E90Post
 


Mtrack
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N57 / M57 Turbo Diesel Discussions - 335d > Quick & Dirty Engine Air Filter "Mod"



Reply
 
Thread Tools Search this Thread
      01-29-2013, 08:01 PM   #1
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quick & Dirty Engine Air Filter "Mod"

Evening, Ladies & Gents,

I've been considering removing the foam "pre-filter" piece from my engine air filter for some time. It has always been my opinion that it is there more for acoustic dampening than for actual filtration. My only concern has been that fully removing the foam piece could somehow affect the seal of the filter against the box and therefore increase the pressure at which the spring loaded secondary intake in the box would be activated.

I'll start by saying that I am over-complicating this and you could probably just rip off the foam piece without any adverse effects, however, this is how I decided to proceed...
  • I installed my new filter and left it in the car for a week so that the box would make a clear indentation on the foam.
  • I then pulled the foam almost entirely off of the paper element, leaving the area of foam which sits over the secondary springloaded section and the indentation intact (glued)
  • Next I cut around the indentation leaving about 1 cm between the indentation and the cut.
  • The final result was a filter which has a naked paper filter on the primary section of the box but retains the pre-foam filter on the seconday section of the box (really just for the sake of the "seal").
  • I then reinstalled the filter and started the engine.

Ze box...

Ze filter...

Ze modification...


Results? Believe it or not, there is a very mildly increased intake noise with a small bit of added grumble. It is (to me) only noticeable when outside the car or with the windows down, but I asked my wife to tell me if she noticed anything different and she stated that the car sounded "angrier". Were you to emulate the above...if you rev your car while parked before and after, I think you'll notice a slight difference as well.

I would imagine that the difference is similar to that of adding a K&N filter, but without the filtration concerns that come with the K&N (for some). For a free 90-second modification, I'll take it.
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )

Last edited by FormerRotor; 01-30-2013 at 01:49 PM.
FormerRotor is offline  
0
Reply With Quote
      01-29-2013, 08:39 PM   #2
335dFan
Jumping Jack Flash
 
335dFan's Avatar
 
Drives: 2011 335d
Join Date: Nov 2012
Location: Maryland (near Annapolis)

Posts: 919
iTrader: (0)

Garage List
I really enjoy reading all these posts demonstrating our passionate love affairs with our cars. Only we would get it I guess.
__________________
Mods-Etc: Quaife LSD w/VAC finned diff cover, M3 Rear SF Bushings, M3 sways & OEM Susp Front/Rear Cmpnt Kits ('cept strut brace), GC Caster/Camber Plates, AC Schnitzer M3 Sport Springs, JRZ RS1 dampers, JBD 100%, Goodrich SS brake lines, non-stggrd APEX ARC-8 18" wheels with Michelin PSS tires (winter OEM 17" wheels and Blizzak LM-25).
335dFan is online now   United_States
0
Reply With Quote
      01-29-2013, 08:58 PM   #3
Julesandtrish
Private First Class
 
Julesandtrish's Avatar
 
Drives: 335d
Join Date: Jan 2010
Location: North Carolina

Posts: 187
iTrader: (1)

Garage List
2010 BMW 335D  [5.00]
FormerRotor, can you post a pick for clarification? I have a picture in my head of what you describe, but I just want to make sure. Thanks in advance.
__________________
Enjoy what you drive.
Julesandtrish is offline  
0
Reply With Quote
      01-29-2013, 09:02 PM   #4
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

^Yeah, I tight about it the second that I dropped the hood. I'll take a pic in the morning and add it to the original post.
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
      01-29-2013, 09:03 PM   #5
Julesandtrish
Private First Class
 
Julesandtrish's Avatar
 
Drives: 335d
Join Date: Jan 2010
Location: North Carolina

Posts: 187
iTrader: (1)

