Modifing stock airbox to fit M30 AFM

[rs4pro3]

rwh11385 asked me to post about this. I was going to do the m30 AFM swap but didn't want to use a cone filter. So I modifed a stock airbox to hold the Big six AFM.
To start remove the 4 philips screws holding the Cone filter adapter onto the M30 AFM)keep the gasket handy)
Next I took a spair m20 Airbox I had(plastic latter style) and disasembled it and pulled off the Air horn
I lined the m30 afm up and was able to use some short 10mm bolts. The bottom two holes and bottom two holes on the M30 AFM lined up perfectly so I bolted it into place.
The top 2 bolts on the m30 afm were higher then on the m20 airbox. So I took an exacto knife and marked the center of each hole on the airbox. I then removed the m30 air flow meter, and used an 7mm drill bit drilled out the two holes I just marker.
I know bolted the m30 AFM on but you'll notice the hole for on the m20 box extends down into the m30 afm opening. What I did was removed the AFM and used a hack saw to cut the opening larger, I cut untill I got threw the small metal plate that goes aroung the opening.
Then I just bolted the m30 afm and gasket into place and now had a modifed m20 airbox that fit the m30 AFM perfectly. You probally won't be able to use the Air horn now. But you'll still have a stock appearing engine bay. Sorry I don't have any pics but I sold the m30 afm and airbox a while back. I think this setup works a lot better then the cone filter(unless you properly shield the filter)
Hope this helps any one who is considering the m30 afm upgrade.

[nando]

I considered this as a solution to mounting mine, but I didn't want to destroy my airbox. I think the factory airbox probably flows as well as most cone filters anyway..

[rs4pro3]

I'd picked up a airbox for $5 at the junkyard so I didn't care.

[rwh11385]

I'd picked up a airbox for $5 at the junkyard so I didn't care.

I think I know someone who will give me his for free, if he still has it that is.

That, or I properly shield Nando's generic cone filter.......

[Bryson]

if i knew where mine was it'd be yours too many spare parts, spare m20 parts, useless to me.. except the starter, but I have no spare :?

the m30 afm and stock box would be the way to go i think, plus it's cheaper than a cone filter, if you didn't already have one, i mean. and it looks better :)

[rwh11385]

Bryson, hopefully I'll be able to mod a box before using an open-element filter....I might get addicted to the sound.

It would be a much cleaner, and much more sleeper mod to have the stock box there.

[Bryson]

if you like the sound of the cone, you can always build an ABS plastic airbox that looks relatively factory (heat and bend instead of cut and bolt together)
It's what I did with my 24v motor

[Sean]

If you drill holes in the airbox, along with an M30 afm - shit, that would sound sooo badass.

Believe it or not, I drilled holes in an extra airbox on the 87 325 - and at full throttle it has a VERY noticeable growl - it sounds awesome!

Awesome idea - I'll definately be doing this down the road.

[rwh11385]

if you like the sound of the cone, you can always build an ABS plastic airbox that looks relatively factory (heat and bend instead of cut and bolt together)
It's what I did with my 24v motor

pic? :P

thanks

[Bryson]

You should know me well enough that I don't document my mods

Things I've done this month:
m50
alu flywheel/m3 clutch
foglights
splitter for is lip
m-tech 1 steering wheel
smoked headlights
I know I'm missing something else, but I'll get you a picture of the box as soon as I can find my camera. It's 2/3 finished

[Bryson]

Robert, I got you covered. Of course, this is lacking the top piece which is yet to be made

[e30Matt]

Ever thought about putting some weatherstripping on top to seal it, at least until the top piece is made? That should drop temps all the bit more.

[rwh11385]

Hey, that shit is hot.

Where'd you find ABS like that? Home Depot?
And how'd you bend it best, heat gun or what?
I'd really love to construct something of that quality.....

p.s. sweet new sig. E36 poser :P

[Bryson]

It's 3/16" ABS plastic and I bought it at a local plastics shop. It's about $20 for a 4' x 4' sheet
I bent it using a box as a straight edge (table works fine) and a long time spent with the heat gun. After it's heated up to the correct temp, it will bend itself, don't force it. I made the template out of a piece of cardboard also, I'll do the same for the top piece.

I did notice that the filter still felt warm after driving so plenty of air is coming through the top (1" gap all around) but I should make the top really soon, so no big deal. I'm also planning on using pieces of factory trunk seal for the intake just because it's factory :)