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Intake horn and resonator delete.

26K views 29 replies 13 participants last post by  sixpot_simon 
#1 ·
I finally got around to replacing my tensioner roller before Sandy came with the rain.


As I was buttoning her back up, I noticed a tear in the MAF boot. That's when I decided to go ahead and do the horn and resonator delete. After some searching, I discovered that all I needed was a MAF boot from an E46 323 (p/n 13541705209). This boot is also almost $20 cheaper from the dealer vs. the one with the hole for the resonator box.
Old vs. New (right)

Horn removed

Done.
 
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#2 ·
You probably noticed a little more "edge" to the engine sound. Removing the box also improves air circulation, but it's probably not measurable.

BTW, one can use a plastic pipe cap and a hose clamp to plug the hole. Get one that fits inside the hose.
 
#8 ·
So have you gained anything apart from a more throaty roar? Eg better/worse mpg/power/torque?

Thinking of putting a pvc cover over mine with a clamp but worried heat will sink in through the plastic into the intake boot from there? Also noticed a little trumpet type thing inside the air box? Can this be removed?

Finally are there any other restrictions in the oem air box that I can remove to improve sound guys?

What is the second smaller intake pipe on the air box for entering into the box from the top?

Sorry not familiar with the e39 intake set up!!
Had a few e46s in the past totally different air boxes.
 
#10 ·
So have you gained anything apart from a more throaty roar? Eg better/worse mpg/power/torque?

Thinking of putting a pvc cover over mine with a clamp but worried heat will sink in through the plastic into the intake boot from there? Also noticed a little trumpet type thing inside the air box? Can this be removed?

Finally are there any other restrictions in the oem air box that I can remove to improve sound guys?

What is the second smaller intake pipe on the air box for entering into the box from the top?

Sorry not familiar with the e39 intake set up!!
Had a few e46s in the past totally different air boxes.
I haven't really had a chance to analyze mpg gain/loss.
There is a good write up on the pvc mod if your boot is fine. In my case, I had to get a new one. The trumpet type thing is what I called the intake horn which I also removed. Not sure what else really you can remove and I'm not sure what the second smaller intake pipe is. Hopefully someone chimes in with an answer for that.

I will report back with an mpg analysis when I can.
 
#11 ·
I need to do this. My boot is in a questionable shape and being you can get a factory BMW boot and not have some hacked up mod and remove clutter all at the same time.... doing it! thanks for the part #!!!
 
#12 ·
When I removed my airhorn back a few years ago, I also removed all the baffeling inside the box with a dremel tool. I still have that little PITA box on the side though--every time I tried running the car without it my mileage went the wrong way. So it's still there. As stated over on the other forum, get back with us and let us know how this works for you--might just give it another go.
 
#14 ·
^ Really? Increase in exhaust noise. Unreal...
 
#15 · (Edited)
Got my new boot, part # above... does not fit man. On the MAF side it's about 1/2" too small in diameter. Did you strech it?

After looking into this more I believe you have a 528i, I have a 530i. An E46 330i intake part # 13541438761 is probably what I need. Your part # is from a E46 238i.
 
#17 ·
DAMN IT! LOL. Anyone want to buy the 328i boot?
 
#20 ·
BMW left very little, if any, HP "on the table". The person who said exhaust noise obviously meant engine noise, in general. BMW went to great trouble to make a luxury car, quiet, smooth riding, etc. and the first thing many do is try to add CAI which is a total waste of money and greatly increases chances of water-locking your motor. They delete mufflers and cats, etc. It is their perogative and while not my thing, it just seems ironic to buy a colonial house and try to make it into a ranch style! Why not start with a Rice box if that is sound and ride one is after? However, I can appreciate taking the luxury and making it better to one's taste and retaining much of the great BMW engineering. I'm getting tolerant in old age. Just have thing about those who go too far and steal (for lack of a better word) the peace their fellow drivers around them have a right to enjoy. Nothing is more rude to me that having to listen to someone else's choice of music as they obviously go to great trouble to make it permeate the space of 6 cars in any direction. I draw the line there, but that's just me- I know YMMV and my thought are simply my own. Way I was raised I guess.

Like the other day someone posted that a big dog had the audacity to get in front of their car and they hit it. First thing they did was not even check to see if dog was in pain, dead, or dying. Their only interest was in damage to their bumper which would be there in 10 seconds or 10 days. The dog may have needed help. I stated how disgusting that attitude was TO ME and I was PM'd by driver stating his rebuttle was "everyone has to go sometime???" Excellent thought process.

