Modifying Stock Airbox on BMW E46?

[HokieZHP]

Has anyone modded the stock airbox with another intake hose to allow more air flow?

[Mtnman]

thats what the bmw performance airbox is....essentially stock bottom with new top.

[Oli77]

You're thinking like making a whole in the bottom section?

[johnrando]

That was my mod, a box switch. Might not be much help to your thread but it could be a nice, clean, OEM way to go.

[HokieZHP]

You're thinking like making a whole in the bottom section?

Yeah something along those lines. Cutting a new hole and running a new intake tube somewhere. Not replacing the section but adding another intake tube into the box.

[Terry]

A guy by the name of Shawn Fogg started doing this to M44 (Z3 and 318 4 cylinders) back in the late 90s. I did it to my 318ti and it's still on. No problems and some added throttle response (and I suppose more aggressive noise when WOT).

[HokieZHP]

johnrando... what part of the box did you switch? And what did you replace it with?

[Mtnman]

Hokie,
Look up the dinan air box for the e46. It is essentially what you want to do. From what i can tell, it just has a tube that goes from the side of the airbox (lower box) to the brake duct. (hence, clean/cool air) Only prob would be if you went through a really deep puddle. But, essentially, i think the dinan box represents what you want to do.

[HokieZHP]

are you referring to this? http://www.dinancars.com/shop/D760-0002-High-Flow-Intake-System.aspx#page=1

Do you think it would be easy enough to DIY? Run another intake tube to the box from the brake duct?

[Mtnman]

Yup. pretty sure ive seen a diy on e46fan. to do this for 30 bucks with parts from lowes.

[HokieZHP]

alright thanks. I'll go poke around over there and see if I can find it.

[johnrando]

johnrando... what part of the box did you switch? And what did you replace it with?

Oops. Must not have been clear. I replaced the whole unit with the performance air intake.