Garage List
2010 BMW 335D  [5.00]
Cool. Thank you sir.
__________________
Enjoy what you drive.
Julesandtrish is offline  
0
Reply With Quote
      01-29-2013, 09:09 PM   #6
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by 335dFan View Post
I really enjoy reading all these posts demonstrating our passionate love affairs with our cars. Only we would get it I guess.
Yes, I suppose we are a bit fanatical, aren't we? I've really enjoyed going back and reading the old posts on this forum from the diesel pioneers (TDI and the likes). I was one of the first in my area to take delivery of a rx8, so I often forget that a lot of guys have been at it with the diesel for 3-4years already.
Quote:
Originally Posted by Julesandtrish View Post
Cool. Thank you sir.
My pleasure, but you might not want to thank me until I don't forget to do it.
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )

Last edited by FormerRotor; 01-29-2013 at 09:14 PM.
FormerRotor is offline  
0
Reply With Quote
      01-29-2013, 09:51 PM   #7
Julesandtrish
Private First Class
 
Julesandtrish's Avatar
 
Drives: 335d
Join Date: Jan 2010
Location: North Carolina

Posts: 187
iTrader: (1)

Garage List
2010 BMW 335D  [5.00]
FormerRotor, can you elaborate on how the secondary spring loaded section of the air filter box works? I see it, but don't understand how it works. Does it help blow off water/fluids that get in there?
__________________
Enjoy what you drive.
Julesandtrish is offline  
0
Reply With Quote
      01-29-2013, 11:12 PM   #8
Got_Diesel
Private First Class
 
Drives: 335d
Join Date: Dec 2012
Location: United States

Posts: 126
iTrader: (0)

I pulled off the old foam paper on my air filter once it got dirty and it worked just fine.

From what i know, that foam paper is only used for snow.
Got_Diesel is offline  
0
Reply With Quote
      01-30-2013, 01:54 PM   #9
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by Julesandtrish View Post
FormerRotor, can you elaborate on how the secondary spring loaded section of the air filter box works? I see it, but don't understand how it works. Does it help blow off water/fluids that get in there?
Edited OP with pics for your reference J&T.

I'm obviously not a BMW design engineer, but it seems to me that the spring was likely selected to be compressed at a certain negative pressure to allow air into the box from the engine compartment. This would likely be useful if the intake were clogged so that the engine is not choked out.
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )

Last edited by FormerRotor; 01-30-2013 at 02:13 PM.
FormerRotor is offline  
0
Reply With Quote
      01-30-2013, 03:36 PM   #10
Got_Diesel
Private First Class
 
Drives: 335d
Join Date: Dec 2012
Location: United States

Posts: 126
iTrader: (0)

Quote:
Originally Posted by FormerRotor View Post
I'm obviously not a BMW design engineer, but it seems to me that the spring was likely selected to be compressed at a certain negative pressure to allow air into the box from the engine compartment. This would likely be useful if the intake were clogged so that the engine is not choked out.
Correct. If the intake gets clogged with snow, the other warm air intake opens and lets air in. I believe VW does this too.
Got_Diesel is offline  
0
Reply With Quote
      01-30-2013, 04:59 PM   #11
sohcpunk
Second Lieutenant
 
sohcpunk's Avatar
 
Drives: 2011 335d
Join Date: Feb 2012
Location: Socal

Posts: 283
iTrader: (3)

Garage List
2011 335d  [0.00]
I wonder how the dealership will take this when they change out your filter to find it's been "modified". Wouldn't they note it down and if something were to happen to the engine in the future deny warranty?
sohcpunk is offline   United_States
0
Reply With Quote
      01-30-2013, 06:20 PM   #12
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by Got_Diesel View Post
Correct. If the intake gets clogged with snow, the other warm air intake opens and lets air in. I believe VW does this too.
Thanks for the confirmation, gd! At first, I wasn't sure what you meant by it "being for snow". I thought you were alluding to the foam and got a bit confused

Quote:
Originally Posted by sohcpunk View Post
I wonder how the dealership will take this when they change out your filter to find it's been "modified". Wouldn't they note it down and if something were to happen to the engine in the future deny warranty?
I have a spare one in the garage that I can always toss in. If you are in- warranty, then they would have to prove that this caused the failure (highly unlikely). If out of warranty, then it may cost you some leverage when looking for concessions.