Back on topic...you will find mods under a few hundred bucks pretty much will yield little or no improvement in HP, torque, etc. I bought a Power Chip (did not pay $1000 bux or whatever they advertised) but paid I think $400. Got rid of Dinan software and went with Power Chips. Why? Because P/C offered a solution to my low air flow from new SAP and valve likely caused by carbon build-up. I bought P/C software just to get European software for SAP system. Got absolutely no driveability improvement except higher RPM limit, speed limit removed, car remains in DSP mode "off" if that is what you chose on last drive, etc. If I was after HP, I would have been highly disappointed. After spending $600+ on all new SAP parts, and getting air flow error, P/C software took care of error allowing a "pass" on Indiana emmission test. Sorry to ramble.. :thumbup:
 
#21 ·
Back on topic...you will find mods under a few hundred bucks pretty much will yield little or no improvement in HP, torque, etc. I bought a Power Chip (did not pay $1000 bux or whatever they advertised) but paid I think $400. Got rid of Dinan software and went with Power Chips. Why? Because P/C offered a solution to my low air flow from new SAP and valve likely caused by carbon build-up. I bought P/C software just to get European software for SAP system. Got absolutely no driveability improvement except higher RPM limit, speed limit removed, car remains in DSP mode "off" if that is what you chose on last drive, etc. If I was after HP, I would have been highly disappointed. After spending $600+ on all new SAP parts, and getting air flow error, P/C software took care of error allowing a "pass" on Indiana emmission test. Sorry to ramble..
This is good information. Had I known I wouldn't have bought a new SAP and valve.
So let me verify it's functions again with you to be cleared.

1/ It bypasses SAP check?
2/ It deletes top speed limit?
3/ It turns OFF DSP traction control???

Please reply, I kind of liking this PC mod.
 
#22 · (Edited)
Quick synopsis as I have posted here before. It was minus 20 degrees at work. Car parked outside. Went to go home at day's end and SES was on. Read code and it was something to do with SAP-low flow, check pump, etc. Began trouble-shooting system. Pump was getting no voltage at start-up. Traced to 50 amp fuse under passenger seat. Fuse #107. Real PITA as passenger seat really needs to slide back into rear seat area. Did not disconnect battery so when I disconnected fine stainless steel wire connected to seat that tells air bag system exactly where seat is relative to front dash, I set an air bag system code I could not clear. Removed pass. seat, removed sill plate, pulled up 1" think insulation and basically 1/2 azz accessed fuse #107, it was blown. Power in, no power out with key on. fuse is a real oddball BMW special. Replaced fuse and re-installed seat. That's when I discovered I had created air bag error by removing wire and air bag system lost calibration of where seat was. Pulled SAP to see if I could see why it had failed. Drilled out rivets, opened pump and water flowed out of pump. Obviously froze that day and fuse blew as excess current was drawn trying to get pump to run with locked rotor. Cleaned pump as well as I could and it ran on bench with old battery, but I did not trust it. Water gets into pump only one way. SAP valve fails sticking open and condensation forms in pump. Water does NOT flow from exhaust to pump through valve. Hot air from exhaust flows "backwards" to pump when pump is not running to overcome exhaust pressure allowed to flow to pump by bad valve. Condensation eventually accumulates and pump fails. Before this day, I had had NO SAP error ever. Ordered new pump, valve, all tubing (from pump to valve), new relay (salmon-colored one in white box (ECU BOX) under passenger cabin air filter, fuse, new tubing leading vacuum to valve, etc. I replaced everythying. Started car, pump ran for about 90 seconds (normal) then shut dowen and I had SES error again. Read it and it was low air flow from SAP. Tried everything then took to BMW. BMW techs charged me nada, but said they could feel strong airflow from pump-just not enough getting to O2 sensors. They said my system was absolutely fine, but I likely had blockage in heads (carbon build-up). $8000 and they said whole system was a joke just to fire cats 60 seconds faster, but BMW needed in USA only to pass government emmissions-many cars do.

So, I had SES light I could never get to stay away. Found out in Europe and elsewhere, low air flow from SAP would NOT throw an SES, but just set a no problem code in ECU in other countries. No issue except places in USA requiring emmission test. They (BMW techs) said my old pump, before it gave up the ghost, may have just had marginally better air flow than new Pierburg which kept error at bay.

I was talking to Powerchips people about a Powerchip for performance-you could negotiate then and $1000 chip was negotiable to $350 or $400. P/C had an "option" you had to ask for which was the European SAP software for a USA car which as long as all the pieces were there in the car as prescribed (pump, valve, power to pump, etc.) the European software would allow a much smaller reaction of the O2 sensors to satisfy the ECU. The O2 sensors must see some lean condition when they expect SAP to be running so you can not just remove everything and go about your business-just less air flow was adequate. New chip cleared error from new pump. I just read recently about an Audi Pierburg pump that is nearly identical to E39 pump (uses same mounting ring, etc.) that is $107 NEW on Amazon. Guy found one at junk yard for $15 and it worked. Remember, always change valve with pump. At least clean it out as carbon builds up in it, diaphram rots, etc. Some can be brought back to life with good cleaning.

I am on 3 years now with chip and new BMW parts. Still HATE system, but it no longer will set an SES light unless system fails. If SAP runs for longer than about 3-4 minutes for any reason (bad relay-stuck closed) it will burn itself up. Pump is running far in excess of what it is designed to run full time. Should only run on cold starts for a minute or so.

