Air intake filter - yes or no?

[TexasTezla]

I installed the leaf guard 18 months ago. Negligible airflow difference on AC. Instead of 3 I might need 4, or 6 instead of 5 etc. No biggie. The good news is that no leaves, bugs or crap has gotten deep down there. Worth the $18 I paid!

 

[MLXXXp]

After reading this thread and considering all the stuff that's gotten under the hoods of my previous cars, I though adding an air intake screen might be a good idea and decided to try a D.I.Y approach. I have a 2021 M3 (with heat pump).

I figured aluminum window screen would be a good material to use. It has a fine mesh and the opening to blockage ratio is high. After looking things over, I decided that putting it on the cover panel would be easier than fitting and anchoring a piece to the intake port.

I cut the screen to the proper shape with edges that would fold down over the sides of the underside of the vent. I put a strip of 3M 9475LE double sided tape on the sides of the vent and bent the edges of the screen onto them. I then put aluminum foil tape over the sides. I put a double layer of foam "truck cap" tape where there was a gap in the intake port foam. I hope it all holds up over time.

Also, while I had the cover panel off, I put dots cut from blue electrical tape on the outside of the panel marking the positions of the clips, to make it easier to know where to pull or push to remove or reinstall it.

 

[TexasTezla]

Nice looking job there!

 

[Rattletrap]

I used the same version except I drilled the holes to 9/32 or .281. It allowed alot more flow and I was just trying to stop larger leaves and pineneedles from going in. Easy on a drill press.View attachment 684572

Holy crap, is that the Abstract Ocean version? How long did this take to widen each hole with hand tools?

 

[MaxwellN22]

Get a high flow to increase horsepower.

 

[wws]

Get a high flow to increase horsepower.

Don't laugh. K&N sells cabin filters these days. COVID masks too.

 

[Rmchrger]

Holy crap, is that the Abstract Ocean version? How long did this take to widen each hole with hand tools?

Its one from amazon. Probably the same thing. It would definitely take longer drilling by hand. I used a drill press, only took about 15 minutes. But seemed like it took 45 min...lol. Funny part, I did it twice, first drilled it to 1/4" .250 and still had to much restriction (IMO) so I drilled it again to .281 and I like it better. And hey, doing it twice I think I got 10 more horsepower instead of 5...but MLXXXp's, his is silver so he got 15 horsepower...
MLXXXp, great job, I like the different approach.

 

[oalvarez]

Is anyone’s late 2021 year M3P missing the shroud/surround that would be directly attached to the air intake under the plastic cover in the trunk?

Mine doesn’t…as in there‘s only the intake itself, nothing to be removed from it.

Thanks in advance,

 

[ss71]

After reading this thread and considering all the stuff that's gotten under the hoods of my previous cars, I though adding an air intake screen might be a good idea and decided to try a D.I.Y approach. I have a 2021 M3 (with heat pump).

I figured aluminum window screen would be a good material to use. It has a fine mesh and the opening to blockage ratio is high. After looking things over, I decided that putting it on the cover panel would be easier than fitting and anchoring a piece to the intake port.

I cut the screen to the proper shape with edges that would fold down over the sides of the underside of the vent. I put a strip of 3M 9475LE double sided tape on the sides of the vent and bent the edges of the screen onto them. I then put aluminum foil tape over the sides. I put a double layer of foam "truck cap" tape where there was a gap in the intake port foam. I hope it all holds up over time.

Also, while I had the cover panel off, I put dots cut from blue electrical tape on the outside of the panel marking the positions of the clips, to make it easier to know where to pull or push to remove or reinstall it.

View attachment 691112View attachment 691113View attachment 691114

I found this thread today as my vent cover from Abstract Ocean arrived. I decided to try the window screen method as well. Will see how it holds up and can use/modify the AO cover if needed.

 

[Flybyglass]

I did this with gutter screen from Home depot for $4 and weather stripping from Amazon.

