I'm making around 780 whp with the AEM 6.5" long filter with no problems at all. If I'm losing any power from the filter, I would imagine it isn't much.

 

Those are not good. I have personally seen one come apart and suck into a turbo. (i didnt actually see it suck it in but was there when the turbo came apart). They deteorate alot faster than others so i think thats the case. I would use the largest you can that will fit in your area you have.

 

I have nice filter story for you.

Many, many, many years ago we had car competing in the FWD street class. Around 800bhp with an ITG filter rated to those numbers.
After the first run we checked the log and saw that 10psi of boost were missing, our tuner raised it and off we went. Back again and checking the log, still 10psi missing...
Hmmm... Difference between the dyno day in the Superflow and here? Ah! The filter! We removed it and did the first burn out, damn, you could hear a new monster.
After a the 60 foot mark we heard a big boom, the head and block went different ways and blew the radiator into pieces. When we got the car back and checked the log we found a nice 50psi run and around 1200bhp before it blew.

When we got home we called the ITG dealer and asked if he had a bigger filter?
-Nooo, the 500bhp one is the biggest, we wrote 800 on that one before but that´s totally wrong, typo, haha...
Very funny...

Since that day we always use the same parts in the dyno as on the road.

 

that is quite a filter story! my problem is i cant fit a big filter, so im worried im gonna stuff one in there that just isnt big nough. im gonna pick up a aem dry filter 4" inlet 6" long like spoolin runs, that will flow enough, but fitting it is gonna be a biatch,.

 

uopdate, i ordered 3 different aem dry filters from summit. hoping to get the biggest one to fit, then return the others. ill post pics when i get this done.

 

Didnt the mase kits have problems with the AEM filters melting? Something to be mindful of...

 

Thats my problem. I could possibly run a tube off my turbo to a filter, b/c a turbo won't fit on the end b/c of hood clearance.

 

I run a short 4" bend welded to the turbo and no melting problems yet. My buddy got one on the turbo very close to the manifold on a M3 turbo and no melting either, maybe an old problem? Fixed?

 

Bump for this, I just personally went to clean that mushroom HKS filter and it fell appart with just water applied to it in the sink in about 5 seconds. The entire thing nearly melted in my hands, the foam was absolutely destroyed. Happy I didn't run something like that on my motor!

EEEEK

To the OP:

The manner to measure a filter is CFM vs PSI loss. Essentially you flow a given ammount of air through the filter and then you calculate pressure on both sides and note the difference. It'd be smart to do a few different CFM numbers to provide some accurate readings for different applications.

It would be pretty easy to design a test box to do this. If anyone wishes to spend a few hundred bucks to fund the project I'll happyily design the acrylic box to test filters in. It'll consist of a acrylic box, two pressure sensors, a internal wall to hold the filter and a fan to draw air through the device, hopefully with a low/med/hi setting switch.

Then we could have some REAL data.


As far as filters go, I prefer FOAM/OIL filters, they do incredibly well with a lot of dirt in the air in terms of keeping your motor safe and they flow quite well even when fairly clogged. Hence why it's all that's used in motocross bikes. General rule of thumb, bigger is better when it comes to filters, the bigger the filter, the finer the foam can be. A small filter that flows well, also flows dirt in your motor, I stay away from K&N. I've done my own tests to see how much dirt comes through em, eeek.

-Greg