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YOUR RESEARCH$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
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Use shaving cream cap
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$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
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Leading evidence: 'Use shaving cream cap' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Adjust flow quality of the air moving through the intake' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Adjust flow quality of the air moving through the intake
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Suggestion
2) To adjust the flow quality of the air moving through the intake.
$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
Adjust sound quality of the intake
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$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
Replace anymore
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Suggestion
Just don't think it's something worth changing anymore for me.
$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
Replace ecu
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Suggestion
The fact that BMW would use them with or without seems to support the thought that it is totally performance neutral (unless BMW changed the ECU to account for differences).
$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
Replace ecu
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Suggestion
The fact that BMW would use them with or without seems to support the thought that it is totally performance neutral (unless BMW changed the ECU to account for differences).
$2 Airbox Mod: the easiest, quickest, cheapest, most reversible method
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A few weeks back I️ asked about getting a more satisfying induction sound. Lots of you directed me to many threads on the process. I️ wasn�t happy with any of the mods in older threads so I️ went to the local home improvement store to devise my own. I️ think I found the best way possible to get rid of the resonator, get the sound, and have it still be easily reversible. All it takes is a few dollars (literally). Go and get an 1 1/2� ABS trap adapter and a female 1-1/2� cap. Take the top off the airbox and remove the resonator. Put the threaded end of the trap adapter into the airbox and thread on the cap until it�s tight. Put the top of the airbox back on and put the hose over the adapter and tighten the clamp. Five minutes, two bucks, and you�re done. Best of all, since the ABS matches the airbox, nobody can tell it is anything other than stock. See pics below:
I found that my 04' 996 was less responsive when I blocked off the resonator - I have a Cargraphic exhaust so I couldnt hear the intake over that anyway
Haven�t noticed any lack of response and I️ have the Fister mod. The induction noise is there and isn�t as pronounced as it would be with stock exhaust, but it�s like adding a necessary instrument to a symphony.
With 200cel xpipe + mufflers I felt the power delivery was dull, may have just been my experience.
Im still of the opinion that the resonator box does more that cancel out sound. It also helps smooth air pulses for the MAF to read.
I️ considered something of that sort but decided against it. I️ think that heat cycling that kind of plastic might eventually cause it to get brittle and crack. I️ think The PVC will last the life of the car.
It would be interesting to conduct a poll to see if people that have tried it found the car to run a) the same, b) better, c) worse
And maybe a second question about whether they kept the mod in or eventually removed it.
I�d guess none. It�s closed, so all that could possibly happen would be a lowering of the pressure in the tube/resonator. What that pressure does to the rest of the intake track is a question for the engineers. It�s sole purpose is to cancel out sound waves emanating from the intake side of the motor. By removing the resonator you are removing the sound frequencies that cancel out the ones some of us want to hear.
I have a similar mod blocking this off, and I like it. It runs the same; no loss in power, I think it sounds good, and I don't have plans to take it out.
Accurate. As long as you do not remove the resonance cavity from the airbox, the system is sealed.
Here's what a Helmholtz resonator actually does and some background, if anyone is curious...
https://people.seas.harvard.edu/~jon...helmholtz.html
The resonator does not make power or prevent power from being made - it just amplifies sound within the resonant frequency range of the resonator.
Translation please? I read it and am not sure I got it. Is it basically saying that the resonator makes it easier to hear the specific tone(s) that it is tuned to?
For those wondering what it does, here is a video that best exemplifies the sound that is uncorked. If you have stock exhaust it is more prominent. If you�ve got an aftermarket exhaust or fister mod it adds to the overall package. It�s really not noticeable until about 4K RPM with heavy throttle.
You Tube
Yea, you didn't get it because it really doesn't apply. In the instance described, the Helmholtz is used to "amplify" a particular tone, BUT It can also be used as a "canceling sound wave" to cancel an unwanted sound, which is the way it is tuned in the Porsche intake system. Porsche thought canceling the unwanted sound was preferred, ( or maybe it was to meet some drive-by sound tests), but I actually prefer the "uncancelled sound"..
True, there is no power performance benefit, but the sound is as much a part of the driving experience as handling and power,and looks. The reason Porsche spends millions R&D and hires acoustics engineers.
No, it's the automotive equivalent of taking the knobby tires off your enduro motorcycle and put street tires on because you only like to drive on the street.
Actually, modern cars
do
put playing cards in the spokes ->
https://www.caranddriver.com/feature...ned-tech-dept/
Modern cars are Milli Vanilli, plugging a factory resonation port is "
too legit to quit
".