You are not removing any filtration capability by removing the foam and the actual filtration media is the pleated paper filter behind the foam. Te only thing you may be doing is causing the filter to load more quickly as you are reducing the surface area (but the foam is porous enough that it is really only catching the big bits). If they were smart enough, they would likely feed you some bologna about how the foam disrupts the cavitation of airflow in order to more evenly disperse the air over the filter media and allow more regular flow over the MAF (but this would be bologna), especially considering that they have many other vehicles with newly identical box design and only a paper filter (no foam).
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
      01-31-2013, 10:11 AM   #13
Puerto Rican 335d
Colonel
 
Puerto Rican 335d's Avatar
 
Drives: Montego Blue 335d
Join Date: Jun 2011
Location: Puerto Rico

Posts: 2,030
iTrader: (0)

Rotor I hv not forgotten you I will try to send pics today ok Im under construction at my home
__________________
RENNtech Flash/WAGNER IC
VMR710 19"/Execuhitch Hitch/Koni FSD
Soft Ride Bike Rack
Amsoil Cetane Boost Diesel Fuel Additive
Amsoil Diesel Fuel Additive Concentrate
Puerto Rican 335d is offline   Puerto Rico
0
Reply With Quote
      01-31-2013, 11:15 AM   #14
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by Puerto Rican 335d View Post
Rotor I hv not forgotten you I will try to send pics today ok Im under construction at my home
Haha. No worries, PR. This is all of our "second lives", the primary has to take priority. Talk soon! What kind of work are you doing?
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
      01-31-2013, 12:04 PM   #15
Puerto Rican 335d
Colonel
 
Puerto Rican 335d's Avatar
 
Drives: Montego Blue 335d
Join Date: Jun 2011
Location: Puerto Rico

Posts: 2,030
iTrader: (0)

Expanding closet to garage to add either a Diesel or Gas(Natural) Generator and hang my bikes there!!
__________________
RENNtech Flash/WAGNER IC
VMR710 19"/Execuhitch Hitch/Koni FSD
Soft Ride Bike Rack
Amsoil Cetane Boost Diesel Fuel Additive
Amsoil Diesel Fuel Additive Concentrate
Puerto Rican 335d is offline   Puerto Rico
0
Reply With Quote
      01-31-2013, 02:24 PM   #16
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by Puerto Rican 335d View Post
Expanding closet to garage to add either a Diesel or Gas(Natural) Generator and hang my bikes there!!
Nice! I love me some garage work
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
      02-01-2013, 05:59 AM   #17
Puerto Rican 335d
Colonel
 
Puerto Rican 335d's Avatar
 
Drives: Montego Blue 335d
Join Date: Jun 2011
Location: Puerto Rico

Posts: 2,030
iTrader: (0)

rry amigo having issues with neighbors about the garage issues i am within the required parameters of construction and they're stating i have it wont , would you believe that they came at 7:30 pm to complain needless to say I tod them I was NOT coming down from my 2nd floor house to see at that LATE any inuendos i am within the property guidelines, Ive contacted the Complex Administrator and an Filed ngineer friend of mines and both state I doing everything correctly, People can be such wads, what eats me is that I know I am doing things correctly and people are trying to falk w me. I'll keep u posted Im sorry I hvnt sent you the pics but will try today ok
__________________
RENNtech Flash/WAGNER IC
VMR710 19"/Execuhitch Hitch/Koni FSD
Soft Ride Bike Rack
Amsoil Cetane Boost Diesel Fuel Additive
Amsoil Diesel Fuel Additive Concentrate
Puerto Rican 335d is offline   Puerto Rico
0
Reply With Quote
      02-01-2013, 10:25 AM   #18
GSXR
Registered
 
Drives: K6GSXR750
Join Date: Jan 2013
Location: Long Beach CA USA

Posts: 3
iTrader: (0)

