Air Filters, How good are they, Really????

[FrankS]

I was advised against using oiled Sponge or Cloth and Gauze air filters, I had used a K&N Filter on my Ford Falcon GT (5.4 DOHC V8, 310Kw around 400hp) and got a noticable increase in power and economy. I figured these type filters would be great on my Disco. I was directed to a web site re: Testing Air Filters http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm it sure opened my eyes, never too old to learn, check it out, Regards Frank.

[AAXD]

I have a K&N in my range rover and I really didn't notice much performance change vs the paper filter. I think I'll stick with stock on my disco. Time for a change anyway.

[me.guevara]

Wow! Great find Frank - thanks!

I look forward to the reaction from the folk using some of the aftermarket filters included in the testing...

Cheers,

[FrankS]

Originally Posted by AAXD

I have a K&N in my range rover and I really didn't notice much performance change vs the paper filter. I think I'll stick with stock on my disco. Time for a change anyway.

Did you check out the Filter Test web-site, Regards Frank.

[Disco]

I'll just stick to K&N.

[FrankS]

Originally Posted by Disco

Hmmm, Is this another 'baited' question like the winch thread? Because if it is, I'll tell you some facts of life. Simply changing you air filter, and I don't care which one you want to use, will not give you more than 1 extra horsepower, maybe 2 but I doubt it. It may well have given you slightly more on your high performance vehicle, but it will do 'jack shit' on your Disco.

Disco, not a baited question, I was going to fit a K&N filter to the Disco, I got a noticable gain with the GT and I figured my little 3.5 could use all the help it can get. I have fitted a set of extractors and a 2 1/2" free flowing exhaust, and I'm in the process of installing a Snorkel now, I am having a Unichip fitted by Graeme Cooper at St. Peters in Sydney. I was advised by a few people that should know to steer clear of oiled Sponge or cloth air Filters, even with a Donaldson Pre cleaner fitted. A mate who competes in off road racing sent me the web site posted above, I was shocked to see how much dust was not trapped by these type filters, read the site, draw your own conclusions, and please don't shoot the messenger. Seems to be a fairly comprehensive test, maybe the manufacturers of these type filters could provide some info, Regards Frank.

[Disco]

FWIW, with the upgrades you have in mind, I'd simply stick with the factory paper filter as it's more than adequate. However, if your looking to increase your air flow because of high performance mods, then I'd look around.

[FrankS]

Originally Posted by Disco

FWIW, with the upgrades you have in mind, I'd simply stick with the factory paper filter as it's more than adequate. However, if your looking to increase your air flow because of high performance mods, then I'd look around.

Disco, I have the round air filter canister with the trumpet tube sticking into the area where I want to put the second battery. I am going to make a larger diameter canister and move it further towards the firewall, relocate the coil and have the flex tube from the snorkel come into the front of the canister, I will be using the paper filter from my GT (it still has the K&N), it is cone shaped with the front having a half ball shaped top to the cone, reasonably priced and flows enouigh air for 290kw/5.4L, should do the trick. Regards Frank.

[Disco]

Sounds good. Do you have room to move back towards the firewall with the windscreen washer bottle being where it is?

[FrankS]

Originally Posted by Disco

Sounds good. Do you have room to move back towards the firewall with the windscreen washer bottle being where it is?

Disco, I have removed Washer Bottle and am going to replace it with 2 slimmer, smaller aftermarket bottles, I will take some pics and post them when I'm finished, Regards Frank.

[Funrover]

WOW!!!! That's pretty cool!!!! I still noticed some help with the K&N!!! So i will continue to use mine!!

[Muddy Oval]

K&N is great on a heavily modded engine- where high flow counts and fractions of a second mean win or lose. I run them on my B/GT race car because for the small size I can fit, they flow better than paper. For a Discovery, why take in the dust and risk the electronics? Plenty of people have ruined sensors with oiled filters when the paper filter can flow as much air as a Disco will ever ask for. The panel filter in a Disco can be 25% clogged and still flow as much as the Disco will ask for.

[keptin]

I bought my K&N filter for my DII years ago, havent had any problems, only good things to come from it. There was a thread on here a while back about owners blowing thier MAF sensors from it; oh well, sucks for them....im 100% pro-K&N.

[Adam in NYC USA]

Originally Posted by FrankS

I was advised against using oiled Sponge or Cloth and Gauze air filters, I had used a K&N Filter on my Ford Falcon GT (5.4 DOHC V8, 310Kw around 400hp) and got a noticable increase in power and economy. I figured these type filters would be great on my Disco. I was directed to a web site re: Testing Air Filters http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm it sure opened my eyes, never too old to learn, check it out, Regards .

I think it would help if you have the original URL of that information. It looks cooked, too well cooked, and PowerPointed to death. Last I checked, it was at a website promoting some elses product.

Hmmm.

Okay, looking at this "information", so if I use a K&N airfilter, it lets six grams of test material (dirt) thru.

Where does the dirt go anyway, people?

Think about it.

Let me use my 1996 fuel injected engine as an example.

You are feeding atmospheric air, with all types of particulate matter, into a Land Rover internal combustion engine. If you have the original airbox, it first goes past that grimey jack into a trumpet. You then filter it. The filtered air then goes past the MAF sensor and thru the intake into the plenum. It then gets divided into servral other trumpets into the intake manifold where it get sprayed with fuel from the fuel injectors. There are several opportunities where post-filtered dirt would collect. That is why there is that intaker cleaner spray (Ohh....... )

Finally, it goes thru the intake manifold and into the combustion chamber.

Not why do I mention this circuitous route? Because anything that has made it so far past the filter gets it in the combustion chamber. It gets incinerated. If it is of any metallic nature, it would have stuck anywhere prior to the combustion chamber. The engine block is aluminium, by the way.

So why do I mention this?

If you are really this worried about it, then don't change anything.

If you need or want more power, and invest in expensive stuff like an aftermarket supercharger or turbocharger, I would want to keep my investment. That would include a spin-down timer and a better airfilter.

[Muddy Oval]

define 'better' More flow or less particulates? For my Disco which I want to last as long as possible, I'd say less particulates... for the race engine that only gets 300 miles a year, I'd say more flow. Besides, nobody has ANY evidence that the size of the stock paper panel isn't sufficient for a stock engine.