K&N air filters

[Matt_N]

Quite an interesting article on induction kits:

http://www.mkiv.com/techarticles/filters_test/2/

Tested for filtration properties aswell as power gains.

[Ikemi]

You could always drill some big holes in the airbox - That'll make more noise

[ninjaboy]

OzCupra said:

ITG for me over K & N panel filter... Although the major brands to be honest isn't much in it in terms of performance gains.

In fact you'll be lucky to see any, maybe a little, better throttle response maybe? The noise is the main reason and for that alone i'd get one.

There not expensive by any means so it's worth a punt!

I'vr got a ITG on the TF and it seems far better than K&N filters which i an end cap fall off on which they would'nt fix under warranty until i pushed. MGF central did a test on cones and panels and they made more of a diffrence than you think expecially on torque.

Edited by ninjaboy on Thursday 6th August 14:16

[Roman]

Fitted a K&N panel filter to a ZR105 (so basically the same engine as yours). I doubt it added more than 1-2bhp to peak power output but the car was noticably smoother and slightly more responsive at low revs.

[Kenny-Mack]

isn't a standard filter about £5 from a motor factors and a K&N one about £60?

seems a long way to go to save money 12 services? ... so assuming your changing your paper filter every 10K miles your keeping the same K&N filter on for more than 120K Miles?

I find it hard to believe a K&N filter will save you money over a paper filter.

[useyourdellusion]

stealthgrow said:

Niffty951 said:

stealthgrow said:

Niffty951 said:

Dyno testing on a 1992 rover mini when I was 17 we got a 5hp gain just from changing the filter to a K&N over 2 or 3 other performance filter types.. later we discovered this is because the K&N doesn't actually stop/filter anything getting through and makes the inside of your engine look like no mans land at the battle of the somme! This then gives you a reduction in power!! Moral of the story. If your car only has 76hp 5hp isn't worth trashing your engine for! You might as well just abuse the car more to get that little extra out of it!

Total rubbish! it really gets on my tits when people give out such false blatently made up on the stop advice!

A knn will filter more particles than 99% of standard filters and at the same time allow more air to pass!

In theory this should give performance gains most of the time very minimal and not worth it but in some cases it can have the opposite effect and you can loose power due to messing with and confusing the air flow sensors.

and 5hp gaim from changing the air filter on a rover mini? i find that very hard to belive! i fitted a knn air filter full stainless exhaust and 4 branch manifold and a kent cam to a 1989 fiesta xr2 and only got 6hp extra.

Edited by stealthgrow on Thursday 6th August 13:31

Sorry but this is as tested not some internet search or trolling about something I know nothing about. We actually spent a day on a dyno with a range of filters and a mini 1.3 mayfair and compared results. Increasing the size of the holes in the filter without increasing the thickness of the filter lets more through it.. air and crap. Simple. Wan't me to find you an article to back up my experience? Google it.

This makes no sense? you tested a range of filters and increased the size of the holes in the filters? how on earth did you do this there are millions upong millons on holes in theese air filters? futher more why did you increase the size of the holes in the filters and what did you use to do that? seems a very unfair test if you are modifiying the filters your self.

you say you later discoverd the knn dosent acutlay filter anything and makes the inside of your engine look like no mans land? again how did you come to this conclusion i take it you also removed the cylinder head when you noticed the inside of the engine looked like no mans land?

i have ran cars with no fiters at all. one i rember very well my old renault 5 gt turbo! no filter what so ever that engine was rebuilt by my self manny times with and without filters and i can guarantee you that you would not be able to tell by looking at the inside of the engine that a car has been ran with no air filter.

an engine ran with no air filter will admitedly wear faster than one that has one and more importanly stop any big objects that could destroy a cylinder chamber or piston immediantly but aside from big parts ceartinly nothing that would have anychance of passing though a knn the wear on the engine would be so minimal compared to one ran with an airfilter.

Edited by stealthgrow on Thursday 6th August 13:48

'He' didn't enlarge the holes himself. He's refering to the filter having enlarged holes from the off.

Incidently, why did you run your cars without any air filtration? Especially after rebuilding your 5gt Turbo engine twice?

THIS is what makes no sense to me?!

[morgrp]

Niffty951 said:

Dyno testing on a 1992 rover mini when I was 17 we got a 5hp gain just from changing the filter to a K&N over 2 or 3 other performance filter types.. later we discovered this is because the K&N doesn't actually stop/filter anything getting through and makes the inside of your engine look like no mans land at the battle of the somme! This then gives you a reduction in power!! Moral of the story. If your car only has 76hp 5hp isn't worth trashing your engine for! You might as well just abuse the car more to get that little extra out of it!

