GT3 DIY sound insulation
08-17-2021, 11:45 PM
#61
Rennlist Member
So it begins…
The following users liked this post:
heshalosny (02-09-2022)
08-19-2021, 11:32 AM
#62
Rennlist Member
So I didn't go crazy. Focused on panels facing the driver that could bounce off the rear window. The rear fenders were covered inside and out under the fender liners. Finally, one layer of Noico foam applied on top- very tacky and difficult to put into tight spaces! Small pieces are easier but still a pain. Initial impressions were... not so much reduction as expected. Need a little more time to evaluate on all roads. Maybe I should cover more of the horizontal area under the rear seat area and under the front seat??? or do the doors?? I purposefully didn't cover the area of the rear seating where there are cross braces. FYI I elected not to remove the rear side panels after struggling with the first one. It didn't want to come out, one latch was not releasing and then was a bitch to line up all the latches to get it back in.
Not sure if linked here before, but the Cantrell bar install guide is very helpful for how to remove interior pieces: https://cantrellmotorsport.com/wp-co...-WITH-PICS.pdf
Last edited by montoya; 08-19-2021 at 11:34 AM.
The following 3 users liked this post by montoya:
08-21-2021, 05:31 PM
#63
Rennlist Member
Thread Starter
So I didn't go crazy. Focused on panels facing the driver that could bounce off the rear window. The rear fenders were covered inside and out under the fender liners. Finally, one layer of Noico foam applied on top- very tacky and difficult to put into tight spaces! Small pieces are easier but still a pain. Initial impressions were... not so much reduction as expected. Need a little more time to evaluate on all roads. Maybe I should cover more of the horizontal area under the rear seat area and under the front seat??? or do the doors?? I purposefully didn't cover the area of the rear seating where there are cross braces. FYI I elected not to remove the rear side panels after struggling with the first one. It didn't want to come out, one latch was not releasing and then was a bitch to line up all the latches to get it back in.
Not sure if linked here before, but the Cantrell bar install guide is very helpful for how to remove interior pieces: https://cantrellmotorsport.com/wp-co...-WITH-PICS.pdf
1-You need to put more sound deadening in the rear wheel wells.. That is by far where you get the most road noise reduction, as regular (non GT) 911s have a large cover completely covering both rear wheel wells for sound control. I covered those rear wheel wells completely with sound insulation, while I see gaps in the coverage of those areas in your photo above.
2- I highly recommend adding sound deadening to the doors. The doors and the rear wheel wells provide the biggest reduction of road noise.
Last edited by Drifting; 08-21-2021 at 07:16 PM.
08-21-2021, 07:25 PM
#64
Rennlist Member
Two recommendations.
1-You need to put more sound deadening in the rear wheel wells.. That is by far where you get the most road noise reduction, as regular (non GT) 911s have a large cover completely covering both rear wheel wells for sound control. I covered those rear wheel wells completely with sound insulation, while I see gaps in the coverage of those areas in your photo above.
2- I highly recommend adding sound deadening to the doors. The doors and the rear wheel wells provide the biggest reduction of road noise.
1-You need to put more sound deadening in the rear wheel wells.. That is by far where you get the most road noise reduction, as regular (non GT) 911s have a large cover completely covering both rear wheel wells for sound control. I covered those rear wheel wells completely with sound insulation, while I see gaps in the coverage of those areas in your photo above.
2- I highly recommend adding sound deadening to the doors. The doors and the rear wheel wells provide the biggest reduction of road noise.
08-21-2021, 07:37 PM
#65
Former Vendor
Copying and pasting this from another thread I posted in. Just want to help clear up some information about sound treatment in vehicles
So a few things to note that were brought up in this topic that I figured i'd help clear up for current/future readers
For starters, please do yourself a favor and do not use cheap amazon sound deadening products. You will be cleaning melted butyl of your expensive car in the future.
Second, please don't bother with trying to absorb outside noise with acoustic foam. You're fighting an uphill battle in this environment.
I'd also like to explain the different types of sound deadening, as there is a TON of misinformation out on the web about this stuff
1) Constrained Layer Dampers, aka CLD. These types of products, typically referred to as "dynamat" are the most popular types of sound treatment in the aftermarket automotive world. They are meant to reduce resonance of panels via using their 2-layer composition. The butyl rubber layer uses its viscoelastic properties in reference to the aluminum constraining layer to create sheer resistance, which converts mechanical energy into low-level thermal energy. They do NOT work by adding mass. Adding mass only lowers the resonant frequency of the panel you are adhering it to. CLD does a little bit of that (since it does add weight), but mostly lowers the Q of the resonance peak. These typically SEEM to lower road/tire/exhaust noise, but they actually don't help much for these directly. What they usually fix is just the resonance of panels that is caused by those sounds. How much these will lower the overall noise floor of a given car entirely depends on the car. Also, the range of level of quality in these products is absolutely absurd. Do not cheap out. Do it once, do it right.
2) Decouplers, typically Closed Cell Foams, aka CCF. These products, usually called CCF (Dynaliner being one of these products) are the next most popular sound treatment product in the aftermarket automotive world. The purpose of these products is to decouple two hard panels from resonating against each other and providing a cushion so they don't create annoying buzzes and rattles. They are also used to decouple and provide an air gap for noise barriers (the next type of product) to allow them to be as effective as possible. What they do not do is absorb any meaningful amounts of noise, and they definitely do not block any outside noise. That brings us to the next product..
