement filter setup, it is VERY rare to see exactly the same boost and more bhp. That would only be as a result of the wastegate opening earlier as the turbo is working less hard to produce the same boost. More wastegate open means the equivalent of a less restrictive exhaust which brings with it associated benefits.
7. A replacement panel filter in a standard airbox can make more noise. The thick standard paper filter itself shields quite a bit of the noise. Replacing that with a much thinner K&N panel filter does let through some of the whistles or induction roar. Not as much as going straight to a cone filter but some.
8. On the rolling road the key is always to get the coldest air in to the intake to help make the most bhp.
9. Most modern cars will implement any adaption needed for the slight increase in airflow of an improved filter/pipework setup. The car is designed to work with a brand new fresh paper filter or one that is quite clogged, so it has a range to work with. Same with the altitude and air density comment made above re: driving in the mountains.
10. Most catastrophic failures caused by airfilters are where something gets through the less restrictive filter and is ingested by the turbo at 130,000 rpm and bends the blades. Or the oil from the filter lands on the air flow meter sensors and gives a false reading to the ecu which results in running lean and then melting.
I've tested and monitored all this stuff over the last 20 years when messing around with cars and dyno tests.
Not looking to try and be the answer to all the questions but thought that might help.
Cheers,
RW
1. Manufacturers are more interested in the best filtration possible, to support a product they have to warranty and that has to be ready for nearly ANY environment and associated conditions. They also need to consider noise as part of the environmental tests.
2. Air intake restrictions on standard engines can be driven by the filter itself, the box or the pipework. So making changes to these, if the particular car you have has a restriction, can see some benefit.
3. Cold air is the most important aspect for the power. This assumes the filter isn't utterly a limiting factor. So make sure it only gets cold air.
4. Cone filter in a hot engine bay can lose some bhp but once the speeds get up and the airflow is rushing through the under bonnet, in most cases the temperature isn't much higher. Lower speeds, or on a rolling road etc. the difference is going to be more obvious
5. On turbo cars you can end up with more boost if the air filter is less restrictive. The more boost can give you more bhp. Even with reasonable electronic boost control, you still sometimes see an extra psi. A boost gauge is helpful.
6. On turbo cars with a replacement filter setup, it is VERY rare to see exactly the same boost and more bhp. That would only be as a result of the wastegate opening earlier as the turbo is working less hard to produce the same boost. More wastegate open means the equivalent of a less restrictive exhaust which brings with it associated benefits.
7. A replacement panel filter in a standard airbox can make more noise. The thick standard paper filter itself shields quite a bit of the noise. Replacing that with a much thinner K&N panel filter does let through some of the whistles or induction roar. Not as much as going straight to a cone filter but some.
8. On the rolling road the key is always to get the coldest air in to the intake to help make the most bhp.
9. Most modern cars will implement any adaption needed for the slight increase in airflow of an improved filter/pipework setup. The car is designed to work with a brand new fresh paper filter or one that is quite clogged, so it has a range to work with. Same with the altitude and air density comment made above re: driving in the mountains.
10. Most catastrophic failures caused by airfilters are where something gets through the less restrictive filter and is ingested by the turbo at 130,000 rpm and bends the blades. Or the oil from the filter lands on the air flow meter sensors and gives a false reading to the ecu which results in running lean and then melting.
I've tested and monitored all this stuff over the last 20 years when messing around with cars and dyno tests.
Not looking to try and be the answer to all the questions but thought that might help.
Cheers,
RW
Edited by Steven_RW on Friday 23 March 09:37
An old but thorough test of filter flow and filtration: http://www.bobistheoilguy.com/airfilter/airtest1.h...
I use a standard paper filter in our cars. I can live without the 0.14% of atmospheric pressure gain from a K&N
I use a standard paper filter in our cars. I can live without the 0.14% of atmospheric pressure gain from a K&N
Shakermaker said:
I always wondered about the effectiveness of these filters after I saw the bonnet up on a Ferrari F40, which did not have a K&N style filter, but what appeared to be a regular paper air filter.
