[E90Martin]

A month ago, I decided to pull the trigger on doing the muffler delete as I wanted more umph from my exhaust. From the outside and during hard acceleration, it sounded great but the cabin drone was just unbearable. As many have said, its to a point where it's a bit embarrassing when I have people sitting in my car. For me the drone was from 2k-2.4k range, it might be a little different from mine because I put on a Vibrant resonator in place of the old muffler. Anyways, I've searched all over the forums and read every post about drone fix. Tried fitting corks onto the hangers as suggested by a few, did nothing to help (was so desperate i actually fell for it) . Read about Helmholtz resonators (j-pipe) but the calculations were so damn complicated and probably for the cost added together with the muffler delete I could've gotten half of a BMW PE.

Anyways, I read about those sound deadning mats on other forums and did some shopping on Amazon and found a spray type alternative. I got it today, did 2 coats around the area where people would normally put a Helmholtz resonator. boom 90% drone gone, even my steering wheel vibration from the exhaust drone during idling is gone.
Now the only downside of this is that the substance is black, so if you have fancy pipes and do not want to ruin it because you have people looking under your car, i would not suggest doing this. Furthermore, I do not know if this is permanent, as of right now the coat is holding up to the heat but I'm not sure if it would melt on excessive heat (e.g. long trips).

TL;DR
Spray boom mat on exhaust, fix drone

Link to product: http://www.amazon.com/DEI-050220-Boo...words=boom+mat


Note: Please spray at your own risk, do not get mad at me if it does not work for you/ ruins your pipes.

[Route 16]

i read it was flammable.
If this works, I'll spray my pipe, and rewrap it again with exhaust wrap so it still looks clean.

[E90Martin]

Originally Posted by Route 16

i read it was flammable.
If this works, I'll spray my pipe, and rewrap it again with exhaust wrap so it still looks clean.

I'll keep you guys updated if it comes off/ catches fire, i'm not too worried about the flammable part mainly because everything that comes in a spray paint are flammable. Besides, there's not much to burn down there (except for the two corks

Yea you can wrap it with an exhaust wrap to keep it clean, I've also read that the larger area you spray, the more it dampens the sound so I might actually spray a bit more, maybe on the resonator to see if it actually helps.

[Route 16]

Originally Posted by E90Martin

I'll keep you guys updated if it comes off/ catches fire, i'm not too worried about the flammable part mainly because everything that comes in a spray paint are flammable. Besides, there's not much to burn down there (except for the two corks

Yea you can wrap it with an exhaust wrap to keep it clean, I've also read that the larger area you spray, the more it dampens the sound so I might actually spray a bit more, maybe on the resonator to see if it actually helps.

Cool, i like it if it only eliminates drone but doesnt muffle actual exhaust
sound

[7786]

I wonder if wrapping it with something like this would work.

http://www.kineticsnoise.com/industrial/knm100al.html

[E90Martin]

Originally Posted by 7786

I wonder if wrapping it with something like this would work.

http://www.kineticsnoise.com/industrial/knm100al.html

Not sure, but those materials should be quite pricey. I just wanted a quick cheap solution, didn't want to go through too much fuss and spend too much money or else my cost would pile up to an exhaust system.

[Efthreeoh]

Not to be a asshat here, but what exactly do you think the muffler is for? The engineers tune the exhaust to be as quiet while providing proper engine breathing and power.

[E90Martin]

Originally Posted by Efthreeoh

Not to be a asshat here, but what exactly do you think the muffler is for? The engineers tune the exhaust to be as quiet while providing proper engine breathing and power.

not to be an* asshat but there are plenty of people who has done the muffler delete mod. To be honest at this price point the exhaust sounds pretty dam good, the only con was the drone. I'm here giving something that helps cure that con for people who has done this mod and you're giving me shit. Again this whole post aimed towards people who has this mod done and wants to get rid of the drone, not a debate on whether people should get a muffler delete. With your mentality about "the engineers" there's literally no point in modding your bimmer at all, technically everything single part of your car has more R&D and time spent from the factory when compared to aftermarket parts. Welp but that's none of my business.

[Efthreeoh]

Originally Posted by E90Martin

not to be an* asshat but there are plenty of people who has done the muffler delete mod. To be honest at this price point the exhaust sounds pretty dam good, the only con was the drone. I'm here giving something that helps cure that con for people who has done this mod and you're giving me shit. Again this whole post aimed towards people who has this mod done and wants to get rid of the drone, not a debate on whether people should get a muffler delete. With your mentality about "the engineers" there's literally no point in modding your bimmer at all, technically everything single part of your car has more R&D and time spent from the factory when compared to aftermarket parts. Welp but that's none of my business.

