Sound Deadening Model 3

[superbaka]

I think the next step would be to replace the suspension bushings where the noise is transmitted to the chassis (this is the source of that rumbling that you can't get rid of on poor road surfaces). In racing, we'd replace the bushings with the hardest, stiffest ones available to transmit the best road feel to the driver. But in something that isn't a racecar, you want something that is far softer to reduce NVH and increase comfort - albeit at the expense of "handling".

MPP is offering new bushings, but not sure if they would help with NVH.

 

[d900929]

@Pied - how much of a difference did dynamat in the wheel wells make?

 

[Pied]

@Pied - how much of a difference did dynamat in the wheel wells make?

The first week, I removed the fender liners and added dynamat for all 4 wheel wells, removed frunk, added dynamat on the strut area, and some thinsulate. I used 4 sheets. Didn't notice any difference.

The next week I removed the trunk liner used ~3.5 sheets of dynamat. Also shoved thinsulate in the side panels. After that, it was noticeable the noise was reduced/muffled.

I didn't cover every inch with dynamat, just cut it slapped it in places I could. I see others do really nice coverage, but I don't have patience for that lol. I didn't take much pictures since I was trying to get everything done. Pic of rear wheel well and the frunk cover.

 

[BMW740iL]

how many sq meters of material did you use?

 

[Pied]

how many sq meters of material did you use?

Not sure, but the roll from Amazon is way too much. I used maybe a 1/4 at most.

 

[bpobill]

The first week, I removed the fender liners and added dynamat for all 4 wheel wells, removed frunk, added dynamat on the strut area, and some thinsulate. I used 4 sheets. Didn't notice any difference.

The next week I removed the trunk liner used ~3.5 sheets of dynamat. Also shoved thinsulate in the side panels. After that, it was noticeable the noise was reduced/muffled.

I didn't cover every inch with dynamat, just cut it slapped it in places I could. I see others do really nice coverage, but I don't have patience for that lol. I didn't take much pictures since I was trying to get everything done. Pic of rear wheel well and the frunk cover.
View attachment 501214 View attachment 501215

I cant imagine going through the time and expense of dynamat and just slapping random pieces like that.... Why even bother??

 

[XLR82XS]

So do we have a solid list of ideas? Do the newest production model 3s seem more quiet? I hear they are and I want to know why.

My 20 is quieter than the 19. The only thing visible without taking crap apart is the rear wheel liners are a bit different in design and the window seals are stiffer.

 

[Occhis]

My 20 is quieter than the 19. The only thing visible without taking crap apart is the rear wheel liners are a bit different in design and the window seals are stiffer.

Interesting. So the wind noise around the doors is much improved?

 

[adrianp89]

Not reading thru this but noticing people using dynamat. That is not the solution to road noise. That task is up to MLV. However with dynamat, you only need 25% coverage.

 

[dfwatt]

MPP is offering new bushings, but not sure if they would help with NVH.

Doubtful. If anything they may cause some increase in NVH.

 

[BioSehnsucht]

My 20 is quieter than the 19. The only thing visible without taking crap apart is the rear wheel liners are a bit different in design and the window seals are stiffer.

Are the differences enough that it would be obvious from photots? I'm curious what changed.

 

[ZapCarM3]

Are the differences enough that it would be obvious from photots? I'm curious what changed.

Wish they had a changelog. Could be a significant improvement just from things being aligned better. Probably other factors but that could be a big one.

 

[dfwatt]

Wish they had a changelog. Could be a significant improvement just from things being aligned better. Probably other factors but that could be a big one.

I wish they had a changelog too but I am extremely skeptical that a significant Improvement came from just tightening up alignments. I've spent dozens of hours reducing noise levels in my car and I can tell you that the problem is not that things are misaligned. The car needed double door seals, reduced glass panel gaps or at least filling in of those gaps, better control over noise getting in through the wheel wells and better control of wind noise around both the a-pillars and road and tire noise coming from the from the rear suspension and trunk area. If you take care of those areas you can knock conservatively 5 to 6 DB off of Highway noise levels. Both our cars are significantly quieter than they were stock. I'd love to compare their noise levels with a sound meter with the 2020 version of the model 3.

 

[ZapCarM3]

I wish they had a changelog too but I am extremely skeptical that a significant Improvement came from just tightening up alignments. I've spent dozens of hours reducing noise levels in my car and I can tell you that the problem is not that things are misaligned. The car needed double door seals, reduced glass panel gaps or at least filling in of those gaps, better control over noise getting in through the wheel wells and better control of wind noise around both the a-pillars and road and tire noise coming from the from the rear suspension and trunk area. If you take care of those areas you can knock conservatively 5 to 6 DB off of Highway noise levels. Both our cars are significantly quieter than they were stock. I'd love to compare their noise levels with a sound meter with the 2020 version of the model 3.

I think tighter alignment would matter more in some areas than others but I have no idea where the issues are coming from.

