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I have used dry filters for years, I see no benefit in having a wet filter like K&N for example.
The only benefit, is that you can reuse the wet filter over and over again versus dry.
Always dry on any car with a hot wire / hot film MAF. I have personally had a brand new K&N filter (one that I did not over-oil myself after washing) destroy a good MAF on my 928 from the small and now oily and sticky dust particles that get through the filter and/or small oil droplets hitting and coating the hot platinum wire, and I've heard of the same happening on several other cars. Oiled filters may be OK for older cars that have a mechanical VAF, but they have no benefits whatsoever over dry ones.
2010 Ford G6E Turbo / 2013 C63 Coupe - AMG Performance Pack
In summary, and based on post 4 from the below link, K & N has the higher capacity, with the pro dry s with the better filtration. The pro guard (oiled filter) was best overall but I don't think we can get these for our cars?
I've used K & N filters on every car I've had in the last 25 years and never had any issues. I clean and re-oil annually. Yet to decide on a filter for the C63 though.
Last edited by juggernaut1; Mar 20, 2019 at 05:15 PM.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
It’s a well known fact that oiled filters create MAF problems on our cars. Fact.
You guys use use whatever you want. I know that I always want better filtration vs the extra 1/2hp you gain from using something that lets more junk through.
2010 Ford G6E Turbo / 2013 C63 Coupe - AMG Performance Pack
Originally Posted by BLKROKT
You guys use use whatever you want. I know that I always want better filtration vs the extra 1/2hp you gain from using something that lets more junk through.
Are you guys serious
So....you use the stock filter then for better filtration rather than the 1/2 hp improvement an aftermarket filter provides?
The take away is that an aftermarket filter is very likely to result in poorer filtration than your OEM filter. Modding your car to make more hp is likely to result in increased wear. Tracking your car is also likely to result in increased wear. The point is there are many things car enthusiasts like us do that are detrimental to longevity and accelerate wear. In the scheme of things I don't think an aftermarket filter is a big risk since I've owned a modded car for 13 years with a K & N filter without issue.
Last edited by juggernaut1; Mar 20, 2019 at 07:33 PM.
All other things being equal (i.e. same air pressure and filter surface area), higher air flow ALWAYS comes at the expense of filtration ability (it's a linear relationship). The larger the void ratio of the filtration medium, the larger the solid particles that can pass through it. If a given filter can flow 100L of air per minute and allow 5µm and smaller particles to pass through, then a filter of the same size than can flow 200L of air per minute will allow 10µm and smaller particles to pass through. And, contrary to what the company claims, K&Ns actually flow worse than modern OEM paper filters, especially once they start getting clogged up.
If you really want to know how a K&N compares to an OEM paper filter (and I am talking just about air flow and filtration efficiency, not the fact that it will also bugger up your MAF as well as shorten the life of your engine), here's a rather conclusive article on the subject: https://www.sciencedirect.com/scienc...12017316301475.
I ran into the same issues with my old turbocharged NX when I was using a ford cobra MAF because of the larger diameter, but still a hotwire MAF and it always caused issues. Started using an HKS pro dry filter and it was fine.
I think the AFE Pro Dry is the best compromise for maintenance/reliability/flow
Kind of understand the predicament as a balance between air flow, filtration and lifespan/ease of maintenance.
AFE pro dry was the best balance for me. Still acceptable for filtration, plenty of air flow, and I'm okay with cleaning out the filters a little bit more often. I won't bother with wet because of the proximity of the MAFs to the filter housing
2010 Ford G6E Turbo / 2013 C63 Coupe - AMG Performance Pack
Pretty sure the 31-10154 is for a single filter, check out part 31-10195 for the pair of filters you will need.
For what its worth, I ended up ordering the AFE's based on the general consensus. I then order the Eurocharged v7 tune through this site and out of curiosity asked for a filter recommendation. The recommendation was the K & N filters. I mentioned that I had ordered the AFE's and whether I should cancel the order and get the K & N's, to which I was advised just to keep the AFE's. I can't imagine Eurocharged recommending the K & N's if they were problematic to the MAF's - but there you go.
