K&N Filter - breath of fresh air? or 40 a day?
Discussion
having fitted one of these last yeasr I was rather perplexed by comments on some recent threads about the filter letting large amounts of crud into the engine. I'd not heard this before but the comments seemed to imply its a well known worry. whats the consensus on Pistonheads? is it a useful, safe modification or am i subjecting my poor engine to the automotive equivalent of 2 packs of Marlboros a day?
Hi,
This is an example of what can happen when mis-information gathers momentum across the Internet.
K&N is a large company making a good product (that is a little expensive to put into manufacturer cars). If it were true - I don't think they would be in business.
The filters must be used correctlly and require periodic cleaning and re-oiling with the correct K&N filter oil. Used correctly, thay can last 5 x longer than a paper element. The K&N also improves performance (varies from car to car) and does not clog up (like a paper filter).
A K&N Filter uses depth and surface filtration where as a paper filter is surface only.
We stock K&N Filters for the following Porsche models: Boxster 2.5, 911 3.2, 964, 944 Turbo, 944S, 944S2, 944 8v, 924S and 968. All are priced at £49.95 inc with free delivery.
Regards,
Andrew
www.promaxmotorsport.com
This is an example of what can happen when mis-information gathers momentum across the Internet.
K&N is a large company making a good product (that is a little expensive to put into manufacturer cars). If it were true - I don't think they would be in business.
The filters must be used correctlly and require periodic cleaning and re-oiling with the correct K&N filter oil. Used correctly, thay can last 5 x longer than a paper element. The K&N also improves performance (varies from car to car) and does not clog up (like a paper filter).
A K&N Filter uses depth and surface filtration where as a paper filter is surface only.
We stock K&N Filters for the following Porsche models: Boxster 2.5, 911 3.2, 964, 944 Turbo, 944S, 944S2, 944 8v, 924S and 968. All are priced at £49.95 inc with free delivery.
Regards,
Andrew
www.promaxmotorsport.com
People on Rennlist seem to go one of two ways - either get a BMC panel filter or change the standard paper filter regularly. Avoid K&N and any of the induction kits (i think because the K&N lets more crud through whereas the induction kits breathe in the hottest air in the engine bay).
Hi softinthehead - I asked this very question when I bought my 993tt. The replies to my post, and the link (near the end of the thread) to another thread where the technical merits versus consequences are discussed, finally convinced me not to bother.
I just change the paper filter element regularly.
Go see this thread and the USA site of tests, then come back and tell me what YOU think. If you accept that the K&Ns do let through more crud, then I suppose it is just an issue of whether you envisage keeping the car long term and engine longevity is an issue.
www.pistonheads.com/gassing/topic.asp?t=118532&f=48&h=0&hw=air+filter+dirt
I just change the paper filter element regularly.
Go see this thread and the USA site of tests, then come back and tell me what YOU think. If you accept that the K&Ns do let through more crud, then I suppose it is just an issue of whether you envisage keeping the car long term and engine longevity is an issue.
www.pistonheads.com/gassing/topic.asp?t=118532&f=48&h=0&hw=air+filter+dirt
sweetea said:The advantage of this is that the amount of air that can flow through a K&N remains more or less constant (unless you don't clean it) whereas a paper filter will gradually reduce the flow over time.
The filters must be used correctlly and require periodic cleaning and re-oiling with the correct K&N filter oil. Used correctly, thay can last 5 x longer than a paper element. The K&N also improves performance (varies from car to car) and does not clog up (like a paper filter).
A K&N Filter uses depth and surface filtration where as a paper filter is surface only.
One thing you should be conscious of, when using any "wet" filter (those that require oiling) is that if over-oiled, excess oil can contaminate the MAF sensor further upstream in the inlet tract.
I've used a foam ITG filter (oiled) on my Westfield for 10yrs now, cleaning from inside out then re-oiling, stripped engine 3 times for upgrade work, and never seen anything untoward in terms of foreign objects that should have been kept out. I don't run a MAF on that though, throttle position is done via a throttle-pot.
Like everything, you'll always hear of the odd filter that isn't quite installed correctly (ie sealed properly in an airbox) that "perhaps" has contributed towards a particle getting thro'.
I've used a foam ITG filter (oiled) on my Westfield for 10yrs now, cleaning from inside out then re-oiling, stripped engine 3 times for upgrade work, and never seen anything untoward in terms of foreign objects that should have been kept out. I don't run a MAF on that though, throttle position is done via a throttle-pot.
Like everything, you'll always hear of the odd filter that isn't quite installed correctly (ie sealed properly in an airbox) that "perhaps" has contributed towards a particle getting thro'.
softinthehead said:
hah! see what I mean? two posts, poles apart!
andrew, I bought my filter from you but didnt know anything about filter oil - if I keep the filter on, how often does it need cleaning/refreshing (i.e with an annual/12k service or more often?) and is it an easy process?
Hi,
All the info was supplied with the filter (packaging and inserts). It should be oiled at least every 12,000 miles.
All,
A K&N filter will only let more cantaminants through if it is not used correctly. If that was not the case - K&N would be up to their necks in lawsuits.
As a Performance Tuner and Supplier - we know what works and what does not. K&N Panel Filters will increase peformance as they flow more air. When combined with a suitable performance enhancing chip, this is very beneficial (such as with the ProMAX Performance Chip).