I wasn't making comment on whether the muffler delete was worthwhile or not, nor debating if people should mod or not mod. I was making the point that what did you expect to happen when you remove a major component of the exhaust system. It just seems silly to remove the muffler then post a thread on how it makes the cabin drone. Engineers spend hundreds of hours designing exhaust systems to prevent such issues by applying science and engineering principles to the design process. You've modded the car, part of the modification is a change in noise signature of the exhaust. Yup, anyone can mod a car anyway they want with parts developed with a lot of R&D or very little (I'd say cutting off a muffler has no R&D and more of a hope-for-the-best development), but when the mod makes an undesirable (see, got my grammar correct that time) change, what is the point?

[E90Martin]

Have you even read my first post? I am not here to complain about my drone, i'm providing a "solution" to the drone smh. The mod creates a desirable change with a slight drawback, a drawback in which im trying to convey a solution for. God you should just stop replying because your attempt at not being an asshat is really bad. You read the title assuming that this newb here is asking for a solution after chopping off his muffler, but probably reading the post would make you sound less dumb. Please dont lecture me on R&D and engineering anymore, you make it sound like I chop off my muffler just for fun. Like I said before it sounds good, at 1/10 price of a catback system, never at one point have I said the mod outcome was undesirable.
It'd be best if you dont reply to a thread where you have no interest in a solution for something as radical as chopping off a muffler. Hoewever, if you still decide to reply at least read the god damn post or go open a new thead and lecture all the greatness of research and development.

[cdgatti]

Interesting mod. I would say if you can't afford to do a mod correct you shouldn't do it. Correct would have been to replace the muffler with an engineered alternative. If you sprayed the sound deadener on the underside of the car that should help to reduce the noise somewhat, but don't spray it on the exhaust pipes, that could be a fire hazard right under your gas tank. You may have to live with a little drone from this mod. Also you could and probably will see a performance drop off. Our engines are designed to have some back pressure from the exhaust system, by eliminating the muffler you have removed some. I don't really know if it is significant or not though. Doing some half assed mod for your light switch to get the euro rear fogs is a safe thing, but on a bmw we really shouldn't be half assing our exhaust systems, just one man's opinion!

To the op, yes I realize you are trying to provide a solution to the drone for others, but it is the responsibility of the other members here to police these things somewhat so that others can understand the potential downsides of unproven solutions so bad ideas and potentially dangerous ones don't get propagated.

[Route 16]

Originally Posted by cdgatti

Interesting mod. I would say if you can't afford to do a mod correct you shouldn't do it. Correct would have been to replace the muffler with an engineered alternative. If you sprayed the sound deadener on the underside of the car that should help to reduce the noise somewhat, but don't spray it on the exhaust pipes, that could be a fire hazard right under your gas tank. You may have to live with a little drone from this mod. Also you could and probably will see a performance drop off. Our engines are designed to have some back pressure from the exhaust system, by eliminating the muffler you have removed some. I don't really know if it is significant or not though. Doing some half assed mod for your light switch to get the euro rear fogs is a safe thing, but on a bmw we really shouldn't be half assing our exhaust systems, just one man's opinion!

To the op, yes I realize you are trying to provide a solution to the drone for others, but it is the responsibility of the other members here to police these things somewhat so that others can understand the potential downsides of unproven solutions so bad ideas and potentially dangerous ones don't get propagated.

I have 2 baseline dynos and shows the cons of removing 2ndary cats (surprisingly) and muffler delete. 10 hp decrease
Non-muffled sound is cool IMO, I knew I had to live with the drone at some extent. But I do like op's effort to reduce drone, I'm trying to source a helmholtz chamber and weld it along the pipe. But op how hard is it to remove the black spray? I agree, it's a fire hazard and the gas tank is right beneath that and behind the rear seats.

[Blindside_137]

Lol

The muffler delete IMO is THE best sounding exhaust setup for the N52 for the money period. The PE is a joke for how much it costs.

The only downside to the muffler delete is that drone which tends to vary from one car to another. Mine only bothers me from about 2-3k but any other time this exhaust is phenomenal. Going to look into this for sure thanks for sharing.

[Efthreeoh]

Originally Posted by E90Martin

Have you even read my first post? I am not here to complain about my drone, i'm providing a "solution" to the drone smh. The mod creates a desirable change with a slight drawback, a drawback in which im trying to convey a solution for. God you should just stop replying because your attempt at not being an asshat is really bad. You read the title assuming that this newb here is asking for a solution after chopping off his muffler, but probably reading the post would make you sound less dumb. Please dont lecture me on R&D and engineering anymore, you make it sound like I chop off my muffler just for fun. Like I said before it sounds good, at 1/10 price of a catback system, never at one point have I said the mod outcome was undesirable.
It'd be best if you dont reply to a thread where you have no interest in a solution for something as radical as chopping off a muffler. Hoewever, if you still decide to reply at least read the god damn post or go open a new thead and lecture all the greatness of research and development.

