What, if anything, does fitting a K&N air filter do?

[guest24]

Who's fitted one, and does it really make any difference? And by difference, that can be positive as well as negative!!

Or, is the K&N filter the start of the slippery slope of 'tune this beast badly by spending lots of money'...? 

[squirrelciv]

My Dommie came with a K&N already fitted so I couldn't comment on whether it 'improved' things or not. Must say I liked the fact that you could clean it and re-oil it rather than replace it though

I'm tight me.

[Gaylord]

Hello Cossack person.
I think the simple answer is it costs, money,fuel,hassle and maybe engine life. I have found recently that some runs on a Dyno machine will tell the truth about engine performance. Iam now using less fuel, have 5hp more and it runs better, money well spent.

[guest146]

You have to remember if it lets more air through it can only do so by not filtering it so well unless its of a larger size. A  better option is to follow the dynojet recommendation and cut the funnel on the air intake so letting more air through.

Ken

[guest27]

What and reduce the silencing..

 
R

[johnr]

changing the air filter in isolation will do little. if you fit a free flowing filter, it doesnt necessarily filter the air less, but just more efficiently, however, more air alone is no good, if you put more air in the only way to get more power is to also put more fuel in too. this then means that you have more mixture going into the engine and can give power gains, but only if the exhaust system is so tuned to allow the gasses to escape fast enough. you can then get caught up in the whole cams valves, timing, ignition big bore compression slippery slope of tuning the lump.

[Andy M]

Changing the filter alone does naff all, good or bad to performance IMHO. What an oiled filter gives is something you can service without a trip to a bike shop. Get your paper filter soaked or clogged with sand and the only solution is to bin it. Get a fabric/foam one out and if push comes to shove you can wash it in petrol and re-oil it with engine oil.

Andy

[Steve H]

If the filter is essentally the same design as the original with the same number of pleats, then chances are you wont see much difference. On the SRX any gains tend to come from removing the air box cover or the snorkel, which indicate the original filter flows enough.
Apparently it takes a few miles before paper filters are fully effective. The only issue I have with oil based filters is that I find it very easy to over oil them.