how does the intake filter work

[azn2nr]

ok i think i know the answer but i need some confrirmation.

this morning i buchered my filter in a feble attempt to create a filter. i layed it flat against the maf and bolted it down. this mad it so i could only build about 2 psi of boost.

now, filters are usualy ribed or have ridges/ folded up like a fan. why is this and why does it make the intake work?

secondly would a hepa filter work the same? as in will it make the intake useless. one of thoes fibrous foam ones that go in your home air system.

lastly does anyone know where i can get a flat filter that looks similar to the ones that replace the air cleaner cap on a carb from k&n only that it would fit in a 3 inch pipe.

[BAC5.2]

An accordian style air filter has a HUGE surface area to draw air through. Less air needs to flow through each square inch of filter, the larger the total surface area.

This allows the filter to be very very fine, to do what filters do (filter out particulate matter) and not really restrict air flow.

Just using 3" of stretched out filter is going to flow about as well as shit. I'm surprised the car ran.

To put it in a scenario, I guess you could think of the crumple zones on a car. Basically, more metal to disperse energy across MORE surface.

The larger the surface area of the filter, the less air needs to flow through every square inch, which means HIGHER flow.

A smaller filter (like a mushroom style filter) sacrifices filtering ability for flow and size.

A Hepa filter is not the same thing. It wouldn't last a second to the kind of conditions a filter in a car is subject to.

I still don't understand why you don't consider my advice of moving the charcoal cannister? It's not hard to do, just 4 hoses. There is plenty of room and K&N DEFINATELY makes filters that would fit in that area.

[simonasaur]

If I were you Id just buck up and buy a cone filter and adapt it to your set up. Sounds like your good at fabing stuff so it shouldnt be hard. From what ive gathered the length and diameter of the intake tubimg effect the way air enters the manifold, good luck with that.

I have a vf39 that im going to install, how is yours how long have u had it how much boost are you running did u do a rotated mount are you using fuel upgrades????
Lots of questions
Sam

[BAC5.2]

From what ive gathered the length and diameter of the intake tubimg effect the way air enters the manifold, good luck with that.

True for an N/A. Doesn't make much difference on a turbo application. The plumbing from the filter goes to the turbo, not the manifold.

[azn2nr]

length i think is a factor. my fabricator has a civic that is running an open turbo. when he had an intake on he lost some power.

im looking at the charcoal canister idea but with all of the filters i have looked at on the K&n website there is nothing that would feasibily fit. that and there is no room at all in the car for the charcoal canister anywhere else. i kept the full size battery and got rid of the overflow tank. im using a 16 oz water bottle right now and am looking at ways to use a abs pipe as a new overflow tank.

simonasaur. on stock boost control and 5000 feet eleavation im hittin up to 15psi and a sustained 14 psi at times. mogie style fcd is in the works (opens at 10 psi). regular mounting without twist. pics of the pipes are in the gallery. no fuel upgrades yet. havent flored it yet. the general idea is that i have a case of compressor surge which i will try to remedy with a wrx bov i have that i couldnt find a flage for until today and i wont have it till next wensday. turbo comes on around 2500. spool at that point is verry fast. we have had wet roads the last 2 days and i havent had a dry run yet. wheels keep spinning. fuel cut keeps scaring the shit outta me.

back to the filter. thats what i was thinking what was wrong but the fact remains that i need a filter despratly.

between the maf and the abs unit i can buy 2 inches of space. the thinest knn is 2.6 inches and change. tomorow im gonna call/run down to a few cycle/chopper shops to look for an air cleaner. if you watch american chopper the one they ended up puttin on lenno's bike is the one im looking for.

[BAC5.2]

There are SO many options, come onnnnnn man!

Move the canister to where the airbox was, get a smaller one from a different car, get rid of the winshield washer tank, just rotate the canister on a custom modded bracket. Move the battery, get a smaller battery.

Make a different intake and reposition it. You don't have 2" of space. You have as much space as you need to make. Our engine bays are cramped, but there is PLENTY of room.

A motorcycle filter won't flow enough. Not at all. The bigger the filter the better.

Look at the car stock. You have a snorkus. There is an EASY 4 feet of tubing before the turbo. Remove the snorkus, effectively cut the intake length in half. No change in power (no significant change. Maybe 1 to 2hp tops). The power difference comes from the filter being a restriction. If you listen to my advice, you will actually be Shortening the intake length over what you have AND be flowing more air thanks to the larger filter.

Run open turbo as opposed to having an intake, and there might be a small power loss, ESPICALLY and definately if the filter is not correctly sized to the air volume coming in. A properly designed intake, and there wouldn't be much significant difference. Not enough of a difference to sacrifice turbo life for the extra power.