Well this sounded like complaints to me:

"From the outside and during hard acceleration, it sounded great but the cabin drone was just unbearable. As many have said, its to a point where it's a bit embarrassing when I have people sitting in my car."

It's a free place here at E90 Post for people to voice an opinion. If you are sensitive to what people post then don't start a thead. Life has risks.

[hassmaschine]

an exhaust wrap would be a much better idea, but it still won't last forever, because it will get wet. at least it won't catch on fire though, and it's pretty cheap. check summit racing, there's tons of products and they're easy to put on.

IMO muffler delete is the equivalent to putting a fart can on your mom's civic, but whatever.. carry on.

[TheSt|G]

This section really tries to out do itself daily with terrible decisions.

rated service temperature range of -40°F to 220°F

Your muffler easily doubles the 220°F temp cap on that product you listed. Get that stuff off your car immediately before you set it on fire and the plastic gas tank right next to it.

Stop being a cheap idiot who is a danger to himself and others.

[cdgatti]

To the original poster - one other consideration if your car does catch fire, the insurance adjuster will most likely determine the cause and not pay.

[E90Martin]

Originally Posted by Efthreeoh

Well this sounded like complaints to me:

"From the outside and during hard acceleration, it sounded great but the cabin drone was just unbearable. As many have said, its to a point where it's a bit embarrassing when I have people sitting in my car."

It's a free place here at E90 Post for people to voice an opinion. If you are sensitive to what people post then don't start a thead. Life has risks.

amazing huh how I managed to solve my own complaint in my own first post. Definitely whole point of my thread, lmao i just stated ur attempt ass an asshat was succesful, more like praising you buddy. What can i say I like to live dangerously, battling with trolls are my main thing.

[E90Martin]

Originally Posted by hassmaschine

an exhaust wrap would be a much better idea, but it still won't last forever, because it will get wet. at least it won't catch on fire though, and it's pretty cheap. check summit racing, there's tons of products and they're easy to put on.

IMO muffler delete is the equivalent to putting a fart can on your mom's civic, but whatever.. carry on.

Thread = Exhaust sound/ Drone
Argument you proposed = Exhaust Wrap
Exhaust Wrap = contain exhaust heat
=????
Sorry I dont get you, nor does my mom drive a civic. However, when she does get one I'll follow your tip and put on a fart can and see if it sounds the same. Anyways, the construction of let's say an active autowerke exhaust's construction is the same as a muffler delete, only with fancier piping and a helmholtz resonator that apparently doesn't remove drone. Before you make that general assumption, you might actually wanna go around and hear people's setup with the mod done.

[E90Martin]

Originally Posted by Blindside_137

Lol

The muffler delete IMO is THE best sounding exhaust setup for the N52 for the money period. The PE is a joke for how much it costs.

The only downside to the muffler delete is that drone which tends to vary from one car to another. Mine only bothers me from about 2-3k but any other time this exhaust is phenomenal. Going to look into this for sure thanks for sharing.

Thank you, someone who actually drives a n52 and does not justify the fact to spend 1/10th of a car's value on an exhaust system. From this past week, all of my friends noticed the reduce in drone, its a lot more subtle and the buzz is gone 80%+. If you're afraid that the car will catch fire and blow up causing a Transformer like explosion that some have suggested, spray it on a small area and wipe it off if it doesnt work for you. People don't seem to understand that nearly everything that comes in a spray can is highly flammable, if anything it's more likely to melt off than sustain a fire that can keep up with wind speeds at 50mph. Anyways though, not jumping into conclusions but definitely give it a shot if you have this mod done.

Cheers

[Efthreeoh]

Originally Posted by E90Martin

amazing huh how I managed to solve my own complaint in my own first post. Definitely whole point of my thread, lmao i just stated ur attempt ass an asshat was succesful, more like praising you buddy. What can i say I like to live dangerously, battling with trolls are my main thing.

Sure.

[Route 16]

I'm getting more and more comfortable with the idea of a 12" vibrant resonator along where the original resonator would be. From the reading I've looked up and I hope it works on my car is to keep the same "loudness" of a straight pipe but reduce driving drone.
Vibrant resonator #1792 is what I would like since it's short and I know I have enough room somewhere but a 12" resonator sounds good and is my length limit, since a longer resonator would "massage" the exhaust pulses longer.