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-   -   K&N Air Filter, the side effects. (https://www.team-bhp.com/forum/technical-stuff/24712-k-n-air-filter-side-effects-9.html)

In humid conditions these filters get choked faster than usual unlike in dry climate regions. Considering the fact that you have already clocked 15,000 Kms, I guess it's just about time to check it once, now.

I was cleaning at 20k interval when I was in Chennai. Now after coming to Bangalore my daily drive route is too dusty and it was clogging up too much so switched back to stock filter. Planning to use the K&N in my dad's Linea.

So take a call based on your driving conditions.

My car's OEM paper air filter costs about Rs 700 and provides excellent filtering when its new/clean. For the price of ONE K&N filter (it is about 6K) I can replace the stock part about 9 times. In other words, for the price of 1 K&N filter, I can drive the car for 90K kms, and change the OEM filter every 10K kms which is well within the recommended change interval of 40K kms.

The K&N does not makes sense.

Understand where your coming from, but the performance difference is kn is unmatched on paper filters and even more if it's a remapped car like mine.

Also which car's air filter are your talking of? Rs.700 seems pretty expensive for paper filter!

Is this still a debatable topic?

As I had mentioned earlier, a cleaned and re-oiled cotton filter and a new oem filter are same, the former will show a slight easiness in the initial gears. But that ends there, rest are all placebo effects in a stock map as it wont consider the extra air.

The difference is visible after using it over a period of time, once the oem gets clogged it decreases the flow but due to the design of the cotton filter it allows more air comparatively. Changing the oem filter is the option to retain its performance, cleaning wont give the desired results always in a paper filter for these kind of critical components.

The benefit in stock form is that the overall cost for replacing the filter whenever it clogs, cleaning the cotton filter will make it fresh as new. So the maintenance and the initial cost of the cotton will be recovered fast in this way.

However the performance difference will be possible if we have a remapped car as we can tweak the map to accommodate the extra amount of air or pressure at the manifold.

My Figo petrol has been running on a Cosworth panel filter for more than 15k kms.
Earlier to that was a BMC conical oil type filter which used to get dirty very fast and in turn affected the power delivery.
Once I started using the panel filter, not only the smoothness increased, but the noise reduced compared to both stock and conical filters and I could still rev smoothly unlike with the paper element filter that was factory fitted.
I do clean it once in 6-8 months regardless of what conditions I drive in.

My car is not re-mapped , but has a FFE with which this filter definitely helps.

I believe it is a placebo effect too.

This is a stock Toyota Corolla Altis. The only "change" is I swapped Toyota's factory fitted standard Denso plugs with Toyota/Denso Iridium plugs purchased from the dealer. The other change is the ICE system.

The air filter is also made by Denso and it is an OEM part. There are differences in quality of paper filters too for e.g. the porosity, design/surface area, material used, size etc which may differ from car to car or manufacturer to manufacturer.

I prefer clean filtered air going to the engine so I chuck the old filter every 10K kms and put in a new one. Heck, for the kind of money one pays for a K&N I could swap the Denso filter @ Rs 700 every 5000 kms and still come out smiling!! A Rs 6K reusable air filter that requires cleaning with a manufacturer specified cleaning solution doesn't make sense to me at all.

Since you say it makes a difference on a remapped car, what kind of BHP does your car deliver with the remap but with an OEM filter v/s the K&N?

These have been debated already and so I'd prefer not to comment. But then again, for a stock car yes, the stock filter will do the job at best.

I have not measured to give you the numbers, but the difference in power delivery on the highway is substantial enough to make one miss the KN :)

See that's where my question arises. Even if you remap the car, the volume of air consumed by the engine is about the same as before the remap. IMHO the only time it may make a noticeable or substantial difference is if a NA engine is turbocharged or supercharged. A turbo or supercharger will increase the volume of air being forced into the cylinders thereby possibly necessitating a redesign or replacement of the air intake system including the airbox and air filter. I am more than willing to be corrected.

The remap probably works on the ignition, valve and fuel injection timing & a minor increase in the quantity of fuel injected at a certain RPM or RPM band to make the engine more responsive or deliver more power. At no point does the engine require that much extra air (compared to its requirement with the stock ECU map & a stock airbox) where the stock filter and airbox become restrictive and affect performance.