[azn2nr]

a greddy airinx filter element may work but im afraid that it will behave like the filter i had on this morning.

phill im taking your advice in stride and am trying to think of a way to do it but im just plain stumped.

the cone that i had on there before was about as good as it gets for size and it realy doesnt fit anywhere easily without being cramed in or hitting the hood when i close it.

[IronMonkeyL255]

I was looking at the pics you posted elsewhere.

Try to find something that replaces the elbow directly after the MAF. That would straighten out the intake tract and give you a bit more room.

[G-reg]

I can't recall if there was more than one hole in the fenderwell for the snorkus on the Leg's. If not there was plenty of sheet metal to drill out another and put a big ass filter in the fender. Good luck.

[vrg3]

Jason, I have a suggestion. I'm looking at this picture while I think of it:

http://www.thawa.net/gallery/albums/album18/pipes_2.jpg

Read through it all and decide whether it makes any sense or not.

You have a turbo that doesn't work with stock boost control anyway, so remove the boost control solenoid. Stick a resistor (try maybe a 470-ohm half-watt resistor first) in place of it to make the ECU think it's still there.

You don't necessarily need the auxiliary canister purge system, as long as you occasionally drive off-boost. Get rid of it. Remove the auxiliary purge valve and cap off the fittings it connected to. To be safe, also get a vacuum check valve from an auto parts store and stick it in one of the main purge hoses so vapors can only flow out of the canister. The easiest hose to reach would be the one connected to the top of the throttle body; put the check valve in so it only allows flow into the throttle body and not out of it.

Now you might also try seeing if you can relocate the pressure sensor and pressure exchange solenoid to behind the passenger side strut tower or something. You might have to peel back the corrugated tubing from the wiring harness a little, and extend the 3.5mm vacuum hose.

Now. Out of the three fittings originally needed for the coffee mug, you now only need one. The nipple for boost control isn't needed, and the nipple for auxiliary purge isn't needed. You just need the nipple to supply air to the IAC valve. So -- simplify the coffee mug piece. Make it super short, just barely long enough to include a 3/4" bung for the IAC hose. A couple of inches ought to do.

So now you could connect the MAF sensor straight to the end of your sawed-off coffee mug. Use a short 3" coupler to do this.

It seems to me that if you do all the above you might be able to fit a cone filter right on the end of the MAF sensor, and the filter would sit kind of where the pressure sensor and friends sit now. Or maybe you could put a little elbow on the end and have the filter sit above the intercooler pipe there.

[IronMonkeyL255]

Where did you find the fitting for your mug?

I could only find brass fittings and JB-welded them on. This kept breaking.

I was trying to find some metal ones to have welded on, but had no idea where to look.

[vrg3]

On my version of the resonator delete mod I used a 90-degree 3/4" copper elbow and attached it with solder:

http://www.graphics.cornell.edu/~v/pics ... onator.jpg

If for some reason you can't find one locally, cornerhardware.com carries it:

http://www.cornerhardware.com/productdi ... _id=224466

[azn2nr]

my orignal mug did have jb welded fittings. the one in the pic is a new welded pipe unit.

vrg3, the idea your talking about is similar to the the intake DLC had on his car. im trying to find a pic of it.

as it sits the turbo is using the stock boost control. its just boosting more than stock because of the new spring strength.

[azn2nr]

just as a thought, how do the foam filters work? they seem to be really flat and just put over a cage like the airinx greddy mushroom filters.
something like this http://cgi.ebay.com/ebaymotors/ws/eBayI ... gory=35574 could possibly work but im afraid that it will work the same as the cut up paper filter that i used earlier this week

[THAWA]

Honestly jason, just spend some extra money and do it right with a new resonator delete piece and a different/no elbow.

[azn2nr]

i will. i just need a quick fix until i can have my car down for a few days. and with school its gonna be a while

edit: scrach that . ok i went and took some measurements. from the hoodline to the ic pipe that goes under the intake there is 3 inches. the cone filter is 6 inches deep at the widest and 4 inches at the smallest. between the maf and the abs unit there is 2 inches thick 6 inches wide and about 7-8 inches deep. on the fender wall the larges amount of space where a pipe could pass thorugh is only 2 inches square max. where the charcoal canister is there is only 3 inches square and 6 inches deep. between the abs unit and where the arch for the wheel well there is 1-2 inches max.

what all that is saying is that there is no room to put a propper intake.

so here is what im left with.

a. foam filter. (hoping that this works better in a flat situation than the paper one did)
b. custom air box. (using the area in between the maf and abs unit build a box that bolts to the maf and houses a regular panel filter which i can take out and flip over when one part is used to the max.
c. a really flat mushromm lookin filter a local guy is using that i still need to find more info about.
d. get that super flat k&n that sill might not fit.