M44 OEM Airbox Mod

[BlackBMWs]

I took an hour today to mod my M44 OEM airbox. I wanted to set up for more potential airflow for my DASC install next month while retaining the BMW airbox. I looked at Shawn Fogg's threads on fogging the OEM airbox, but I wasn't so keen on pulling the additional air from below, but he listed an option to draw air from the grill. I saw a thread from Mad-Machine in 2009 and liked the setup in the M42 air draw location. This will also save me from setting up heat barriers for heated air as compared to a cone setup.

Here are the three pieces I used to make a snorkel per Mad-Machine's post: A 4" round to square adapter, a 4" connector and a 3" to 4" male adapter ring. I picked them all up at Lowes for less then $10. The 3" adapter ring is already installed in the airbox in this image.


Here's the stock intake port on the side and the new intake port in the front of the airbox. After taking out the internal framing/sound deadening in the airbox, I used a hole saw to cut a 3" hole, then opened it up a little with a rotary rasp on my cordless drill to allow the adapter to screw in-place.


Here's the airbox in place with the snorkel and connector in place. The snorkel fits inbetween the driver's side headlight and the radiator, Similar to the M42 setup. I took some plastic off the new snorkel to fit more snugly and straighter in place.


Here's the finished product in place.


The airbox installs and deinstalls as normal with just the addition of aligning the new snorkel. I left the original snorkel in-place, so I'm getting airflow from both inboard sides of the headlights. I do plan to swap out the K&N and go back to a paper filter.

Accelleration seems zippier over 3500 rpm. (Sean... See zippy reference... ). Not really any louder, I'll listen harder tomorrow. I'll zip around a bit more tomorrow to see if I notice more of a difference.

Thanks to Shawn Fogg and Mad-Machine for their ideas and configuration.

[markslc1]

What did you do to the stock snorkel? Block it off somehow?

[BlackBMWs]

For the moment, I left it in place. I suspect I'll need to remove it once the DASC goes in. I have the 3" piece I removed which I can epoxy or JB weld in place over the OEM airbox intake hole. If it can fit without impacting the DASC, I'm inclined to leave both snorkels in place.

Between the 3" new snorkel and the stock snorkel, I suspect it's pulling plenty of outside air.

(updated the main text with these notes)

[BlackBMWs]

Out and about today. It does seem more responsive over 3500 RPM in general. No difference below 3500 it seems. Driving feel, no dyno.

I may pick up a 3" cap to close off the new path as a comparison to see if I'm just imagining better response next time I'm at Lowes or Home Depot.

[Bokey]

How does one remove the original snorkel piece from the airbox?

I had my airbox off the other day as I was changing the oil filter gasket and I was looking at my airbox and tugged a bit and stared at the snorkel and I couldn't for the life of me figure out how to detach it from the airbox.

[BlackBMWs]

Originally Posted by Bokey

How does one remove the original snorkel piece from the airbox?

I had my airbox off the other day as I was changing the oil filter gasket and I was looking at my airbox and tugged a bit and stared at the snorkel and I couldn't for the life of me figure out how to detach it from the airbox.

There's a tab on the bottom of my snorkel that you have to lift to release the snorlel.

[Bokey]

Originally Posted by BlackBMWs

There's a tab on the bottom of my snorkel that you have to lift to release the snorlel.

Guess I'll have to look harder next time then, the only remarkable thing I remember is the tabby latchy thing between the snorkel and the airbox. But other that it looked like it was held together by magic.