Here is an interesting read.

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

 

From what I have seen that is accurate testing although I have normaly seen the Amsoil do much better.

 

there are several other tests that correlate this data. they are why i don't use a k&n. given the miniscule drop across a paper filter (there are several threads here backing that up), why not use the filter that filters best, paper, and just replace it when necessary?

one of these days, i'm going to build an intake that's like the k&n typhoon or the alta, but with a paper filter.....

 

Well the data shows there is certainly less restriction in the K&N, but it also is the least efficient at stopping 'stuff' from getting through. I just recently cleaned and re-oiled my K&N filter from the MINI-Madness CAI and the portion facing the firewall was definatly dirty. Everything else was generally clean, with the exception of a few bugs.

I'm not worried at all. We use K&N filters in the airbox of the race cars and they are subjected to far worse conditions than my car will see (I hope ).

 

I also have no problem with using K&N. I just put one in my MINI and have had one in my other car (Honda Insight) for over 50k miles. The pre-filtered part of the airbox was very dirty but the post-filtered side was squeeky clean. I would think I'd notice a problem with the Insight as any change in efficiency is very noticeable. We still have a lifetime mpg of 64.6 with runs well into the 100-125 mpg range easily obtainable with the A/C off. I don't think there's a problem with dirt getting in.

 

Good read. I don't think we MCS owners have to much to worry about with aftermarket filters though. The intake path has oil all through out it for anything that does get by the filter, especially in the intercooler. motor motor.

 

I think the moral of the story is (with respects to the K&N) is keep it clean and oiled.

 

..........or go to a foam filter like the Alta.


Gobs more surface area available for filtering out the bad stuff.

 

I bet they didn't oil the K&N like it is supposed to be to help in the filtration.

They were all probably just dry filters.


Oh yeah, according to the article, there should be no HP gain at all by swapping to another filter because the stock flows plenty of air. Then WHY do most aftermarket filters show HP gains?....even a drop in K&N?

 

. Then WHY do most aftermarket filters show HP gains?....even a drop in K&N?[/QUOTE]___________________
Manufacturers' claims. I use K&N but I'm not one of those who believe everything they claim. Still, I'll keep using my K&N filter.

 

I'd agree with 04yellowS. I've had both foam and K&N on my cars for years and have never had a problem with K&N. So, these results might actually be believable if they were a credible source or established organization like a consumer reports.

 

In a street environment, a K&N filter should be fine as long as it's kept properly oiled. Realize that the dust buildup actually helps it filter better - to a point - as it closes the air passages somewhat and restricts the finer dust particles from getting through. But it will look nasty enough to make you clean it long before you'll lose airflow efficiency.

Coming from the Jeep world, I won't run one in a dusty environment ever again though. I had a K&N in for a while and had a measurable amount of extremely fine dust in the intake tube after a couple of off-road trips. So it came out and a stock filter went back in. No more dust after that.

FWIW, I have an Alta foam filter on my MINI.

 

Great info on the K&Ns, everyone.

Assuming the K&Ns improve airflow to the MCS, will the MCS ECU be able to adapt to the different airflow characteristics?

I ask this because my experience is mainly with antique British cars. Adding the K&N air filters to a normally aspirated engine sometimes requires a change in the carburetor needles in order to take full advantage of the different airflow.

Same priciple should apply to the MCS. I'd like to assume that the '05 MCS ECU would be able to adapt to the altered air filter, what do you think?

 

The MCS is adaptive so you shouldn't have any problems. Still, if in doubt you can simply disconnect the power from the battery. I don't recall the exact amount of time required. There should be a few threads here on NAM with that information.

AMPR

 

Excellent, thanks.