One of our most popular and cost effective upgrades is the 968 ProMAX Performance Chip and K&N Panel Filter = +22bhp and +27Nm torque (some have achieved more) - varies from car to car. The K&N Filter must be used correctly though.
Regards,
Andrew
If it were that easy to get performance without any compromises by simply putting in a K&N why don't car manufacturers do it?
I've seen other tests where these do let through more particulates, which is presumably why they offer less resistance and improve breathing. As to the lack of lawsuits, I guess it takes a long time to cause any wear and if the oil is doing its job it will trap the particulates anyway.
DanH said:
If it were that easy to get performance without any compromises by simply putting in a K&N why don't car manufacturers do it?
Purely cost....paper filter = 50p-£1 per unit versus £40-50 for a K&N...okay, the numbers are't exact, but the differences are of that sort of magnetude. Having been in manufacturing engineering (long distant past) ever 10th of a cent UMC does count to these guys.
DanH said:
I've seen other tests where these do let through more particulates, which is presumably why they offer less resistance and improve breathing.
Okay, not in a position to argue that one without seeing data from an independant tester. I always remember back to David Vizards book on tuning the good-ol' A-Series and him testing breathing and exhaust components, and there's significant gains to be had. The theory follows for any internal combustion engine....taking your point to it's logical conclusion, the best filter is a solid plastic plate over the inlet tract
(sorry, being flippant) DanH said:
As to the lack of lawsuits, I guess it takes a long time to cause any wear and if the oil is doing its job it will trap the particulates anyway.
Presumably you mean the air filter oil, not engine oil/filter!!
spenny_b said:You also couldn't expect a customer to be examining and reoiling their air filter on a regular basis.
If it were that easy to get performance without any compromises by simply putting in a K&N why don't car manufacturers do it?
Purely cost....paper filter = 50p-£1 per unit versus £40-50 for a K&N...okay, the numbers are't exact, but the differences are of that sort of magnetude. Having been in manufacturing engineering (long distant past) ever 10th of a cent UMC does count to these guys.
spenny_b said:
As to the lack of lawsuits, I guess it takes a long time to cause any wear and if the oil is doing its job it will trap the particulates anyway.
Presumably you mean the air filter oil, not engine oil/filter!!
No I don't. One of the purposes of the oil is to capture and trap particles which then get filtered out in the oil filter.
As to reoiling filters - you need to do this about as often as you need to change a paper filter, so I don't see any sense in that argument.
On the cost front thats pretty silly too as you can buy a flat K&N filter to go in where the standard manufacturer ones go for not a lot. Its only when you buy cone filters with mounting gubbins to help suck hot air in fom the engine bay that costs escalate. If it really gave 5 bhp with no downsides I'm sure they'd find the money - makes more sense than carbon fibre bonnets etc!
If I have time I'll try to dig up the thread I was referring to.
sweetea said:
hah! see what I mean? two posts, poles apart!
andrew, I bought my filter from you but didnt know anything about filter oil - if I keep the filter on, how often does it need cleaning/refreshing (i.e with an annual/12k service or more often?) and is it an easy process?
Hi,
All the info was supplied with the filter (packaging and inserts). It should be oiled at least every 12,000 miles.
Andrew
thanks for that. i arranged for the filter to go straight to the garage so never saw the instructions. I'm sure Crispin has seen them before however, adn will know what to do come next service time
DanH said:
As to the lack of lawsuits, I guess it takes a long time to cause any wear and if the oil is doing its job it will trap the particulates anyway.
Presumably you mean the air filter oil, not engine oil/filter!!
No I don't. One of the purposes of the oil is to capture and trap particles which then get filtered out in the oil filter.
But for any particles let through by the air filter to make it into the engine oil, they will already have had a field day with the valve seats and then have to get down past the compression and oil scraper rings on the pistons - not good news for the cylinder bores obviously!
softinthehead said:
All the info was supplied with the filter (packaging and inserts). It should be oiled at least every 12,000 miles.
Andrew
thanks for that. i arranged for the filter to go straight to the garage so never saw the instructions. I'm sure Crispin has seen them before however, adn will know what to do come next service time
In the past I have always received K&N filter elements ready oiled so they have been a straight swap.
spenny_b said:
One thing you should be conscious of, when using any "wet" filter (those that require oiling) is that if over-oiled, excess oil can contaminate the MAF sensor further upstream in the inlet tract.
.
My car has a K+N fitted by a PO. don't know when so I guess I'd better clean it and oil it.
how much is too much and how do I judge the correct amount?
Cheers
I installed a K&N around 2k ago. Last week i took the MAF out to check to see if it was soiled, i used a cotton bud to gently wipe the electrodes and guess what, the bud was as clean as a whistle. I expected it to be a little oily after all ive read but not so.
The info i got with the filter states it requires cleaning and oiling at 50,000 miles not 12,000 or when the colour starts to fade.
My advice is buy it new and avoid cleaning and oiling it if you can as they come pre oiled with the correct amount of oil and they are very easily over oiled which could lead to the maf becoming soiled.
>> Edited by t urbo on Thursday 17th November 15:50
The info i got with the filter states it requires cleaning and oiling at 50,000 miles not 12,000 or when the colour starts to fade.
My advice is buy it new and avoid cleaning and oiling it if you can as they come pre oiled with the correct amount of oil and they are very easily over oiled which could lead to the maf becoming soiled.
>> Edited by t urbo on Thursday 17th November 15:50
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