Air Filter Brand

Al Seim

Well-known member
My old K&N filter on the HP Scirocco is looking a bit frayed, seeing some gaps in the cotton media - maybe just age, maybe somebody used compressed air on it, dunno.

There seem to be several brands now of washable media filters - is K&N still the best, are they all the same, or?

Has anyone seen independent flow test results? Are the washable filters really any better than a new clean paper filter (in terms of flow)?

Thanks in advance!

Al Seim
VW HP Scirocco
 
Tom: Stock airbox.

I did find an interesting test online: http://www.bobistheoilguy.com/airfilter/airtest1.htm

Did not directly answer the question though K&N did win. (And theory suggests that the gap should grow as filter gets dirty, though I'm not seeing a lot of dirt coming out of the filter so this may be moot on a race car)

Interesting that the stock airbox seemed to cause more of a drop than the filter. So I guess that means I'll have to do some instrumented testing......

The filter pressure drop between best and worst looks like it might amount to a quarter of a horsepower on an HP car - not nothing but close.

Al
 
EPrill":1i15gzz3 said:
Anyone tried Green Filters as opposed to K&N?

http://www.greenfilterusa.com/

dyno'd most, no real difference in any... normally "no filter" does the worst on our air filter tests...
i use green in the SM and KN on FP, but would switch either without worry... I don't wash, just replace. That's just my "opinion".... YMMV
 
So are you saying that all "washable cotton media" filters dyno'ed the same or that "all" filters dyno'ed the same?

Al
 
Al Seim":693r71p9 said:
So are you saying that all "washable cotton media" filters dyno'ed the same or that "all" filters dyno'ed the same?
Al

i'm saying all that I tested dyno'ed pratically the same including some paper. Have tested cone style filters on 1.6 SM's and box type flat filters on 1.8 SM's which barely flow any air (think between HP and FP), but are super repeatable. Some cheap cotton looking filters did poorly when wet. Don't remember all the brands I've tested, but enough that I'll order a KN or GREEN and not worry about it... Same with plug wires and plugs... Sorry :wink:
 
We did alot of dyno testing on the GP rabbit. We tried K-N, Auto-Zone and no filter at all. No difference in any of them. I think if you have a big enough air box and filter it doesn't matter much. I use the Auto-Zone paper one and change every couple of years.
Chuck Mathis
 
Back in my industry days I saw test results from the coal industry that showed that clean paper filters filter better than anything and that you should change all dirty filters regularly. All the oil bath foam filters passed too much grit to meet their equipment replacement budget. At issue is when you get water into the air flow. Paper stops up almost instantly with the introduction of water.

James R.
 
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