Oiled filters will cause issues with the MAF.
Now, the issues won't be severe enough to where a code and a check engine light come on, but that doesn't mean that the air measurement won't be affected and you won't have weird AFR swings, which you may or not care about, or you may or not log your car and wonder what the hell are those.
As far as accelerated wear, I agree that the accelerated wear can be there for high flow filters. Bit there are several situations:
For my Subaru, I use a AEM Dryflow filter. Now for that car, you don't have to retain the OEM Form factor of the filter. So I am using a cone style filter that has more area than the factory rectangle. Also, the factory intake routing is convoluted and the intake is a cold air style, so that's where the gains come from.
Even so, I am prepared to admit that more dirt was not filtered. I have been running this for 50 K miles on the car and haven't lost compression yet, so chances are it's going to be ok.
All other things being equal (i.e. same air pressure and filter surface area), higher air flow ALWAYS comes at the expense of filtration ability (it's a linear relationship). The larger the void ratio of the filtration medium, the larger the solid particles that can pass through it. If a given filter can flow 100L of air per minute and allow 5µm and smaller particles to pass through, then a filter of the same size than can flow 200L of air per minute will allow 10µm and smaller particles to pass through. And, contrary to what the company claims, K&Ns actually flow worse than modern OEM paper filters, especially once they start getting clogged up.
If you really want to know how a K&N compares to an OEM paper filter (and I am talking just about air flow and filtration efficiency, not the fact that it will also bugger up your MAF as well as shorten the life of your engine), here's a rather conclusive article on the subject: https://www.sciencedirect.com/scienc...12017316301475.
^Thank you. I see so many people get hung up on the effectiveness of their air filters as if their engine must breath completely purified air, void of microscopic dust particulates or other contaminants, in order to perform well...
This is a high-compression internal combustion engine, boys: Any dust particles that happen to get past the air filter will most assuredly get incinerated in the combustion chamber, and if not, then incinerated in the catalytic converter, and then finally blasted out the tail pile shortly thereafter (unless you drive like a Nancy all the time)... If you're looking to maximize performance, then FLOW should really be your primary concern. Filtration efficacy and performance (i.e. flow) are inversely proportional, unfortunately.
Well - dust particles are like sandpaper to the cylinder bores. The more the number and the larger the dust particles your engine ingests, the faster you'll end up scoring the block. Most solid particles (dust) don't incinerate at the temperatures created by gasoline combustion, and besides, the piston has already moved up on the compression stroke where said particles have mechanically scraped the cylinder bore before ignition takes place.
I linked the article above as it demonstrates that a K&N does not flow any better than an OEM paper filter - in fact it actually flows worse while allowing even bigger particles to get through to the engine. The paper filters generally have a larger surface area (more pleats) than a K&N and will thus flow more without sacrificing filtration efficiency. As for maximizing the air flow, if an engine consumes 50,000 Lpm at WOT at redline, there is zero benefit to using a filter that can flow 80,000 Lpm vs. one that can flow 50,001 Lpm.
Not arguing your logic, but unless you've run a super open foam filter (e.g. Pipercross) for the life of the car or you live in a very windy, arid, desert/sandy location (middle east, SW U.S., etc.) we're talking about microns of contaminant size here, where actual damage is extremely small and any resulting reduction in performance is probably immeasurable. I mean, we have 2+ gal of oil that is circulated through our engines and constantly cools and cleans the cylinder bores before getting transported back to the oil filter and where almost anything of significant size gets trapped. Unless you never change your oil and consistently run a dirty/clogged filter (or just use a ****ty brand) the issue should self-mitigate.
Probably getting existential here, but I just feel like this issue isn't as important as it's always made out to be (look who has to stand financial gain after all: OE/aftermarket part manufacturers maybe?) and that we're more likely to get scoring from other foreign debris such as loose engine block millings, dislodged carbon buildup, and/or rust particles at the top of the stroke, etc. rather than poor intake air quality. I mean if it's that bad, shouldn't we all be walking around wearing dust masks? Yet you see millions of car guys running basically cheese graters on their $10K turbo setups w/o worrying much about dust...
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