.
Is there a definitive answer on the reason for the existence of the resonator? It has at least 2 possible functions:
1) To adjust the sound quality of the intake. In this case, messing with it would be purely a matter of preference on what you like to hear.
2) To adjust the flow quality of the air moving through the intake. In this case, messing with it could have an impact on engine performance.
I wouldn't be too quick to rule out item 2. Isn't it possible that this device serves a function to improve airflow into the engine at a particular frequency (RPM) range?
It's the Porsche equivalent of adding a fake nitrous purge kit to your otherwise stock "sporty" import.
To be a _proper_ 996 "butt dyno" mod, it needs to cost money AND be useless - so those shaving cream caps aren't good enough. For full street cred, you must spend at least $400 and have the dyno sheets to prove a loss of at least 5 HP.
Bonus points will be awarded if you can provide IR footage of your "cold air" intake actually running hotter than the stock airbox.
Something I found interesting when I was replacing the intake boot on my e39 5 series.
The e39 uses the same engine as the e46 3 series but the 5 series boot has a Helmholtz box and the 3 series doesn't. With the different demographic between the 5 & 3 series buyer, I guess BMW decided that the less genteel e46 owners didn’t need/want their wooosh silenced. I went with the 3 series boot because it freed up a lot of room to access other things in the engine compartment.
5 series on the left and 3 series on the right.
The intake sound seems like it is a
lot
louder on that 997 video in post #17 -- is it really that much louder after the mod? (or is part of that sound due to his sport sport exhaust?)
Interesting. The fact that BMW would use them with or without seems to support the thought that it is totally performance neutral (unless BMW changed the ECU to account for differences).
I remember reading an article from one of the 996 designers saying they went through great lengths to make the 996 engine sounds reminiscent of the predecessor air-cooled cars. With the 996's 4 valve heads, vario-cam, and dual intake chamber ram-charging, all creating the "Banshee Scream" above 5k, the Helmholz was meant to cancel that sound and be more like the predecessors.
The air-flow does pulse rapidly and the Helmholtz does smooth the air-flow, but it has no effect on the amount/mass that is inhaled or the measurement. Our MAF sensors only read in one direction and are not effected by reversion (reverse flow). There are some MAF designs that are effected by reversion and will read flow no matter the direction, but Porsche does not use this type.
SORRY, But NOTHING sounds like an AIR COOLED PORSCHE.
I remember that sound...having owned 4 of them year ago....
The only thing that comes close, not the same, but...sitting in a front engine FERRARI and turning the key....sounds like it isn't going to start...then VROOOOM...it goes right up your back.
I agree that the 996 doesn't sound as much like the air-cooled cars as Porsche would have liked, but I actually prefer the "Banshee Scream" of the uncorked 996's. I get tired of loud exhausts and just enjoy the sound of the intake resonance when nearing red-line.
You can never get the same sound as an air cooled engines. The water jacket changes it it so much that no amount of sound tuning will get it to come anywhere close to it. I personally don't like the aircooled sound. They sound like a beetle.
These air cooled comments are interesting. What gave me the bug to do this was watching Chris Harris flogging a newer GT3 and hearing the intake sound in the cockpit. I️ could hear it in the 996, but very distant. This mod brings it more to the forefront. While I️ grew up with posters of air cooled 911�s on my wall, I�d never heard one. I️ think the newer GT3�s sound better.
I personally subscribe to the 'it does more than muffle noise' maybe it's just my butt dyno but I felt my car was slightly less responsive. Maybe the DME didn't adapt? Maybe it didn't need to? Not sure but here is some documentation:
I even bought the aluminium block off from Denmark to try!
Just don't think it's something worth changing anymore for me.
No wonder! You need the solid platinum plug from Norway to really feel the massive power increase!
Great info in your post. I'm a bit of an originality freak, but kind of on the fence to try this. I think your post has talked me out of it.
Don't read more into the technical description than it actually says. Yes the "muffler" does help smooth the pulses and create a more linear measurement, BUT that does not say that it means more/less power.
I think that's what this is about. The sound.
Presumably the oil might get used, so there is that. I'll have to look around, I might even have a cap from a quart of liquid death .
I'd agree - doesn't add any power but for be it changed how they power delivery felt. Maybe similar to a LWFW - doesn't add power - just changes how it's delivered.
I've had other friends tell me their 996 feels 'smoother' with it.
This is a source reference. Confirm exact model applicability in the original material.
