[Jeremias]

Has anyone modified their stock intake box to gain more airflow from cutting or drilling holes in the bottom of the box? Before you start commenting about all the hot air, refer to almost everyone that runs DCI’s. It seems to me that over 1/3 of the stock air filter isn’t even utilized because of the “hump” blocking the left side of the filter. I suppose that cutting out the bottom of the box would provide almost the same amount of available airflow by increasing filter area as installing DCI’s as well as leaving a stock looking box(for emissions testing).

[vladskies]

Haven't done something like this, so I have no comment there

But if you're going to do this in order for more airflow, and passing emissions then save the hassle and get BMS DCI's. They are made for that

Quoted off their website...

"50 State Legal. CARB Approved Under Executive Order (EO) No. D-744-2 for all 2007-2012 BMW models equipped with the N54 3.0L twin-turbocharged 6-cylinder engine."

https://burgertuning.com/products/bm...ke-for-n54-bmw

[Bimmer_Engineer]

I'd like to seem some kind of combination of the burrito intake with this swiss cheese airbox idea...

[BSM n54iS]

Originally Posted by Bimmer_Engineer

I'd like to seem some kind of combination of the burrito intake with this swiss cheese airbox idea...

You'd want more of a burger combo goin on with swiss cheese I thought

[Bimmer_Bro]

Originally Posted by Jeremias

Has anyone modified their stock intake box to gain more airflow from cutting or drilling holes in the bottom of the box? Before you start commenting about all the hot air, refer to almost everyone that runs DCI’s. It seems to me that over 1/3 of the stock air filter isn’t even utilized because of the “hump” blocking the left side of the filter. I suppose that cutting out the bottom of the box would provide almost the same amount of available airflow by increasing filter area as installing DCI’s as well as leaving a stock looking box(for emissions testing).

This theory has been explored a lot already. A couple issues with it.
Yes you will be sucking in more hot air VS stock. It will also make your snorkel a little useless. The engine will suck in air from the path of lease resistance. So there for you are sucking in engine air vs exterior air. ( You could add scoops to help force air through to combat this issue).

Another reason why it doesn't really do much is the main restriction point is the space where the air crosses over after its gone through the filter. That space is quite small and making more air on the unfiltered side is not going to help the amount of air that can pass over and down to the inlet tubes.

Google the MR5 intake. That is the best solution keeping the system closed but adding another tube to the filtered size of the box, providing more flow of cold air. The Stett CAI has this design as well.

Honestly cutting up your box will do nothing. Some users have had good luck using a Z4 lid as they are taller...but hard to find and not worth the cost.

I have ran both DCI and stock box. I prefer the feel of the stock box.
I shaved the fins out of the lid of my box but left the filter support brace in. Probably adds nothing but at lease the lid is smoother now. That paired with a drop in filter.

[Jeremias]

I agree with you. Hopefully the cooler air will get suctioned first since it is closer to the intake. Just trying to squeeze every dime I can. I also shaved the fins.

Originally Posted by Bimmer_Bro

This theory has been explored a lot already. A couple issues with it.
Yes you will be sucking in more hot air VS stock. It will also make your snorkel a little useless. The engine will suck in air from the path of lease resistance. So there for you are sucking in engine air vs exterior air. ( You could add scoops to help force air through to combat this issue).

Another reason why it doesn't really do much is the main restriction point is the space where the air crosses over after its gone through the filter. That space is quite small and making more air on the unfiltered side is not going to help the amount of air that can pass over and down to the inlet tubes.

Google the MR5 intake. That is the best solution keeping the system closed but adding another tube to the filtered size of the box, providing more flow of cold air. The Stett CAI has this design as well.

Honestly cutting up your box will do nothing. Some users have had good luck using a Z4 lid as they are taller...but hard to find and not worth the cost.

I have ran both DCI and stock box. I prefer the feel of the stock box.
I shaved the fins out of the lid of my box but left the filter support brace in. Probably adds nothing but at lease the lid is smoother now. That paired with a drop in filter.

[Bimmer_Bro]

Originally Posted by Jeremias

I agree with you. Hopefully the cooler air will get suctioned first since it is closer to the intake. Just trying to squeeze every dime I can. I also shaved the fins.

Fair enough, but drilling holes there is not going to provide any gains. Just warm air right off the engine manifold. Keep the system closed so colder air can be drawn from the exterior, or do the MR5 snorkel....that seems to provide better gains than a dci.

[BSM n54iS]

Guys, just go with a GruppeM intake

[TiAgAu]

Hope you don't mind me using your pic.

One thing i noticed with oem filter it's alot thicker and sits lower in the box. As you can see it blocks some of the intake flow. It's minor but with stock box it all helps. K&N filter or similar doesn't block off the flow there.