Model 3 Road Noise

[enemji]

okay, had couple of hours spare earlier to be in my shed.

NOTE - I did over do the C-pillar edges and had to trim some materials off before the panel can be re-fitted flushed (the pictures shown is before I did that final trim..). Not sure if this is different to yours @enemji but my 2022 MIC RWD does some PU foam on the inside of the boot / trunk linings, both sides and bottoms. I remembered when I did the lower boot / trunk compartment LED extension they were on the bottom of the trunk lining but not the bottom tub.

Quick drive around the block seems to have ease the lower frequency road noise but probably did nothing to the suspension impact noise. Then again, that could do with more around the top of strut and the spring isolator.

(Right rear wheel arch)
View attachment 916688


(Left rear wheel arch)
View attachment 916689

(The two wheel arch panels)
View attachment 916690

Yes, even my 2022 M3 has the PU on the trunk liner but it is not facing the cabin side. It is facing the inside of the trunk space.

From what I have gathered thus so far (academic studies on google), a 2” lining of fiber insulation is the optimal thickness and that is why I used a 1” thick fiber roll, one layer on the wheel well and one layer behind the seat panel.

As far as suspension thumps, they are definitely a defining character of the car like any other sports car. All I can say is that the annoying tire noises that were coming through are attenuated.

What is it that you used? Is that Mass Loaded Vinyl? That was good for reducing resonance and deflecting sound, and and not as good for absorbing sound.

 

[enemji]

So I went ahead and did the rear wheel insulation on my second M3 which has the Michelin MXM4 tires. They are very noisy on the concrete roads here, especially compared to the Kinergy GT that are on my other M3. I took it out for a spin and OMG. At the 70mph speed it was almost as quiet and comfortable as the Mercedes with the subdued road noise. 2" of Fiber insulation over the rear wheel well is the way to go! Google University is the best.

 

[XPsionic]

So I went ahead and did the rear wheel insulation on my second M3 which has the Michelin MXM4 tires. They are very noisy on the concrete roads here, especially compared to the Kinergy GT that are on my other M3. I took it out for a spin and OMG. At the 70mph speed it was almost as quiet and comfortable as the Mercedes with the subdued road noise. 2" of Fiber insulation over the rear wheel well is the way to go! Google University is the best.

That's great! It's there anywhere in the front end of the car that the insulation could go into?

 

[enemji]

That's great! It's there anywhere in the front end of the car that the insulation could go into?

Not needed. The rear wheel well is the real root cause of the cabin noise

 

[bmalbert22]

That seems to be the biggest issue I have. For the life of me I cannot isolate any wind noise that seems excessive at high speeds. But I do get a lot of road noise. I've got pillows in the frunk and trunk and want to try the fiber insulation on the rear wheel wells. What other fixes have been best for cutting down on road noise (as opposed to wind noise)?

 

[bmalbert22]

Also, WTF is up with the giant cutout that I have under the speaker grille on the rear deck?! It's open to the trunk below which seems insane from a road noise perspective given how much louder the road noise usually is in a car when you put the rear seats down!

 

[enemji]

Also, WTF is up with the giant cutout that I have under the speaker grille on the rear deck?! It's open to the trunk below which seems insane from a road noise perspective given how much louder the road noise usually is in a car when you put the rear seats down!

I don’t have that cutout. Which model year is this?

 

[enemji]

That seems to be the biggest issue I have. For the life of me I cannot isolate any wind noise that seems excessive at high speeds. But I do get a lot of road noise. I've got pillows in the frunk and trunk and want to try the fiber insulation on the rear wheel wells. What other fixes have been best for cutting down on road noise (as opposed to wind noise)?

Front wind noise was resolved using the weatherstrip on the A-Pillar & front door leading edge (courtesy of researching with Mercedes).

Rear wheel noise is resolved with the 2 inch thick fiber insulation in the rear seat side panels that cover the rear wheel well. That has a NRC of 0.95.

@elonmusk need to hire me. Now!!!

 

[bmalbert22]

I don’t have that cutout. Which model year is this?

2018. They made some changes to this in later model years. But I was surprised when I found this. First thought was that something was missing!

 

[XPsionic]

Not needed. The rear wheel well is the real root cause of the cabin noise

Oh ok, how much material did you end up using? What other materials would work that has less risk of little bits of fibre or dust scattering in the cabin?

 

[enemji]

Oh ok, how much material did you end up using? What other materials would work that has less risk of little bits of fibre or dust scattering in the cabin?

