CALL911

iTrader: (17)

So in trying to find the most air to my blower, I need to find some info in finding the best flowing air filter (while still running an air filter for its protection).

I currently have a large tubular shaped K&N air filter approximately 14 inches long and maybe 4-5 inches in diameter.

I have seen some designs that are more of a round circular shaped made by different companies as well, but the problem is I have no idea what the CFM or comparison of air movement ability they have between each other.

Is there an air filter website or something that has different flow specs between different air filters? Does anyone have any results with the round circular air filters I am talking about? What about just large air filters in general.

Trying to find a quick solution here, and need info.

Fbodyjunkie06

iTrader: (10)

The biggest one you can possibly fit.

KILLER-LS1

iTrader: (18)

are you talking about the ones shaped like a mushroom? Like the type that lots of Supra's use? If so, your better off sticking with a cone style. The mushroom ones are more for tight clearance. I run an Airaid, they have a synthetic layer on the inside to keep the filter oil from sucking through. they flow the same as a K&N

hitmanws6

iTrader: (20)

I believe K & N has a CFM chart. In theory the filters with an open top would flow better. I also remember reading that a wider shorter filter flows more than a long narrow one

CALL911

iTrader: (17)

All this is good info, however where are you finding the flow readings from K&N? Checking out thier website it seems they have tons of info on the filter itself, but I didn't find any flow readings to really compare where it counts.

Anyone got a link?

93formto98T/A

iTrader: (28)

I've done some research on this. Bottom line is foam flows more than cotton given a similar size filter. If you're looking for a single 1000+hp filter w/o restrictions look at RV or big rig filters. I found a big rig foam filter that wasn't too big and flowed the same cfm as my F2 procharger. The problem is making room in the car for it.

CALL911

iTrader: (17)

Well, foam may flow better, but I am somewhat concerned about it actually filtering as well as a K&N.

Do you guys reccomend the round straight filters over a cone shaped filter?

NASTYTRANSAM

iTrader: (12)

A filter is only as good as the inlet to the blower ! The blower inlet is normally what causes power lose and until you make some kinda change to that the air filter no matter how big or well it flows its gonna be the weak link.

Personally I like the K&N part number RU-3220 its rated for around 900cfm. but the K&N part number RE-0870 also says it rated for around 900cfm

NASTYTRANSAM

iTrader: (12)

I wanna see you test this on your car vs. the normal cone style

K&N RX-4140 - K&N XStream Universal Air Filters

Fbodyjunkie06

iTrader: (10)

I use a big 12" cone K&N with the closed top. I've seen a lot of people using the more square shaped filters lately, especially with big twin screw blowers, and they are probably more sensitive to inlet restrictions.

MaxxMitchell

iTrader: (15)

Did a dyno test with the large spectra code filter you can buy at the parts store. 1140rwhp with an auto with the filter off. 1090rwhp with it on. At 625rwhp and at 800rwhp there was no change in power. Granted this was a turbo car so that may affect why the power did not drop vs the blower cars may see a drop in boost, lowering HP.

JAX04

iTrader: (17)

To add to this, i read a pretty good article that Spectre Filters flow better then K&N

The Beast

iTrader: (16)

Ben, the height of the pleats on the filter makes the biggest difference on filters similar in shape, and can make a smaller filter flow better than a bigger filter. The taller the pleat, the more surface area there is, the less resistance there is. On K&N's site you'll see where they have the amount of oil each filter requires, the more oil it requires, the more surface area there is, the better it will flow. Hope that helps

Old Geezer

iTrader: (3)

with the tech at Spectre..Interesting comment he made.
Said the flow rate on a cone filter can be improved by about 10%, by flowing the air from the outside in..They see less turbulence that way, due to reduced direction changes.
In my case we were discussing the 9831 filter and canister assy they make.

Just like FOX News.. We report, you decide!

CALL911

iTrader: (17)

Nate, the inlet to the blower is the absolute best that can be had. It is metal and it can't be any larger than it is. What I have is a HUGE improvement from the plastic inlet from ATI. I really am just trying to find the best filter.

The RU-3220 is the same (or very close) as what I had originally. This was replaced by Bill with a smaller unit (which is NOT what I wanted). The RE-0870 is definatly smaller, and I find it hard to believe flows the same as the 3220 (but I understand if they "claim" the same CFM. I was looking earlier at a style similar to the RX-4140. I like how the end of the filter is not rubber, but more filter material. The RX-4140 itself is a fairly small filter, so maybe something of the same design except near a foot long might be the best way to go.

I never would have thought of that. Thanks Nick.


I think from what I am gathering that the biggest K&N I can fit will yeild me the best results. It's really going to come down to doing some measuring and trying to see what I can fit in there.

Nitroused383

iTrader: (10)

I remember reading a few old post from guys who build turbo kits they said the AEM dry flow filters ended up being the best flowing filters. http://www.aemintakes.com/dryflow_air_filters.htm

CALL911

iTrader: (17)

If the CFM numbers are accurate between AEM and K&N, then K&N has almost twice the CFM as AEM does with the filters I am looking at.

Aster

iTrader: (9)

I use a Spectre 9738 or 9736 (same filter just different color) which they claim flows 1100 CFM.

How much power are you trying to make? What size pulley combination are you using on the D1?

CALL911

iTrader: (17)

I am maxed out for pulley combo on my D1SC, and really its not about a number, I am just trying to make the most with what I have. The smaller filter that got put on is not as efficient as a larger one.

I have found the largest filter I could. It will be a while before it arrives. My only concern is that it may actually be too large for the area I have to put it in. Time will tell.

I think I have things pretty squared away at this point.

Thanks for everyones input!

Nitroused383

iTrader: (10)

Any update on this? Which filter did you end up with?