If a car such as that doesn't use one, then what benefit do they offer a regular car?
Last I checked the F40 wasn't delivered on cut slicks either.If a car such as that doesn't use one, then what benefit do they offer a regular car?
Steven_RW said:
Some interesting points of view being discussed.
1. Manufacturers are more interested in the best filtration possible, to support a product they have to warranty and that has to be ready for nearly ANY environment and associated conditions. They also need to consider noise as part of the environmental tests.
2. Air intake restrictions on standard engines can be driven by the filter itself, the box or the pipework. So making changes to these, if the particular car you have has a restriction, can see some benefit.
3. Cold air is the most important aspect for the power. This assumes the filter isn't utterly a limiting factor. So make sure it only gets cold air.
4. Cone filter in a hot engine bay can lose some bhp but once the speeds get up and the airflow is rushing through the under bonnet, in most cases the temperature isn't much higher. Lower speeds, or on a rolling road etc. the difference is going to be more obvious
5. On turbo cars you can end up with more boost if the air filter is less restrictive. The more boost can give you more bhp. Even with reasonable electronic boost control, you still sometimes see an extra psi. A boost gauge is helpful.
6. On turbo cars with a replacement filter setup, it is VERY rare to see exactly the same boost and more bhp. That would only be as a result of the wastegate opening earlier as the turbo is working less hard to produce the same boost. More wastegate open means the equivalent of a less restrictive exhaust which brings with it associated benefits.
7. A replacement panel filter in a standard airbox can make more noise. The thick standard paper filter itself shields quite a bit of the noise. Replacing that with a much thinner K&N panel filter does let through some of the whistles or induction roar. Not as much as going straight to a cone filter but some.
8. On the rolling road the key is always to get the coldest air in to the intake to help make the most bhp.
9. Most modern cars will implement any adaption needed for the slight increase in airflow of an improved filter/pipework setup. The car is designed to work with a brand new fresh paper filter or one that is quite clogged, so it has a range to work with. Same with the altitude and air density comment made above re: driving in the mountains.
10. Most catastrophic failures caused by airfilters are where something gets through the less restrictive filter and is ingested by the turbo at 130,000 rpm and bends the blades. Or the oil from the filter lands on the air flow meter sensors and gives a false reading to the ecu which results in running lean and then melting.
I've tested and monitored all this stuff over the last 20 years when messing around with cars and dyno tests.
Not looking to try and be the answer to all the questions but thought that might help.
Cheers,
RW
Thanks for the informative/anecdotal response. Mirrors everything I have read prior to installing the panel filter.1. Manufacturers are more interested in the best filtration possible, to support a product they have to warranty and that has to be ready for nearly ANY environment and associated conditions. They also need to consider noise as part of the environmental tests.
2. Air intake restrictions on standard engines can be driven by the filter itself, the box or the pipework. So making changes to these, if the particular car you have has a restriction, can see some benefit.
3. Cold air is the most important aspect for the power. This assumes the filter isn't utterly a limiting factor. So make sure it only gets cold air.
4. Cone filter in a hot engine bay can lose some bhp but once the speeds get up and the airflow is rushing through the under bonnet, in most cases the temperature isn't much higher. Lower speeds, or on a rolling road etc. the difference is going to be more obvious
5. On turbo cars you can end up with more boost if the air filter is less restrictive. The more boost can give you more bhp. Even with reasonable electronic boost control, you still sometimes see an extra psi. A boost gauge is helpful.
6. On turbo cars with a replacement filter setup, it is VERY rare to see exactly the same boost and more bhp. That would only be as a result of the wastegate opening earlier as the turbo is working less hard to produce the same boost. More wastegate open means the equivalent of a less restrictive exhaust which brings with it associated benefits.
7. A replacement panel filter in a standard airbox can make more noise. The thick standard paper filter itself shields quite a bit of the noise. Replacing that with a much thinner K&N panel filter does let through some of the whistles or induction roar. Not as much as going straight to a cone filter but some.
