Debaffle stock Airbox?

[Jrey]

IDK if this has been answered but, ive been looking around and I've noticed that debaffling the airbox(removing the horn thingy) increases intake sound and better airflow, but this is more of an E36 thing, has anyone ever tried this method?

From what i read up, that horn in the airbox is supposed to smooth out the air flow to the AFM meaning a much better flow to the engine, idk if thats true.

[Nick_S]

I wasn't aware there was much to debaffle on these boxes. They're basically a panel filter inside a box.

[GillesBigCowboy]

I have also wondered about what the horn thingy actually does...

[mbonanni]

Mine makes a horn sound when accelerating, so I kept it in.

[TobyB]

It deflutters your flapper. I left it.

t

[csermonet47]

Flappering your fluttering is important. I would leave it.

[Stanley Rockafella]

I'm baffled as to why one would debaffle the airbox and stop the fluttering

[Zreberlcoe]

What the hell is fluttering?

[jamiholzbach]

According to Performance BMW...

You loose 10ftlbs of torque when you ditch the horn, (I don't know if its true), anyway, keep it.

[slammin.e28]

Some of the best engineers in the world put that there.

Think about that.

[nando]

it may be partially to reduce turbulence but AFMs aren't sensitive to that like MAFs are.

BMW calls the airbox a muffler. I think it's for sound.

[Xat1cZ]

Some of the best engineers in the world put that there.

Think about that.

This ain't no Daewoo brah.

[jlevie]

I tried removing the horn during a dyno session and saw a slight loss in power. In the same session, removing the air box completely resulted in a similar slight loss. The air box isn't the restriction that it might appear to be. In fact it is rather well tuned to the engine's needs.

[nando]

I tried removing the horn during a dyno session and saw a slight loss in power. In the same session, removing the air box completely resulted in a similar slight loss. The air box isn't the restriction that it might appear to be. In fact it is rather well tuned to the engine's needs.

on a stock engine I agree 100%. on a built engine with higher displacement and headwork, it can be a restriction. it makes my engine rather sad after 6000rpm. I still run it during the winter because it's quieter and better sealed, but it makes the car no fun.