Sound Deadening Project

[tibwolf]

Here's what the rear wheel well looks like without the liner. I had the car jacked up enough to unload the rear springs and get more working space.

I used 1.25sqft total. 5 squares of a quarter sqft each.

One piece was adhered to the inside of the top inner portion of the fender. The black piping is plumbing to the fuel tank.

Here's the liner with thinsulate glued to the back. This is the thicker SM600L which expands up to around 1.6" over time. I ended up trimming portions near the bottom of the liner and the liner around the rear shock. Helps to work the holes with a screwdriver or scissors before reinstalling the liner.

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[johnloov]

Thanks man!!!!

 

[johnloov]

Here's what the rear wheel well looks like without the liner. I had the car jacked up enough to unload the rear springs and get more working space.

I used 1.25sqft total. 5 squares of a quarter sqft each.

One piece was adhered to the inside of the top inner portion of the fender. The black piping is plumbing to the fuel tank.

Here's the liner with thinsulate glued to the back. This is the thicker SM600L which expands up to around 1.6" over time. I ended up trimming portions near the bottom of the liner and the liner around the rear shock. Helps to work the holes with a screwdriver or scissors before reinstalling the liner.

1) Should I unscrew all these and remove all these plastic clips
2) How did you remove these plastic clips without breaking them? I tried one with Philips and it snapped easily.

 

[johnloov]

How do we get these off without breaking them, I tried to use my plastic tool, and they just break instantly.

 

[johnloov]

Got it, this tool works, Philips just snaps them clean easily

 

[tibwolf]

I used the split end pry tools like the bottom one. Slip the two little prongs under the middle circle and it pops right out. Single tooth pry tools and screwdrivers tend to put uneven force on the plastic clip heads and break them.

You can get replacement clips for pretty cheap like these

There are something like 8 screws. You have some front, some back, one under the bumper, and two or three on the inside of the fender. You kind of need to unscrew these ones blind unless you remove the wheel.

 

[johnloov]

I used the split end pry tools like the bottom one. Slip the two little prongs under the middle circle and it pops right out. Single tooth pry tools and screwdrivers tend to put uneven force on the plastic clip heads and break them.

You can get replacement clips for pretty cheap like these

There are something like 8 screws. You have some front, some back, one under the bumper, and two or three on the inside of the fender. You kind of need to unscrew these ones blind unless you remove the wheel.

How do you remove this hose attached to fender

 

[tibwolf]

Not sure on that one. I only removed the rear half of the front fender liner. It was enough to bend the liner, apply CLD to the liner and fender, and glue some Thinsulate. When I buttoned things back up, I stuffed some more thinsulate in the wheel well from the small opening when the hood is up.

 

[tibwolf]

Quick analysis of what sound levels are like in the car:

The left image shows what my phone captured while sitting on the charger without a case. I was going 70 on a medium coarse highway in 6th with cruise control. This is the loudest highway I can think of nearby that doesn't have potholes or road imperfections. The blue line shoes the individual maximum recorded sound levels over a 30 second period. The red line is sound levels at the instant I took the screenshot.

On the right I tried to capture a control "no sound," with the car off and me completely silent. I was parked, baking in the heat.

Decibel math is a little annoying to perform, but hopefully this gives people an idea of what ~20 hours of work and about $500 total of CLD and thinsulate gets you.

 

[ProjectDD]

I will likely never add any sound deadening to my FL5, but I'm really enjoying this thread. Great job on the documentation, specifically the measurements. Whether it's difficult to interpret or not, having actual measurements is great.

 

[johnloov]

le annoying to perform, but hopefully this gives people an idea of what ~20 hours of work and about $500 total of CLD and thinsulate gets you.

Nice which app is this?
I'll try take some readings also.
I'm doing all 4 wheel wells today, and will go overkill again to get a conclusion soon.

 

[tibwolf]

Nice which app is this?
I'll try take some readings also.
I'm doing all 4 wheel wells today, and will go overkill again to get a conclusion soon.

I’m using this one
https://apps.apple.com/app/id1245046029

 

[johnloov]

Updated photos of project.
I’ll talk about the results next

 

[Shingo Shoji]

I put sound deadening in the doors and rear hatch floor of my old FK8. Loved it. Also, makes closing the doors feel like a high end vehicle. I want to do it on the FL5

I've done it and I highly recommend it. A little quieter and much better feel to the door closing. Also stops any vibration from the speakers.

 

[johnloov]

I am absolutely blown away by the results, more than in many ways, and I am very puzzled by some of the outcomes. I love it!

1. The car is now much quieter, extremely well-dampened, and insulated. It's now better than a 2023 Mercedes E-Class in road noise damping, which is very impressive. The decibel meter's don't tell much of the story at all.
2. The wheel well soundproofing and dampening really worked, on top of the interior modifications. I was obsessed, knocking on every panel in the wheel wells and applying product to areas that sounded tinny. The db's look similar to before I did the wheel wells, but for sure the wheel wells did soften the wheel drone.
3. The doors close like a vault. It was well worth it. You can't hear noises from other cars. Even firetrucks are harder to hear!
   
   
4. The car drives way better! This I still don’t fully understand!
5. The stereo sounds crystal clean, bass response is very clean and precise.

Here's some one handed driving, while holding the iPhone. You'll notice you don't hear anywhere as much of the tire noise anymore.







I’ve had 2-3 people in the car and driven on the exact same roads, aggressively in the canyons, adding another 400 lbs! The Type R was bouncing all over the place in the canyons, and I had to constantly switch between modes.

I am totally puzzled by this. The Type R mode now feels perfect? How is this possible?

I only added maybe 80-90 lbs in total at most, and I can’t figure out if it’s the weight or the location of the weight? Or is it the dampening, or just a combination?

But it can’t be just the weight; I’ve had way more weight in the car—400 lbs extra—and the wheels were pogo-sticking all over... Or is it some kind of dampening of the oscillations coming from the chassis?

I don’t get it.

The car feels much more glued to the ground, and it feels way better.

Now, I’m starting to hear other areas in the cabin buzzing and other sounds in the car that I never noticed before, due to all the road noise that used to be in the car.

I was super skeptical about solving the noise issue, and ruining the car.

I am honestly shocked with the results, and will find out how she performs on Laguna Seca this week.

I freaking love this modification.

Drives like a dream now.

At IDLE in traffic:

At 60MPH on the same highway. The DB meter shows similar results to before I sound proofed the wheel wells. But, it did for sure help improve onto of sound proofing the interior, for sure. I can hear it.

The pilot 4S and even 5S's are very loud tires, even in a modern day Mercedes. Listen to the tire noise inside the cabin of this Mercedes,



Then listen to the tire noise in my videos' recorded from an iPhone which is picking up all sounds.

Mission Accomplished!

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