8. On the rolling road the key is always to get the coldest air in to the intake to help make the most bhp.
9. Most modern cars will implement any adaption needed for the slight increase in airflow of an improved filter/pipework setup. The car is designed to work with a brand new fresh paper filter or one that is quite clogged, so it has a range to work with. Same with the altitude and air density comment made above re: driving in the mountains.
10. Most catastrophic failures caused by airfilters are where something gets through the less restrictive filter and is ingested by the turbo at 130,000 rpm and bends the blades. Or the oil from the filter lands on the air flow meter sensors and gives a false reading to the ecu which results in running lean and then melting.
I've tested and monitored all this stuff over the last 20 years when messing around with cars and dyno tests.
Not looking to try and be the answer to all the questions but thought that might help.
Cheers,
RW
Edited by Steven_RW on Friday 23 March 09:37
Based on your experience, what type of induction modification would you have implemented on my car or a similar modern turbo-charged petrol?
Evanivitch said:
Shakermaker said:
I always wondered about the effectiveness of these filters after I saw the bonnet up on a Ferrari F40, which did not have a K&N style filter, but what appeared to be a regular paper air filter.
If a car such as that doesn't use one, then what benefit do they offer a regular car?
Last I checked the F40 wasn't delivered on cut slicks either.If a car such as that doesn't use one, then what benefit do they offer a regular car?
if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
Shakermaker said:
No, I get that, I don't think that's a reasonable comparison to make though.
if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
OEM solutions are never the optimal for performance. Lexus IS-F gets 23whp from K&N cold air intake kit. And it is already quite high hp engine, but it has stil room for improvements.if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
http://www.motoiq.com/MagazineArticles/ID/1827/Pag...
S9JTO said:
Thanks for the informative/anecdotal response. Mirrors everything I have read prior to installing the panel filter.
Based on your experience, what type of induction modification would you have implemented on my car or a similar modern turbo-charged petrol?
Hi,Based on your experience, what type of induction modification would you have implemented on my car or a similar modern turbo-charged petrol?
It really depends what you are aiming for. If it is cheap running, long mileage and long life expectancy for your engine, I would stick to the standard air filter and I would replace it regularly. You remain confident it is getting the best filtration to protect your engine and it is cheap to replace regularly.
I would check that the standard airbox has a dedicated cold air intake pipe from behind the bumper.
So I would know I was getting the coldest available air in the best filtration.
If I had other mods carried out on the car, such as a boost upgrade (re-map, chipped whatever you want to call it), I'd carry out a test to see if the standard kit was restrictive. If it was proven not to be restrictive I wouldn't change it.
There are simple ways to test the restriction but they require a rolling road, other wise it is all speculation.
Very few airfilter mods will get you a BHP increase that is a genuine improvement that you can tell. Often it is noise or a slight sharpening of the throttle response. But very slight.
On my mini (1.6 turbo 2007 version) the std bhp is 170. Once we were at 250bhp with the completely standard intake pipes and airfilter we started looking to find restrictions. Initially we removed all the pipework before the turbo and tested it. Zero pipework, zero airfilter etc. As unrestrictive as you can get. We also channelled cold air to the turbo using a massive fan with a long trunk pipework. This is the max you can expect from airfilter mods. We gained 7bhp. We then worked back from there adding in filtration and pipework and tried to maintain our 7bhp.
The 7bhp was aligned to an increase of 1psi boost. So if my car was utterly at its boost limit we would have had to turn it back down by that 1psi and chances are we would have lost nearly all the 7bhp.
What was interesting was putting a trumpet shape on the turbo housing inlet. This must be a more natural way to gather air and less sharp edges and this gave us another few bhp. So we now knew the max bhp available and worked backwards.
The reality is if you want a real world more usable BHP that isn't a handful of BHP, you need to seek out bigger and better mods. Airfilters won't win you a race. You just need to treat them like an area that by modding you are at risk of worse filtration into your turbo/engine, at risk of drawing in hot air rather than closed pipe cold air only stock airbox and losing bhp. You also need to accept that most people that replace the stock airfilter do so with a foam or k&n oiled filter that if you do not continue to service you end up with worse filtration as you see it as fit and forget.