Just out of curiosity, does anyone have the k&n drop in filter? I'm a new member lurking (hopeful future owner) and am surprised at the aftermarket availability (US) of this engine, I'm used to the cold air intakes and the only drop in k&n filters Ive used where on my bike but I have never owned a forced induction vehicle so does anyone know if it would be similar results to remove this foam piece as opposed to getting the k&n drop in? Either way, it is a pretty good free mod
GSXR is offline  
0
Reply With Quote
      02-01-2013, 07:24 PM   #19
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by GSXR View Post
Just out of curiosity, does anyone have the k&n drop in filter? I'm a new member lurking (hopeful future owner) and am surprised at the aftermarket availability (US) of this engine, I'm used to the cold air intakes and the only drop in k&n filters Ive used where on my bike but I have never owned a forced induction vehicle so does anyone know if it would be similar results to remove this foam piece as opposed to getting the k&n drop in? Either way, it is a pretty good free mod
Candidly, I don't think either are really going to give you any gains that would be larger than what could be considered a testing error on a dyno (or even close there-to). Some folks do have k&n, but others believe that the cost of possible reduced particulate filtration and possible oil issues are not worth the possible benefits. Many here in the diesel section cite the Spicer report.

What's keeping you from buying the diesel? we'd welcome you to the dark side
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
      02-01-2013, 07:59 PM   #20
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by Puerto Rican 335d View Post
rry amigo having issues with neighbors about the garage issues i am within the required parameters of construction and they're stating i have it wont , would you believe that they came at 7:30 pm to complain needless to say I tod them I was NOT coming down from my 2nd floor house to see at that LATE any inuendos i am within the property guidelines, Ive contacted the Complex Administrator and an Filed ngineer friend of mines and both state I doing everything correctly, People can be such wads, what eats me is that I know I am doing things correctly and people are trying to falk w me. I'll keep u posted Im sorry I hvnt sent you the pics but will try today ok
Yah, that's one of the big pains of construction. Doing it right is fairly easy. Repeatedly having to prove that your work is being done right is a pain. If you don't have a good relationship with them anyway, just tell them to call the complex administrator if they have any concerns,
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
      02-01-2013, 10:06 PM   #21
GSXR
Registered
 
Drives: K6GSXR750
Join Date: Jan 2013
Location: Long Beach CA USA

Posts: 3
iTrader: (0)

Quote:
Originally Posted by FormerRotor
Quote:
Originally Posted by GSXR View Post
Just out of curiosity, does anyone have the k&n drop in filter? I'm a new member lurking (hopeful future owner) and am surprised at the aftermarket availability (US) of this engine, I'm used to the cold air intakes and the only drop in k&n filters Ive used where on my bike but I have never owned a forced induction vehicle so does anyone know if it would be similar results to remove this foam piece as opposed to getting the k&n drop in? Either way, it is a pretty good free mod
Candidly, I don't think either are really going to give you any gains that would be larger than what could be considered a testing error on a dyno (or even close there-to). Some folks do have k&n, but others believe that the cost of possible reduced particulate filtration and possible oil issues are not worth the possible benefits. Many here in the diesel section cite the Spicer report.

What's keeping you from buying the diesel? we'd welcome you to the dark side
Well I HAD a bike, ate it, broke another collar bone lol and it was going to cost more than a grand to fix the bike minus plastics, it was already salvage so I figured ill just sell it and get a car but waiting till I start work in April when I recover, unless I find the right one, not that many with low miles right now
GSXR is offline  
0
Reply With Quote
      02-01-2013, 10:12 PM   #22
FormerRotor
Major
 
FormerRotor's Avatar
 
Drives: 2011 335d, M-Sport
Join Date: Jan 2012
Location: MD

Posts: 1,436
iTrader: (4)

Quote:
Originally Posted by GSXR View Post
Well I HAD a bike, ate it, broke another collar bone lol and it was going to cost more than a grand to fix the bike minus plastics, it was already salvage so I figured ill just sell it and get a car but waiting till I start work in April when I recover, unless I find the right one, not that many with low miles right now
10-4. Broken collarbone is pretty miserable, but I'm glad you made it out with just that. Good luck finding the ride. It's tough to find exactly what you want with the diesels in the used market, but definitely opt for sports package.

Out of curiousity, why go from a gixer to a diesel bimmer? I would've suspected a pure sports car if its a bike replacement.
__________________

My Picture Threads (Oldest to Newest): 1 2 3
Join BMW CCA! (Use my link and I get credit )
FormerRotor is offline  
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 10:46 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST