camuman

how do you calculate air filter cfm? i swear i want to punch a baby, i have been on kn, aem, and hks sites and they dont say anything about the cfm rating of there filters. ANNOYING. i have been running without one and just want to make sure i dont throw one on that is too small. its a tight space i have to fit it into

Alloy Craft

Cfm of a airfilter is not a set value, an air filter can flow different cfm's,from very little to a whole lot, however as air velocity increases, your drag losses through the fitler increase as the square root of air velocity. To have any idea of an airfilters performance you would really need to look at a graph of cfm vs pressure drop across the filter. The less pressure drop across the filter the better flowing it will be. Most air filter mfg's dont provide this information though.

camuman

Anyone have experience with hks mushroom filters?

DBXFX

This is what I've been wondering for those who have a nice high flowing setup like the fullblown stage 2 but then use those mushroom filters. I have a greddy foam I was thinking of using but it seems inadequate. Watching this thread closely

camuman

i thought about throwing a screen on it, but that only stops big stuff. a real filter will get the grime out of the air. i guess a screen is better then nothing lol, but its so damn tight where the filter would go. LJ, read this lol!

siadam

Alot of people disagree with me on this, but I run a screen with a t bolt, have been for several years now, on several different turbo cars.

However, I don't DD my car, and if I did, I would run a filter. For something I take out on nice day's only, and keep off old dirt/gravel back roads, otherwise they have worked out just fine.

My very first turbo setup on my civic (waaaay back when), was an old junkyward setup from a dsm, a 14b turbo. I ran a makeshift filter and the car always felt slow. Turned out the filter was killing me, it was a k&n, but was to small for my application. Went to a screen and never looked back, and for those un-sure about a 14b turbo, it's SMALL by comparison in what we run on these cars.

DBXFX

I'm thinking since I DD my car that I'll probably make a airbox similar to the comptech icebox in the front passenger corner of the car. Id make it airtight except for the top which would have a large flat filter. This is assuming that there is enough room to make something like this. I was also thinking of somehow running piping or silicone tube to a location with more room, but i dont see that happening with a 4" pipe...

B5254T4

I actually tested last time on the dyno, my 9" AEM didn´t steal a pony at 600+ crank horses.
Had evil thoughts to use a screen instead but happy with these results since it´s much safer.

Edit: Same with a customer car a few days ago, a Volvo C30 with 395whp with and without filter, the shorter model AEM this time.

s2000Junky

Don’t have much to offer up as far as numbers, except I will say foam filters are the way to go for max flow and min filtering ability, if that’s the compromise you want. I run an AFE washable cotton filter in my S and a KN on the Tacoma as a more suitable option for cleaning up the air with good flow. You will likely want to settle on one of those low profile mushroom foam filters for your situation. You can choose to oil it to get the best filtration out of it, or I suppose you could leave it dry for max flow. Anything will be better then the screen you’re running. I wouldn’t risk my investment for 10hp. Crazy bastard

s2konroids

Agree, we tested filters for a customers car. The long and short of it was the foam was the best compromise made by a company called pipercross/ITG. Foam actually filters better when a little dirty with little effect on flow depending on the quality of the filters (some are poor), however most folk over oil foam filters .

IMO and my tuners foam filters are the best compromise in filtration and power.

As said above CFM of an airfilter is not a set value.

I never get anything in my oil when i change it - buts it unlikely to end up in there.