There is a whole bunch of info. If you want to discuss your specific car, feel free to explain the engine a little bit more and any other mods that have been completed. Also what your longterm ambition is.
Cheers,
Steven RW
Shakermaker said:
Evanivitch said:
Shakermaker said:
I always wondered about the effectiveness of these filters after I saw the bonnet up on a Ferrari F40, which did not have a K&N style filter, but what appeared to be a regular paper air filter.
If a car such as that doesn't use one, then what benefit do they offer a regular car?
Last I checked the F40 wasn't delivered on cut slicks either.If a car such as that doesn't use one, then what benefit do they offer a regular car?
if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
Then, looking at cut slick tyres, ignoring the fact there weren't many/any to pick from in the 80's, they'd put much higher loadings through the suspension and drivetrain and with some engines the increased lateral loads can cause oil starvation, which Ferrari would have to pay for under warranty.
This is all stuff that aftermarket suppliers do not have to give the same level of consideration to because they do not have the same level of exposure.
Shakermaker said:
Evanivitch said:
Shakermaker said:
I always wondered about the effectiveness of these filters after I saw the bonnet up on a Ferrari F40, which did not have a K&N style filter, but what appeared to be a regular paper air filter.
If a car such as that doesn't use one, then what benefit do they offer a regular car?
Last I checked the F40 wasn't delivered on cut slicks either.If a car such as that doesn't use one, then what benefit do they offer a regular car?
if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
You can up the boost on an F40 and get more BHP. You can also move to a full tubi unrestricted beast of an exhaust too.
You can add K&N filters I guess but I would be more worried about filtration for my mega expensive engine than the extra 5 bhp.
RW
Funkstar De Luxe said:
If it flows better it cleans less. Now, is this nearly noticeable difference worth having particles ingested into the engine? Also if an OE manufacturer could get any gains by changing the filter material, do you not think they would do it? Or maybe they already know.
Everything on a car is a compromise between price and performance. Manufacturers will prioritise cost per-unit and the ease of disposal and replacement over performance when specifying an air filter.The BMW Performance air-filter upgrade for the 330i E90 (for example) was a K&N filter - carried the branding and everything - marked up drastically because it came in BMW Performance packaging.
I've personally fitted dozens of them, but don't bother anymore as the hassle of washing them, waiting for them to dry, and then re-oiling them isn't worth it IMO. Life is too short.
Okay you've got me slightly worried about the filtration on my K&N Panel Filter - Seriously, what're the chances of my engine inhaling something harmful via the filter in comparison to the standard filter? Surely it can't be likely...
According to K&N the filter is good for 50,000 miles before it needs cleaning, I won't even have the car then... Either way I plan to give it a check after 10k.
According to K&N the filter is good for 50,000 miles before it needs cleaning, I won't even have the car then... Either way I plan to give it a check after 10k.
LasseV said:
Shakermaker said:
No, I get that, I don't think that's a reasonable comparison to make though.
if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
OEM solutions are never the optimal for performance. Lexus IS-F gets 23whp from K&N cold air intake kit. And it is already quite high hp engine, but it has stil room for improvements.if a K&N air filter is supposed to make air flow better and therefore improve engine performance over a paper filter, why didn't a company such as Ferrari, making expensive high-end supercars, not choose to put one on the F40?
Or, have they started to do so on cars made at some point in the last 30 years?
After all, with the prices of some of these cars, a £20-30 air filter is incredibly small change for what would apparently be a huge performance gain.
Having said that, I have fitted K&N filters or had them on cars I have bought in the past, and enjoyed the noise they have made, though I don't think they did anything other than improve the noise.
http://www.motoiq.com/MagazineArticles/ID/1827/Pag...
I don't believe the manufacturer was ever wanting that extra BHP, otherwise they would have had it.
RW
Gassing Station | General Gassing | Top of Page | What's New | My Stuff