This ceramic fiber was my best option. Regular fibreglass is very itchy and flies around and I did not want to fool with that. This was a well made 1” thick roll, and also tested beautifully against the road noise that I replicated in my home speaker system. Other foams, sponges and rubber/vinyl mat was no match to its sound absorption capabilities.

 

[enemji]

Not needed. The rear wheel well is the real root cause of the cabin noise

Just to confirm, does the mat under your pedals have a 2” thick foam? Mine does. If not, you may want to put that fiber mat there under the carpet.

 

[enemji]

2018. They made some changes to this in later model years. But I was surprised when I found this. First thought was that something was missing!

Ughh. Stick a fiber mat under that opening. That would take care of it.

 

[enemji]

I drove to work today and it was just like I was going to work in my Mercedes. Ooh la la…. This is now a true Luxury Sports car

 

[XPsionic]

I drove to work today and it was just like I was going to work in my Mercedes. Ooh la la…. This is now a true Luxury Sports car

awesome, what's the sq ft of material we should get to get the same coverage as what you did in the rear of the car?

 

[enemji]

awesome, what's the sq ft of material we should get to get the same coverage as what you did in the rear of the car?

I ended up using 2 rolls of this for two M3. So 1 would work for 1 car.

Lynn Manufacturing Kaowool Ceramic Fiber Insulation, 1" Thick x 16" x 48", 2400F Fireproof Insulation Blanket, 3026E

https://a.co/d/4RWT6ON

 

[Ernest H]

Yes, even my 2022 M3 has the PU on the trunk liner but it is not facing the cabin side. It is facing the inside of the trunk space.

From what I have gathered thus so far (academic studies on google), a 2” lining of fiber insulation is the optimal thickness and that is why I used a 1” thick fiber roll, one layer on the wheel well and one layer behind the seat panel.

As far as suspension thumps, they are definitely a defining character of the car like any other sports car. All I can say is that the annoying tire noises that were coming through are attenuated.

What is it that you used? Is that Mass Loaded Vinyl? That was good for reducing resonance and deflecting sound, and and not as good for absorbing sound.

No not MLV, but had some spare foil closed cell PE foam to test. now that I can confirm it does make some difference, it would be a matter of testing different materials and see which is best to apply to the rear wheel arch.

 

[GermanGuyUS]

Front wind noise was resolved using the weatherstrip on the A-Pillar & front door leading edge (courtesy of researching with Mercedes).

Rear wheel noise is resolved with the 2 inch thick fiber insulation in the rear seat side panels that cover the rear wheel well. That has a NRC of 0.95.

@elonmusk need to hire me. Now!!!

I see in your previous post that you applied the z-weatherstrip to the front door leading edge but where did you apply the weatherstrip to the a-pillar?

 

[enemji]

I see in your previous post that you applied the z-weatherstrip to the front door leading edge but where did you apply the weatherstrip to the a-pillar?

Leading edge of front door from inside

 

[3P TGV]

I ended up using 2 rolls of this for two M3. So 1 would work for 1 car.

Lynn Manufacturing Kaowool Ceramic Fiber Insulation, 1" Thick x 16" x 48", 2400F Fireproof Insulation Blanket, 3026E

https://a.co/d/4RWT6ON

My only concern is the warning label associated with the product. under the product description in the listing on Amazon.

DANGER	All ceramic fiber products have a hazard communication warning label and prop 65 warning for airborne fiber inhalation. Please consult the Safety Data Sheet for more information.
HAZARD STATEMENT	Prolonged and repeated exposure to ceramic fiber dust is suspected of causing cancer and other lung damage. May cause skin and eye irritation.
PRECAUTIONARY STATEMENT	When handling ceramic fiber we recommend protective gloves, safety glasses and long sleeve clothing. Avoid creating airborne dust, by only using hand tools. Frequently clean the work area with HEPA filtered vacuum or wet sweeping to minimize the accumulation of dust. Do not use compressed air for clean-up. Avoid breathing the dust and if necessary, wear an approved respirator mask.
SAFETY DATA SHEET	Upon request we can provide the full SDS sheet for these products.

Probably a bit over dramatic on the part of the manufacture to state this (prop 65), but it should be noted. I wish we could find a more natural fiber that worked just as well. Maybe sheep's wool? It is used a lot for insulating Sprinter camper vans and others.

Van Insulation Products

Havelock Wool is Healthy, High-Performance Van Insulation. High R-Value, moisture management, sound absorption. Learn more today.

havelockwool.com