BTW I also have a Palio 1.6 GTX. :) She's in stock condition too.

Power delivery on the highway? Please don't get me wrong mate. I am not trying to belabour a point but that's precisely where the placebo effect is. I believe the performance difference is because of the remap. Not the air filter.

Put the car on a dyno with the K&N filter, remove it and insert a fresh stock air filter. Swapping air filters is a 5 minute job for someone who knows how. I'll be very, very surprised if you see a difference.

I am aware K&N makes vague claims about an increase in power but that's probably with 6-8 cylinder high output engines, not the puny sub 2 litre tuned-for-fuel-efficiency commuter car motors that are the norm in this country.

This so called benefit also comes at the cost of filtration performance. And in a hot dusty country like India that's not a good thing. There's plenty of feedback here:

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

and here

https://www.bobistheoilguy.com/airfilter/airtest3.htm

PS - The OEM spends millions of dollars in R&D. And if K&N type drop-in filters were the panacea to performance problems they'd have done it too.

Hi Aj, sorry to bump an old thread, but I too received my BMC stock replacement filter for my figo today, it also has the same part number as the one you got as well . Though unfortunately my filter refused to fit in my car's airbox. It seem's to be way too long and the difference in size is obvious when I compare it to the oem filter! :deadhorse
Did you have any such issues? would you have any idea as to whats wrong here? Any help would be much appreciated!

Attaching some pictures for reference.

Edit: I had purchased it on Boodmo and have already reported a return.
https://boodmo.com/catalog/part-air_filter-32863469/"]https://boodmo.com/catalog/part-air_filter-32863469/[/url]

Turrrb0

Got down to cleaning my K&N Air filter after 19000km.

Kit used 99-5050 K&N Recharger

Time required - Approx 8 hours

1.Used the cleaner to spray on both sides of the filter; then allow to soak for 10 mins

2.Hose down the filter from the clean side back to the dirty side

3.Repeat Steps 1 and 2 till the wash water is free from dirt.

4.Allow the filter to dry naturally. In this case I dried it in the sun for approx 4 hours.

5.Oil the pleats on the filter with the recharger oil.

6.Allow the oil to soak in for 20 minutes.

7.Touch up with oil to bring a uniform pink shade back.

Lessons learnt : After 3 rounds, it would be better to soak the filter in mild detergent solution for longer to bring the filter back to its base bright white shade. Only then will the filter look bright red after it is oiled.

Now, for the pics. Look at the amount of muck this had trapped.

Am attaching a shot of the MAF sensor - no carryover dust there at all.


Dirty filter


Wash water after rounds 1 to 5










Clean & Oiled filter

A terrific video comparing different filters, especially it shows how much dirt can pass through k&N filters

https://youtu.be/sJ3L-E-ufYo

I have installed a K&N filter on my Kawasaki Ninja 1000. After 3000 km I went for a service, during throttle body cleaning I noticed gunk around butterfly valves.
I have always observed my bike carefully during service and this is the first time I have seen gunk like this.
I live in Gurgaon and there is a lot of construction work going around my house.
Now I am switching back to OEM filter on next service.

Picks attached.

PS: The loose dust that appears on the valve settled during opening the throttle body.

Why are you surprised? It’s common knowledge that the K&N is not suited for dusty/contaminated environments due to its better breathing capabilities.

I have been using the K&N replacement filter in my Micra for almost 150,000kms now without any issues, but I always change the oil & oil filter every 5,000kms. I’ve seen the throttle body get dirty the same as when using the paper filter before I switched to the K&N.

Bottom line, DON’T use K&N filters if you live/drive in dusty environments or if you don’t like to clean & re-oil them using the recharge kit. I clean it once a year and the kit restores it to its red glory. Also, for the times I do drive far away & come across lots of dust/debris, I have an OEM paper filter under the seat, just in case.

I use a green cotton air filter in my Pete's tuned Verna Crdi that has done 110k on the odo. It makes a significant difference in performance compared to OEM filter. I clean it every 5000-6000km with mild soap detergent and coat it with oil.
Prior to this I have used k and n filter on a hyundai santa fe V6 and a Toyota Prius and noticed a ~5 percentage improvement in pickup.
I don't need further convincing as long as I am able to perceive an improved performance which is what I care about.