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I found a mention of improved performance and reduced fuel consumption when using non paper air filters in these forums. Naturally, that interested me - who does not want more power and paying less for petrol ? :thumbs:

However googling around while trying to decide which filter to try, I found this:
Tuning the LET - Intake

which links to this:
Air Filtration Test

Now I am not so sure that I want to try a new filter anymore :eek: :confused:

Comments anyone ?
 

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K&N filters only get gains from not filtering enough.

A mate ran them in his off-road racer, which re-ground its bores and had massive compression loss after the second event as all the dirt went through the filter into the engine. He changed to OEM style filters and has never had an issue since.

K&N filters also need oil on them when they're cleaned, this oil can be sucked from the filter on to the MAF and trash the MAF, too.

I wouldn't touch them with a bargepole.
 

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K&N filters only get gains from not filtering enough.

A mate ran them in his off-road racer, which re-ground its bores and had massive compression loss after the second event as all the dirt went through the filter into the engine. He changed to OEM style filters and has never had an issue since.

K&N filters also need oil on them when they're cleaned, this oil can be sucked from the filter on to the MAF and trash the MAF, too.

I wouldn't touch them with a bargepole.
+1

Non paper filters are killing the MAF sensor.
 

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Check to see if your filter is the same part as the one in the fastest Cloverleaf version. IF so, you know it can flow enough air to feed one of those at full chat (and THEN for 12,000 miles in dusty Italy or whatever the service interval is)! Let's be honest here. The car manufacturer isn't going to make something as simple as his air filter the bottleneck, for the sake of another few square inches of paper! They usually have enormous reserve capacity before they start imposing a restriction on the engine.
 

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+1

Non paper filters are killing the MAF sensor.
Easily fixed. Run for a day with maf removed so air and oil vapur get sucked through until it dries. That's only if you pummel it with oil.

I've been running a CDA for over 25k miles with no issues.
 

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Easily fixed. Run for a day with maf removed so air and oil vapur get sucked through until it dries. That's only if you pummel it with oil.

I've been running a CDA for over 25k miles with no issues.
And what about any damage to the engine caused by the poor running if you coat the MAF with air? Or damage caused by running without the MAF?

What about the damage the poor filtration of a re-usable filter can do to the engine?

What actual performance gains are there for this risk?
 

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Coat the Maf with air? What are you talking about. The MAF is deisnged to be in air flow.

The Car will default to a set of tables that allow the car to run. Albeit a bit rich rather than lean. If you drove the car like this for many thousands of miles then you'd eat into the mpg and you would eventually destroy the Cat.
You may even get a bit of bore wash from the extra petrol.

However I am talking about removing it while you run the filter for a short period and then popping it back once the oil from the filter has been removed or sucked through.
Or how about...Don't soak the thing in oil... Job done... A light spray is all that's needed.

The filtration on aftermarket filters tends to be far superior to the standard box and paper filter. Thus less restriction and better filtration.
Which leads to more torque and power. Not much admittedly. But its still something.
 

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Coat the Maf with air? What are you talking about. The MAF is deisnged to be in air flow.
Sorry - coat it with oil.

It would be rather something of a ballache to run without the MAF in the airflow, wouldn't you say? What are you going to do? Replace it with a bit of plastic tube for a while?

I would argue against the 'better filtration thing' especially on the disasterous results I've seen with people using aftermarket cotton filters - they acheive the better flow by less filtration, which won't do the motor any favours in the long term.
 

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Unfortuantly I can not prove it. I just have one and noticed the difference through the pedal.

Removing the maf would not idle quite right but for a small nip round the block and then put it back in it shouldn't be too much of an issue. Least the oil is sapped through and dries so no damage is done.

But I've oiled lightly and then run with the maf in without issue. I think its just said because people must put far too much on it.

Same as a water can injest rain (look at F1 cares) the water or mist by the time it gets sucked through the engine actually helps the combustion chamber cool down. Same as petrol is a liquid that gets compressed. Oil is the same. So long as its not too much it'll be okay.

Anyway. You choose what you want. I got a good deal on the CDA and can live with cleaning it every 7k.

Paper filters are cheap and easy to replace.
So you can pick whatever suits you.
 

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they acheive the better flow by less filtration, which won't do the motor any favours in the long term.
Yes, of course they do. But that doesn't always equate to guaranteed damage. There are certain problems linked to certain types of filters being used on certain types of cars - such as the risk to the MAF when using an oiled filter - but that's where one has to do their research and make an informed decision. Simply accusing all performance filters of being a risk is much like the blanket statement that Alfas are unreliable cars. And how long term are we talking? A few thousand miles, or a few hundred thousand miles?

There's plenty of people who have used such filters for years and years without problem. They probably outweigh those who HAVE had problems.

In terms of filtration, whether they are a risk depends on the manufacturer getting the right compromise between increasing the airflow compared to a paper filter whilst not reducing the filtration qualities to the point that it poses a risk. Why aren't such filters used as OE if they are better then? Manufacturing costs of course. If K&N filters where killing engines left right and centre would they be the established company they are to date? If an vehicle being driven off-road in an inherently extreme dusty/dirty environment suffered damage as a result, I would presume that the filter being used wasn't the right filter for the job - I wonder if K&N et al have a warning/clause in their product information to cover this, and I wonder how that one would go down in a court case.

Personally I have no qualms over using a "performance" filter on any car so long as it's a recognised brand such as K&N, Green etc, rather than an unbranded cheap eBay jobbie, but if it's an oiled filter and near to a MAF then that has to be considered.
 

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I remember my old 2 stroke days. I used a pair of tights over the carb as an air filter when mine was shafted. I also had to start it using WD40 straight into the carb to fire it up.

Well least till I got a new working choke and carb. Still all good fun. It didn't die by the way. I still have it. Twenty years one. I've done a grand total of 35 miles on it since I rebuilt it. (NSR250).
 
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