How did you deal with the glass panels? I plan to put some deadening insulation in the doors with a friend of mine who is a mechanic at Tesla.

 

[dfwatt]

I think tighter alignment would matter more in some areas than others but I have no idea where the issues are coming from.

How did you deal with the glass panels? I plan to put some deadening insulation in the doors with a friend of mine who is a mechanic at Tesla.

Here's the list of what we did to both cars:

1) Dynamatted all four doors and complete trunk area using Noico 80 mil
2) applied Dynamat (Noico) to front strut and shock Tower areas
3) used neoprene tubing around all glass gaps including rear window section
4) doubled up on door seals all the way around using Z and P type neoprene seals (per thread on this)
5) installed sun shades on both roof and rear glass. This made a surprising difference, despite the fact that these aren't even solid fabric.
6) sound dampening foam on inside of wheel liners
Collectively, this stuff made a 6db difference on one car and 5db on the other. Not sure what the 1db difference is but one car had a bit more Dyna matting. Wish I had done pre and post testing for all the interventions but that would have been a lot of extra work and I was just trying to get through all this stuff. Made a big difference though in terms of the stereo. Now at 75 miles an hour on the highway I don't hear anything except the stereo if I Crank It Up just a little bit. Previously I had to turn the thing all the way up to drown out the road and wind noise. Combined with modifications to the stereo system , it's made the Cars a lot more enjoyable on long trips.

 

[cucubits]

Not sure what the 1db difference

dB scale is logarithmic. A 3dB difference would be perceived as almost twice as loud/quiet.

 

[dfwatt]

dB scale is logarithmic. A 3dB difference would be perceived as almost twice as loud/quiet.

Thanks for that clarification. As someone in the Sciences for my entire life I did not know that! Kidding.

Actually subjectively twice as loud is 10 DB. 1 DB is the minimum perceivable increment. 3 DB is a doubling of power. But it does not sound twice as loud. Hope that's helpful.

 

[BioSehnsucht]

Here's the list of what we did to both cars:

1) Dynamatted all four doors and complete trunk area using Noico 80 mil
2) applied Dynamat (Noico) to front strut and shock Tower areas
3) used neoprene tubing around all glass gaps including rear window section
4) doubled up on door seals all the way around using Z and P type neoprene seals (per thread on this)
5) installed sun shades on both roof and rear glass. This made a surprising difference, despite the fact that these aren't even solid fabric.
6) sound dampening foam on inside of wheel liners
Collectively, this stuff made a 6db difference on one car and 5db on the other. Not sure what the 1db difference is but one car had a bit more Dyna matting. Wish I had done pre and post testing for all the interventions but that would have been a lot of extra work and I was just trying to get through all this stuff. Made a big difference though in terms of the stereo. Now at 75 miles an hour on the highway I don't hear anything except the stereo if I Crank It Up just a little bit. Previously I had to turn the thing all the way up to drown out the road and wind noise. Combined with modifications to the stereo system , it's made the Cars a lot more enjoyable on long trips.

Can you elaborate on the neoprene tubing around glass gaps?

 

[ZapCarM3]

Here's the list of what we did to both cars:

1) Dynamatted all four doors and complete trunk area using Noico 80 mil
2) applied Dynamat (Noico) to front strut and shock Tower areas
3) used neoprene tubing around all glass gaps including rear window section
4) doubled up on door seals all the way around using Z and P type neoprene seals (per thread on this)
5) installed sun shades on both roof and rear glass. This made a surprising difference, despite the fact that these aren't even solid fabric.
6) sound dampening foam on inside of wheel liners
Collectively, this stuff made a 6db difference on one car and 5db on the other. Not sure what the 1db difference is but one car had a bit more Dyna matting. Wish I had done pre and post testing for all the interventions but that would have been a lot of extra work and I was just trying to get through all this stuff. Made a big difference though in terms of the stereo. Now at 75 miles an hour on the highway I don't hear anything except the stereo if I Crank It Up just a little bit. Previously I had to turn the thing all the way up to drown out the road and wind noise. Combined with modifications to the stereo system , it's made the Cars a lot more enjoyable on long trips.

Yeah testing after each change would have been cool to know what made what difference.

 

[dfwatt]

Can you elaborate on the neoprene tubing around glass gaps?

I used two different types. I used the RPM Tesla wind noise reduction kit which is basically hollow neoprene tubing that just wraps around the roof glass and then I used some solid .25 inch tubing to fill the other channels that I got on Amazon called "trim lok cord stock rubber seal tubing." The solid tubing filled in gaps where the RPM Tesla kit couldn't. Combination made a significant difference. Others have measured this at something like 3 DB noise reduction. RPM Tesla claims 5 to 8 DB noise reduction just for their kit alone without the supplementing that I did. I think this is generous, but for sure this is a fruitful issue to address, and you can make a significant difference for little money spent.