BTW, chip made gas pedal feel more responsive, but I would have to bet it added absolutely no HP. Just changed how gas pedal signal was interpreted by ECU. No gas mileage change, but no speed limiter, RPM raised 500 RPM, and if you select DSP "off" it will start on the next ignition cycle still off rather than default back to dsp "on". People talk about sims to defeat SAP, but it was never a thought for me. I wanted a solution and wanted it NOW as if you get ANOTHER ses error, you will never know it if SES is always on. If that is all you care about you could just put black electrical tape over light and forget it. not an option for me. If I had it to do over, I would try Audi pump, and if still low flow, would call Powerchips and tell them you don't care if they do nothing else but give you the non-US software for SAP system and see how cheap you can get chip. :thumbup:
 
#23 ·
Quick synopsis as I have posted here before. It was minus 20 degrees at work. Car parked outside. Went to go home at day's end and SES was on. Read code and it was something to do with SAP-low flow, check pump, etc. Began trouble-shooting system. Pump was getting no voltage at start-up. Traced to 50 amp fuse under passenger seat. Fuse #107. Real PITA as passenger seat really needs to slide back into rear seat area. Did not disconnect battery so when I disconnected fine stainless steel wire connected to seat that tells air bag system exactly where seat is relative to front dash, I set an air bag system code I could not clear. Removed pass. seat, removed sill plate, pulled up 1" think insulation and basically 1/2 azz accessed fuse #107, it was blown. Power in, no power out with key on. fuse is a real oddball BMW special. Replaced fuse and re-installed seat. That's when I discovered I had created air bag error by removing wire and air bag system lost calibration of where seat was. Pulled SAP to see if I could see why it had failed. Drilled out rivets, opened pump and water flowed out of pump. Obviously froze that day and fuse blew as excess current was drawn trying to get pump to run with locked rotor. Cleaned pump as well as I could and it ran on bench with old battery, but I did not trust it. Water gets into pump only one way. SAP valve fails sticking open and condensation forms in pump. Water does NOT flow from exhaust to pump through valve. Hot air from exhaust flows "backwards" to pump when pump is not running to overcome exhaust pressure allowed to flow to pump by bad valve. Condensation eventually accumulates and pump fails. Before this day, I had had NO SAP error ever. Ordered new pump, valve, all tubing (from pump to valve), new relay (salmon-colored one in white box (ECU BOX) under passenger cabin air filter, fuse, new tubing leading vacuum to valve, etc. I replaced everythying. Started car, pump ran for about 90 seconds (normal) then shut dowen and I had SES error again. Read it and it was low air flow from SAP. Tried everything then took to BMW. BMW techs charged me nada, but said they could feel strong airflow from pump-just not enough getting to O2 sensors. They said my system was absolutely fine, but I likely had blockage in heads (carbon build-up). $8000 and they said whole system was a joke just to fire cats 60 seconds faster, but BMW needed in USA only to pass government emmissions-many cars do.
I feel for you, that was one hell of an ordeal to have gone through.:thumbup:

if you select DSP "off" it will start on the next ignition cycle still off rather than default back to dsp "on".
Ah! OK thank you.

I just read recently about an Audi Pierburg pump that is nearly identical to E39 pump (uses same mounting ring, etc.) that is $107 NEW on Amazon.
Good to know thank you. Did you happen to catch the year and model of the Audi?
 
#24 ·
I feel for you, that was one hell of an ordeal to have gone through.:thumbup:

Ah! OK thank you.

Good to know thank you. Did you happen to catch the year and model of the Audi?
I am looking because when I read the post, I could not believe there were very few replys or comments and a SAP pump new for just a tick over $100 I felt was greatest revelation since air conditioning! When I find, I will post.
 
#25 ·
it might have been this one on Amazon. I was wrong in that it is not a Pierburg, but should put out plenty of air if car is not clogged with carbon as mine was. I believe you use your mounting ring. I would verify electrical connections to make sure hot is to hot and ground is to ground, but as you can see everything looks VERY similar and as I reall it was used on a LOT of Audi A4s. Now, find on at a junk yard and you can really save some bucks.

http://www.amazon.com/00-07-06A9592...dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1
 
#27 ·
^ Agree. But this mod of using a E46 MAF boot does not take away from the car. It's a BMW part, fits and looks OEM. I got my 330i boot in last night. 2 minutes of work. Opens up the engine bay. Touch of intake noise isn't going to put hurt'n on my blue blood image. :)
 
#29 · (Edited)
^ the question of how he likes his car cooked. Over stock with a side of relability and cup of boring. JP. But After mod'n cars and being a gear head for over a decade all I can say I think LONG and hard before doing a mod to a car now. And I always try and use OEM parts before aftermarket. I can't stand cars that are mod'd and eveything is needing f'k with every 3 days. I don't miss those days. This mod involves nothing permanent or expensive to revert. BMW part. Looks stock. Does not compromise reliability. I give this a mature gear head thumbs up.
 
#30 · (Edited)
An insight on my attitude heading into this trial: normally I do not believe in removing parts which BMW have painstakingly included for a reason. Nor can I see how a device which smooths the intake airflow can have a negative effect. Buuuuuuut...

What I have observed is that removing the intake horn has noticeably improved throttle response :confused:, especially the first stab of the throttle to get some revs for a hill-start. Also, the idle stabilisation is a lot better, for example there is much less hunting when slipping the clutch to slowly reverse into a parking space that is on an incline.
 
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