 

[moriwaky]

hi! I have problems reataching the cover for the intake. There are like 8 white plastic press screws arround the cover. but I only can fell that the side screws are press, the midle of the cover is flexing too much with the under cover and they don´t go all the way in. Any tip? the cover seems fix anyway only with 4 point well attach

 

[Flybyglass]

hi! I have problems reataching the cover for the intake. There are like 8 white plastic press screws arround the cover. but I only can fell that the side screws are press, the midle of the cover is flexing too much with the under cover and they don´t go all the way in. Any tip? the cover seems fix anyway only with 4 point well attach

Thats just how it is press down best you can.

 

[moriwaky]

Thats just how it is press down best you can.

thanks mate! I try my best and only 4 go in. Maybe trying my best minus all my fear broking somenthing, will improve the results!

 

[wws]

thanks mate! I try my best and only 4 go in. Maybe trying my best minus all my fear broking somenthing, will improve the results!

Put a bit of tape on the other side of each fastener. Then you'll know where to press.

 

[jsmay311]

Out of curiosity, I removed my cabin air filters and installed just an intake filter. I can’t tell if there’s an increase in airflow or not… curious how dirty it will get and how fast.

Will update later

Any updates?

 

[medphys3]

Out of curiosity, I removed my cabin air filters and installed just an intake filter. I can’t tell if there’s an increase in airflow or not… curious how dirty it will get and how fast.

Will update later

Update- I didn't notice any real difference, but found that my "outside" air filter was kind of getting pulled down in a bit, and I was worried that it would get wet in the rain and snow. I ultimately put the OEM's back in.

 

[insaneoctane]

After reading this thread and considering all the stuff that's gotten under the hoods of my previous cars, I though adding an air intake screen might be a good idea and decided to try a D.I.Y approach. I have a 2021 M3 (with heat pump).

I figured aluminum window screen would be a good material to use. It has a fine mesh and the opening to blockage ratio is high. After looking things over, I decided that putting it on the cover panel would be easier than fitting and anchoring a piece to the intake port.

I cut the screen to the proper shape with edges that would fold down over the sides of the underside of the vent. I put a strip of 3M 9475LE double sided tape on the sides of the vent and bent the edges of the screen onto them. I then put aluminum foil tape over the sides. I put a double layer of foam "truck cap" tape where there was a gap in the intake port foam. I hope it all holds up over time.

Also, while I had the cover panel off, I put dots cut from blue electrical tape on the outside of the panel marking the positions of the clips, to make it easier to know where to pull or push to remove or reinstall it.

View attachment 691112View attachment 691113View attachment 691114

@MLXXXp or @ss71 ....either of you have an update on how the tape is holding up securing the aluminum screen?

 

[Kandiru]

Get a high flow to increase horsepower.

The short air intake with K&N filter behind the foglight, I remember a guy who hydrolocked his engine driving through rain after doing it on his Golf.

IMHO the "OMG The Odor..." threads here are due to leaves and insects falling through and just rotting over the air filter.

 

[Rothgarr]

The short air intake with K&N filter behind the foglight, I remember a guy who hydrolocked his engine driving through rain after doing it on his Golf.

IMHO the "OMG The Odor..." threads here are due to leaves and insects falling through and just rotting over the air filter.

I think it's some sort of mold. When I cleaned my coils and replaced the filters after really bad smell there was maybe one small fragment of leaf (like a square centimeter), and one bug. Not enough for a smell.

The filters were dirty, though. I think the dust/dirt get wet and doesn't get a chance to dry and gets stinky.

 

[ss71]

@MLXXXp or @ss71 ....either of you have an update on how the tape is holding up securing the aluminum screen?

I hadn’t looked at it in months so I did today after giving the car a wash. I’d say the tape and screen are holding up… not super well. The tape I used, aluminum duct sealing tape, is not adhering well anymore. Probably should investigate something different. The foam around the intake does keep things pretty well in place though. It was also clear to see that water can easily get into the air intake and the screen had kept some debris out.