+1 totally agree

If you like pitted valves from superheated particles of grit that haven't been filtered go for a K+N

[off_again]

To be fair, it really depends on what type of car and what type of tune it runs. For example, a modern car with a powerful ECU will automatically sense airflow and change the flow maps and injection settings, so a freer air filter is unlikely to make any difference at all. In some cases it might even make it worse!

That said, some cars run in a very de-tuned state and with very restricted airboxes. For example, some older Jeeps are setup this way and simply changing the airbox or swapping to a freer air filter can make a significant difference - maybe even up to the manufacturers claims! Certainly seen this myself in the past and it does allow the engine to breath better and hence perform more efficiently.

Are they worth the £25 or so? Debatable. A decent quality air filter is the best place to start, rather than some cheap replacement part. Surprisingly some owners never replace theirs and performance will degrade over time. The wife's Golf had this and a quick swap out of all the filters saw the thing fly and fuel consumption jump from mid-20's to early-30's with no issue! Now even pulls early 40's on a good run, and that's with a standard, but quality, replacement set of filters.....

Best way to make a car go fast? Make it stop better.....

Forget trying to improve the engine and make sure it runs well. Treat the engine to some TLC -decent oil, regular servicing, quality components and such like - and you should keep the performance at or even potentially better than it was originally. Cheapest, safest and easiest way of doing it, and it doesn't cost a penny more on insurance because its not a modification.

[pringle1988]

Kenny-Mack said:

isn't a standard filter about £5 from a motor factors and a K&N one about £60?

seems a long way to go to save money 12 services? ... so assuming your changing your paper filter every 10K miles your keeping the same K&N filter on for more than 120K Miles?

I find it hard to believe a K&N filter will save you money over a paper filter.

I got my KnN second hand for £45 after going into a motorist discount store and seeing that it is £22 for a paper filter for my car. Im now about to do its 3rd service so I am starting to save. Id keep the KnN for the lifetime of the car. They come with a 1,000,000 mile warrenty.
(Im talking about the induction kit not the replacement panel if that matters)

[Kenny-Mack]

off_again said:

To be fair, it really depends on what type of car and what type of tune it runs. For example, a modern car with a powerful ECU will automatically sense airflow and change the flow maps and injection settings, so a freer air filter is unlikely to make any difference at all. In some cases it might even make it worse!

surely if the ECU detects more air flow and adjusts the fuelling the car will run better with a better filter? rather than run crap?

[Kenny-Mack]

pringle1988 said:

Kenny-Mack said:

isn't a standard filter about £5 from a motor factors and a K&N one about £60?

seems a long way to go to save money 12 services? ... so assuming your changing your paper filter every 10K miles your keeping the same K&N filter on for more than 120K Miles?

I find it hard to believe a K&N filter will save you money over a paper filter.

I got my KnN second hand for £45 after going into a motorist discount store and seeing that it is £22 for a paper filter for my car. Im now about to do its 3rd service so I am starting to save. Id keep the KnN for the lifetime of the car. They come with a 1,000,000 mile warrenty.
(Im talking about the induction kit not the replacement panel if that matters)

so its been on for 30K miles? ... see what put me off is i was doing an engine swap many moons ago on an astra and at the same time put on a K&N ... the intake like everything was scrubbed till it was spotless, after about 8K miles there was a build up of fine dirt on the whole inlet, it isn't from the crank vent or anything it could only have came through the K&N ... i'm not sure if dirt that fine could have damaged the engine but i wasn't keen on it none the less, a friend had the exact same thing happen on a pug 106 as such i've never used K&N again.

I can see why people use these things the noise they make is very appealing in my opinion!

[LuS1fer]

Kenny-Mack said:

off_again said:

To be fair, it really depends on what type of car and what type of tune it runs. For example, a modern car with a powerful ECU will automatically sense airflow and change the flow maps and injection settings, so a freer air filter is unlikely to make any difference at all. In some cases it might even make it worse!

surely if the ECU detects more air flow and adjusts the fuelling the car will run better with a better filter? rather than run crap?

Most computers have tables within a certain range. If it falls outside these ranges, it has no reference so can either run weak or resort to limp-home mode. Supplying extra fuel also depends on the pressure and capacity of the fuel pump and regulator.

[pringle1988]

Kenny-Mack said:

pringle1988 said:

Kenny-Mack said:

isn't a standard filter about £5 from a motor factors and a K&N one about £60?

seems a long way to go to save money 12 services? ... so assuming your changing your paper filter every 10K miles your keeping the same K&N filter on for more than 120K Miles?

I find it hard to believe a K&N filter will save you money over a paper filter.

