hey great comparo nikhil...

very interesting.

wow wow .. this is interesting

this is the point i was trying to get accross to people who were raving madly about k&n filters. i'm NOT trying to start a fight here ... so please don't take any offense ...

the drawbacks i see of k&n are as follows :

a) it voids manufacturers warranty. no doubth the filter itself comes with a million mile warranty. don't worry, your bike is not gonna last a million miles. but lets you your engine goes kaput due to bad petrol or abuse, you'll be left stranded.

try out the filter after you warranty period ...

b) extremely high cost. stock filters cost a couple of hundred bucks. easily last a min of 15k kms. do the math ... lets say a filter costs 200 rs. and u change one every 15k ... lets take the average life of a bike to be 100,000 kms ... 200 x 7 = 1400 rs. which is still cheaper than a single k&n filter.

c) k&n filter to 99% of oem specs ... in laymans language, a stock filter in relation to k&n has 100% effectiveness. no points for guessing which provides cleaner air.

d) unless any bike is dyno'ed, one cannot conclusively prove that the filters are better. just because the bike sounds 'louder' or 'better' doesnt mean it's running faster.

but anyways, the point being, why sacrifice engine life for performace, which is actually non existent in the first place.

for some reason i feel im opening a can of worms again.

right said nikhil..
but den y r these famous d world over? i think the answer is that these r basically famous in the rally circuit where there is ntn as "manufacturer warranty". also sponsors can afford money for the filters. also coz rallies happen in dirt areas too,this is where k&n filters may/can provide more air to the engine.. the engine may get damaged in the long run due to some particles which dont get stopped by the filter but den these rally car engines r not meant for thousand of kms..
so me thinks dat such filters r not suitable for normal usage of machines..

hmm they aren't exactly famous because of a quality product ... but just because they have a lot of money, auto shows, races etc have their banners n all put up ... most of the times, race cars run without the filters ...

also, just because, a certain manufactueres logo is painted on a race bike or a car, doesnt mean that the part is being used in that vehicle.

it's a make believe world.

right said nikhil and if u gonna ride ur bike here where dirt is every where u will screw up the engine sooner rather then later

I believe that it is True.I had changed my filter and got K & N kit for 3400 from Performance Auto.The bike became noisy and I did seem to find much increase in Performance.I had the kit for 3 days and I tested the bike for acceleration and Top speed and it does not increase the Top speed as the RPM Limitor cuts off at 8500 rpm and max speed attained over DND flyover was 120 km/hr.I have tested my bike on Delhi - Chd Hwy where I was able to attain a speed of 132 at 9200 rpm but it attains that speed after 3-5 mins of continous acceleration and once each showed the Red Line at 900 rpm I stopped accelerating.I had returned the kit to Performance Auto in Noida Sec 2 near McDonalds and had to suffer a loss of 2000 bugs but then I had fitted my old stock filter and I beileve that works good.

yeah ...filters r a waste of money .I thought a lot before finally not to go for it,...instead we can invest on free flow ,that might increase the performance .

these filters are used for racing, where they will throw away the engine after a few races regardless of the number of hours/kms it has run so it makes no differance there.. you and i run our bikes for transport well and a little(lots) of fun.. thats where filters at the price dont become worth it.

Not to douse the elation but please note
1) The test there was for filtration abilities and I didnt hear anybody claim that the filtration of the K&N was better than the stock. Mebbe i am not listening hard enough. But then the engine damages possible are a given once u expect performance. Expecting a 15 year engine life along with blistering performance is dumb.
2) Bob uses stock airbox replacement filters. That did not change the shape or area of the airbox. Does not put his findings in question but it does not analyze how a change in the filter shape helps or detracts. Pods are known to flow far better than stock airboxes at high RPM. It sure puts me off from buying a straight replacement filter.
3) Most stock manufacturers in India design an airbox based on what the flow requirements are for the bike in city in normal riding conditions or whatever is the room left by the vehicle design, whichever is lower. Smaller airboxes are good for mileage. Lesser air flowing, less fuel required.

K&N's and cotton/gauze filters are road use filters not meant for the grit thrown up by dirt roads. I am a little concerned about the dust track rides a few of us took part in.
And Foam filters are only good if they have some thickness. They are body filters and not surface filters.

As to which is better, the question you want to answer is, what is your objective?
-Ajith

good points.

but in your opinion, is the perfoamce increase justifiable for the money and effort which is spent? not to metion less that ideal filtraion. IMHO paper filters work the best.

what say?

ppl, me do not have knowledge of air filters, but just wanted to ask dat da comparison was of car air filterz.

Now, are da air-filterz of car & bikez same !! if not then how can we relate the test done for completely diff m/c with da bikes !!

just curious !

cheerz

Brilliant article Nikhil, also i wud like to know that how good is it putting such filters in our bikes coz the dust level in India is much higher than in the countries abroad..