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Discussion Starter · #1 ·
Which filter is the best for our caymans? What do you guys recommend? K&N doesn't state any HP/TQ gains but EVOMS state theirs give 6-8hp/tq.

Please advise me as i'm very close to pull the trigger on a k&n filter.
 

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Doc,

Just be aware that I expect that your dealer, as with all dealers in this region, will tell you that your warranty is invalid if it is still fitted at servicing time....so would suggest making sure you remove it for any trip to the dealer.

Personally I'd stick with OEM over an cotton oiled filter. I like the EVOMS filter construction, look and good comments on here, BMC has a good name in the business and K&N is...well much cheaper than the others.

Whichever way you go just make sure you clean it every couple of months especially after any sand storms and only very very lightly oil it.
 

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I'd suggest keeping the standard filter in the car unless you plan to change the oil every 5K miles. It's risk vs reward, albeit a 2-3% reward.
 

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Which filter is the best for our caymans? What do you guys recommend? K&N doesn't state any HP/TQ gains but EVOMS state theirs give 6-8hp/tq.

Please advise me as i'm very close to pull the trigger on a k&n filter.
2 quick comments -

one porsche air-cooled mechanic said the K&N would 'catch the larger rocks' ... not exactly sure where he's coming from on that; my wife's subaru is nearing 200K miles w/o using much oil - used a K&N its whole life. and we live some miles up gravel roads ...

I use a K&N in my '06 CS and I'm thinking of going back to the stocker ... the neck on the K&N is flexible to the extent that it's really (!) difficult to install AND get the clamp installed at the same time. i.e. the neck can bend to conform to the mount ... and conform its way right off too ...

being one assembly w/ stiffer mounting flange, the stocker is much easier. twice now it's taken me about 1/2 hour to install that K&N and I have small hands.

ymmv,

-PM.
 

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one porsche air-cooled mechanic said the K&N would 'catch the larger rocks' ... not exactly sure where he's coming from on that; my wife's subaru is nearing 200K miles w/o using much oil - used a K&N its whole life. and we live some miles up gravel roads ...
It seems he may have been talking about the reduction in filtration that the K&N offers. Basically the holes in the filter material are bigger than on a paper filter, otherwise how does it flow more air....

There's lots of arguements for and against aftermarket filters.
 

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my mechanic at the dealer advised strongly against oiled filters. Apparently there is a sensor that can get a film of oil on it. The sensor does heat up to burn the oil off, but some residue is left. He said that over the long term the ensor would malfunction.
 

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my mechanic at the dealer advised strongly against oiled filters. Apparently there is a sensor that can get a film of oil on it. The sensor does heat up to burn the oil off, but some residue is left. He said that over the long term the ensor would malfunction.
What he is referring to is the MAF, MAP or MAS (Different names for different companies), which are basically the same and use heated wires or elements to establish the air flow (Sometimes pressure and temp) through the intake system.

There are lots of ways this particular issue can be cut, and there is a possibility that the oil could cause a higher than normal temperature spot on the sensor elements causing premature failures, but how can one prove this??
The other part is that if only a light coating of oil is used then how much can be sucked through and is it enough to cause damage, again who knows.

In my days of Audi tuning there were lots of thoughts on it, but in my honest opinion most of the failures were simply because the Bosch MAF's were/are unrealiable to say the least.

Japanese tuners use a lot of stanless steel filters and I have one on my A3, and there are similar opinions on them, yet I've had no issues in the 60k+ kms I've had mine on.

In a lot of cases in regards to filter and how much "dirt" it lets through and the potential long term damage it could do, most of us will never know because we won't keep the cars that long. One thing that is certain is the the OEM paper filter has been tested and is proven to provide longevity of the engine when replaced periodically.
 

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I would agree with the recommendation for using the OEM paper filter. But I can’t understand why posters like Dunebasher and CJP80 offer advise to “clean it every couple of months” when the BMC specifically states NOT to clean/recharge less than 15000 miles based on environmental conditions. Furthermore, BMC states that the accumulated dirt actually aids in the filtering efficacy. Apparently, the filter media is so porous that the dirt has minimal impact on air flow.
-Stevie
 

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I would agree with the recommendation for using the OEM paper filter. But I can’t understand why posters like Dunebasher and CJP80 offer advise to “clean it every couple of months” when the BMC specifically states NOT to clean/recharge less than 15000 miles based on environmental conditions. Furthermore, BMC states that the accumulated dirt actually aids in the filtering efficacy. Apparently, the filter media is so porous that the dirt has minimal impact on air flow.
-Stevie
Not sure where that interval comes from Stevie, but the BMC website states in the FAQ section;
We advise regeneration every 15000 km to guarantee long lasting performance and duration. This value can change based on the environmental conditions the car is used in (e.g. non tarred roads, presence of pollen, dust,…).
That's 15,000 kms not miles (same as 9,000 miles), and is a maximum not a minimum recommendation and even so says it should be adjusted based on conditions, but still the EVOMS is a lot less at around 5000-10000 miles. K&N I think is much higher which would be crazy for this region. Filter maintennace is not a hard fast rule and is a guide only and should be adapted accordingly.
I think if you spent good money on hp gains then you'd be silly not to maintain those gains, which in this case is by cleaning teh filter regularly, otherwise why not just stick with the OEM paper filter?!

