KN Filters

[GillC1]

Hi

Just wondering does anyone else use KN Filters? If so do they make a difference. does anyone have an opinion as to whether they are worth the money

thanks

 

[Alan Partridge]

No I don't. Do you mean air filters? The selling point for these is better airflow = more power. This implies that the car is being strangled by the normal air filter, which should not be the case if it's clean. The main purpose of the filter is to remove grit to prevent engine wear, You might reasonably expect better airflow to mean less filtration and more grit, as is suggested by the claims here -

http://www.honestjohn.co.uk/forum/post/index.htm?t=64541&v=f
I intend to continue using genuine manufacturer branded filters changed according to schedule. K&N aside, I wouldn't use a pattern air or oil filter on a car I cared much about either.

 

[Rich]

Air filters can be restrictive even when new. It is down to the make up of the materials used where OEM suppliers use paper but good quality manufactirers use woven materials like cotton or different grades of open cell foam which once layered will catch particilates yet still have the option to be cleaned where paper one have to be thrown away. The K&N filter is a bit less restrictive but is still as good at filtering out particles. I use K&N in my bikes not to increase performance but the main benefit is they can be cleaned and unlike a car a bike usually has a ram air type of intake where the air has direct access to the filter and can almost be seen if you look into the air intakes, a car has a more conveluted intake and heavier particles should be less likely to reach the air filter. K&N are one of the worlds biggest aftermarket air filter brands and will perform as well or better than OEM paper filters.

 

[Dustydog]

I've used a K&N filter for the last 30k miles. As I understand it , the air flow is less interrupted and even as it gets dirty the airflow does not reduce as in an OEM. I clean mine with the K&N fluids and reoil with the K&N product.

Various tests I have read show a marginal improvement but I will say there is no real noticable difference.The OEM on my car was a change at every 10k miles and that cost

 

[RogerL]

The improved airflow of K&N filters will give marginally more top end power at wide-open throttle, with quicker throttle response on non-turbo engines at the bottom end but these are of limited benefit off the race track. Even on rolling road tests, before and after figures show only small increases.

The downside of K&N, and similar filters, is the increased engine wear because more particle dirt gets into the engine.

I wouldn't dream of fitting one.

 

[Rich]

RogerL,

The K&N filter is not designed as a race filter. It has a small benefit in flow but is not as "open" as the DT1 filters I use in the race engines. I use K&N in my road bikes and with the high gas speeds of the bike engine combined with the very open nature of the intake I would be very careful which filter I use on the road. The 600 I have revs to 16,000 RPM and gas speeds can reach speeds which are approaching supersonic where a low revving car engine will be half that. K&N,Pipercross and DNA Filters all make very good road based filters and Pipercross does a specific race filter which will need more attention and cleaning after every race meeting.

 

[Angus1]

Fitted a K&N to an MG Maestro at 40k, seemed to improve throttle response and quantifiably improved emissions (I have a digital tester).

The car was still running sweet as a nut and went like a rat up a drainpipe at 135k when the body dissolved.....

Sold the engine on as it used no oil, had excellent compression and it was still going strong 3 years later.

Everyone has their own viewpoint. Mine is based on personal experience rather than theory.

Would fit another, no problem.

 

[Glenn_5132962]

I use a K&N on my old MGB roadster & it does make a small improvement to performance.

For modern cars their are 2 types. Those that fit in the original air box and the cone type one's that replace the air box.

Personally I would avoid the later as as manufacturers take a great deal of care to get cold dense air into the engine. Throwing away all this trunking etc & fitting a cone right next to the engine means the car will be breathing warm air & you probably end up worse off.

 

[michaelg]

a k n filter will give better performance not a massive amount but will differ on different cars i use one on my picasso 1.6 also put split fire sparkplugs in the two combined give me quite a bit more performance when towing the van kn filters give increased airflow but still filter harmful dirt which could damage your engine the only reason manufacturers fit paper element filters is cost a kn filter will outlast 1o paper element filters they do have to be cleaned and reoiled as kn instruct hope this helps