I got my KnN second hand for £45 after going into a motorist discount store and seeing that it is £22 for a paper filter for my car. Im now about to do its 3rd service so I am starting to save. Id keep the KnN for the lifetime of the car. They come with a 1,000,000 mile warrenty.
(Im talking about the induction kit not the replacement panel if that matters)

so its been on for 30K miles? ... see what put me off is i was doing an engine swap many moons ago on an astra and at the same time put on a K&N ... the intake like everything was scrubbed till it was spotless, after about 8K miles there was a build up of fine dirt on the whole inlet, it isn't from the crank vent or anything it could only have came through the K&N ... i'm not sure if dirt that fine could have damaged the engine but i wasn't keen on it none the less, a friend had the exact same thing happen on a pug 106 as such i've never used K&N again.

I can see why people use these things the noise they make is very appealing in my opinion!

Yeah about 30k now. That advice is good to know, I might go and do some research on them. Thanks

[dudleybloke]

just nick a pair of your moms tights and use that as a filter. proper old skool tuning!

[Merp]

The K&N 57i was tested on numerous rolling roads in a Fiesta ST giving an additional 8-10BHP.
I saw the "scoreboard" at jamsport after they had the Owners club there and a standard ST with a K&N57i reached 159bhp [Standard running at 150...ish]

[Kenny-Mack]

pringle1988 said:

Yeah about 30k now. That advice is good to know, I might go and do some research on them. Thanks

Do us a favor just have a swab around the piping behind the filter and tell me if there is fine dirt / dust in there, as said in my experience there was that after just 8K miles and i'd like to know if the ones i have experienced have just been a few lemons.

Report back

[minimanAC]

A good mate of mine fitted a Pipercross filter to his 182, he already had a decat milltek and then went on the dyno. The Pipercross ended up making less power than the stock filter when they compared it back to back, the only thing gained was the noise.

[Kenny-Mack]

LuS1fer said:

Most computers have tables within a certain range. If it falls outside these ranges, it has no reference so can either run weak or resort to limp-home mode. Supplying extra fuel also depends on the pressure and capacity of the fuel pump and regulator.

Yeah your sort of right, i do a bit of mapping on cars, in fact just recently sold all my kit because i'd lost interest in doing it so i've tinkered with all the different settings on quite a few ECU's and still get roped into it for friends quite often.

My point was kind of 2 fold, firstly if its a "powerful" ECU it should handle the extra masses of air flow, which you say they cannnot. Secondly the airflow difference from an air filter is going to be minimal and any ECU can handle it, no panel filter will cause any issues with any ECU. To put in perspective many factory ECU's can handle a lot more air than the engine was originally mapped for - speak to the MR2 V6 lads that have been strapping superchargers to the engines with no other modifications to the ECU quite impressive to be honest, although not something i'd be brave enough to try with a stock ECU.

Issues you see with aftermarket gauze filters come from the oil in the filter which can, but may not always, gunk up the AFM hot wire (there are ways round this, and its only an issue if you have an AFM not a MAP sensor)

The other reason some engines throw a wobbly is because the air box has been ditched, and an open filter has been put in place - what happens here is the air filter sucks in HOT air from the engine, this throws the AIT (Air Intake Temp) sensor values out of the ranges (as you mentioned before AKA parameters) because the temp is higher than ever expected the air is seen as much less dense by the AIT but the AFM will be feeding high values in for air flow - this causes many ECU's to flake out, particularly vauxhall ones - the solution for the vauxhall lads was to go back to enclosed induction kits, or stick with the panel filter upgrades.

For me i think i would need some convincing to use an open cotton filter again, the main advantage of these is noise, that and you often remove half a ton of airbox making the engine bay an easier place to work on and usually cleaner looking too, Another thing which has not been mentioned yet and really should be is that because these filters growl as you floor it you WILL use the throttle a bit more openly and as such your fuel economy will suffer - its more of a human nature issue than the filter affecting your fuelling but the result is the same.

For me i just serviced my Audi and i just got a paper filter from the motor factors it was like £4.80, i doubt i would run a K&N filter for 100K miles to save £10 or whatever because no filter is going to be in any fit state to filter or to flow air after that long - its not a matter of warranty its just going to be bunged up and trashed.

HTH

[SoliD]

Would say mainly placebo effect from my POV. Definitely improved the sound on my V6 but the heatsoak in the summer was horrible so I got a pipercross and relocated it into the wing which is much better but whether it has improved hp in any way shape or form is a different matter.

[Ry_B]

All my cars that I have owned have had "induction kits" fitted, I've had K+N, Pipercross + AEM. Oh and Apex aswell. They make a glorious sound and even if they make you loose a few bhp they make the drive more involving which is definitely worth loosing a few bhp for.

What's best going 0.1 second quicker to 100mph or having twice the fun?