The reason I say I would clean a cotton filter every couple of months is because the lightweight dust we get here covers the inside of our cars on a weekly basis and so that same dust will stick to the oil and clog quicker than a paper element so to maintain the potential gains offered by the cotton filter I feel you'd want to clean it every couple of months...at least here anyway.

If you see how shotblasted the front of cars in Saudi are after just a year or so and see the insdie of my cars after a sand storm strikes I think you'd understand.

But it is just my opinion and I would definately clean it every few months based on the local conditions.
 

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I didn't mention filter cleaning schedules...I did however recommend regular oil changes as the BMC filter lets a lot more particulate matter through into the engine than the standard paper one.

Wouldn't worry about MAF fouling, yet to hear of it being a problem on these cars.
 

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If you do a search you will find oil fouling the MAF is a documented problem, usually from more than just one source.
 

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I run the OEM air filter on my '07 CS. I ran a K&N on my '02 Mercury Mountaineer for years and I recall that the literature that came with it claimed the filter worked BETTER with time. The recommended cleaning was every 50K miles.

FWIW the Merc has 180K miles on it and shows no signs of giving up...yet
 

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Furthermore, BMC states that the accumulated dirt actually aids in the filtering efficacy. Apparently, the filter media is so porous that the dirt has minimal impact on air flow.
-Stevie
Isn't that just saying, as the filter becomes more clogged it reduces the particle flow further? Oh, and reduces the airflow, negating the reason for it's installation in the first place!
 

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What I am about to say is general filtration theory. I am not talking about anyone filter or brand. The cotton filters are what in known as a combination of depth filtration and coalescent filter. The oil is a coalescent agent (atracts dust, and keeps it) The dirt is trapped in a tortous path through the filter. When the filter is fresh clean the capture efficiency is actually as it lowest. As it accumulates particles the capture efficiency improves and less dirt flows through. The pool water filters are depth filtrationr for water. The fiberglass media it just a structural shape to hold diatomaceus earth (DE). The DE is actually does all the filtration. As the media gets dirtier the pressure drop increases, and the capture efficiency gets better, as long as there is not a crack on the DE cake.

I have seen comments by Scott Slauson saying not to bother with the cotton media filters, to stick to the original paper filters. I am just passing along his comments, but he has a lot of actual direct experience on car performance. I do not, I just drive them.
 

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It seems he may have been talking about the reduction in filtration that the K&N offers. Basically the holes in the filter material are bigger than on a paper filter, otherwise how does it flow more air....

There's lots of arguements for and against aftermarket filters.
I bought a '95 M3 new. Put a K&N on it after break-in miles and used it until the day I sold it last May. Removing the filter and checking the inside of the intake pipe is a good way to find fine dust if a filter is leaking or not working right. None found ever with this one. No ill effects in 50,000 miles of mostly track driving.

That's not to say that the one for the Cayman is as good. The mounting problems alone make me want to stay away. Another thing that does is the price...$250? I don't think so.

Be careful oiling up those things. If you overdo it, they MAF sensor will get coated with oil and won't work so great anymore. Possible but difficult to clean.
 

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Which filter is the best for our caymans? What do you guys recommend? K&N doesn't state any HP/TQ gains but EVOMS state theirs give 6-8hp/tq.

Please advise me as i'm very close to pull the trigger on a k&n filter.
The HP gains from a plain ol filter (K&N, BMC), if any, should be very similar. I have the BMC and have no problems to date with it. Plus, it fit perfectly every time I swapped it. If I wanted to thin some skin off my knuckles, I'd pick up one of those old K&N's ;)
 

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Discussion Starter · #17 ·
Seems like i'm going to skip it and stick to OEM.

I remember I had K&N on my bimmer, put too much oil to clean it and it messed up my MAF.
 

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I bought a '95 M3 new. Put a K&N on it after break-in miles and used it until the day I sold it last May. Removing the filter and checking the inside of the intake pipe is a good way to find fine dust if a filter is leaking or not working right. None found ever with this one. No ill effects in 50,000 miles of mostly track driving.

That's not to say that the one for the Cayman is as good. The mounting problems alone make me want to stay away. Another thing that does is the price...$250? I don't think so.

Be careful oiling up those things. If you overdo it, they MAF sensor will get coated with oil and won't work so great anymore. Possible but difficult to clean.
It's actually on special at 50.xx + S/H :D

The horror stories about MAF getting oiled up usually come down to over-oiling the filter (unfortunately yes, a user error). Properly taken care of, these filters outperform the OE parts in any given aspect outside of environmental protection.
 

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As an FYI, this has been discussed at length (and I mean a LOT) on this site before.
Quick conclusion: Yes, some risks as mentioned exist, in practice correct use results in no problems. I doubt you will find any member here who installed one and ended with a problem. I ran the EVO filter for 3 years. - all good. You just have to clean it every 5000kms or so.
 
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