3) Noise Barriers, typically being mass-loaded vinyl, aka MLV. Noise barriers are used to BLOCK outside noise. If you want to get rid of tire noise, exhaust drone, etc.. this is it. The problem with noise barriers is that you cannot just spot treat with them. It's pretty much all or nothing. A lot of people are now starting to use encapsulated lead style products since they are much thinner, are moldable, and are even more effective and easier to work with than their MLV counterparts.
If you want to learn more about these and how they work, here ya go.
https://resonixsoundsolutions.com/re...e-information/
For starters, please do yourself a favor and do not use cheap amazon sound deadening products. You will be cleaning melted butyl of your expensive car in the future.
Second, please don't bother with trying to absorb outside noise with acoustic foam. You're fighting an uphill battle in this environment.
I'd also like to explain the different types of sound deadening, as there is a TON of misinformation out on the web about this stuff
1) Constrained Layer Dampers, aka CLD. These types of products, typically referred to as "dynamat" are the most popular types of sound treatment in the aftermarket automotive world. They are meant to reduce resonance of panels via using their 2-layer composition. The butyl rubber layer uses its viscoelastic properties in reference to the aluminum constraining layer to create sheer resistance, which converts mechanical energy into low-level thermal energy. They do NOT work by adding mass. Adding mass only lowers the resonant frequency of the panel you are adhering it to. CLD does a little bit of that (since it does add weight), but mostly lowers the Q of the resonance peak. These typically SEEM to lower road/tire/exhaust noise, but they actually don't help much for these directly. What they usually fix is just the resonance of panels that is caused by those sounds. How much these will lower the overall noise floor of a given car entirely depends on the car. Also, the range of level of quality in these products is absolutely absurd. Do not cheap out. Do it once, do it right.
2) Decouplers, typically Closed Cell Foams, aka CCF. These products, usually called CCF (Dynaliner being one of these products) are the next most popular sound treatment product in the aftermarket automotive world. The purpose of these products is to decouple two hard panels from resonating against each other and providing a cushion so they don't create annoying buzzes and rattles. They are also used to decouple and provide an air gap for noise barriers (the next type of product) to allow them to be as effective as possible. What they do not do is absorb any meaningful amounts of noise, and they definitely do not block any outside noise. That brings us to the next product..
3) Noise Barriers, typically being mass-loaded vinyl, aka MLV. Noise barriers are used to BLOCK outside noise. If you want to get rid of tire noise, exhaust drone, etc.. this is it. The problem with noise barriers is that you cannot just spot treat with them. It's pretty much all or nothing. A lot of people are now starting to use encapsulated lead style products since they are much thinner, are moldable, and are even more effective and easier to work with than their MLV counterparts.
If you want to learn more about these and how they work, here ya go.
https://resonixsoundsolutions.com/re...e-information/
The following 3 users liked this post by ResoNix Sound Solutions:
08-21-2021, 10:17 PM
#66
Rennlist Member
Thread Starter
Thanks for the advice! I really couldn’t remove the drivers side panel at all. Really struggled it seemed as though one latch was stuck. I’ll try again, because without removing the side panel you can’t access the rear fender completely. And I will be doing the doors for sure. Happy to say there is no reduction in sweet engine notes!
Not necessary to remove the rear side panels, IMHO. But I would still recommend more coverage of insulation over the area of the rear wheel wells that you can see without removing the rear side panels.
The following users liked this post:
montoya (08-23-2021)
05-17-2022, 03:04 PM
#67
Rennlist Member
Found this thread & originally came to comment “why reduce the sound in a GT3?”……. after reading it, this will now be one of my winter mod projects. Total 180’ !!!
For only 11 pounds extra weight, it makes total sense to cut down some of the extra road white noise, while keeping the glorious 4.0L motor sound.
The biggest factor that changed my mind is that my 4 year old absolutely loves riding in the GT3 with me (never long rides, or wot). Since I’ve never had a loud enough car to worry about hearing damage, this was an unknown concern to me. For my little guy, I’m willing to try this to protect him.
Threads like this are why I love Rennlist.Thanks guys.
I’ll probably post back with questions and asking for advice once winter sets in & the car is put into storage.
For only 11 pounds extra weight, it makes total sense to cut down some of the extra road white noise, while keeping the glorious 4.0L motor sound.
The biggest factor that changed my mind is that my 4 year old absolutely loves riding in the GT3 with me (never long rides, or wot). Since I’ve never had a loud enough car to worry about hearing damage, this was an unknown concern to me. For my little guy, I’m willing to try this to protect him.
Threads like this are why I love Rennlist.Thanks guys.
I’ll probably post back with questions and asking for advice once winter sets in & the car is put into storage.
02-20-2023, 08:15 PM
#68
Alright
So it looks like no one in this thread has actually taken DB readings of inside the car before and after applying the sound deadening.
I have Tinnitus and at full throttle rip, the car registered a max DB of 95 at a certain resonance and ended redline at 92.9DB. I believe anything over 90 will cause my right ear to get louder without protection and thus plan to get the interior of the car to around the 90db range maximum.
I plan to do a few stages of modifications.
1. I'll do a DB test fully in stock form, in automatic mode, I'll record on a stretch of highway and get the Max and AVG decibel rating.
2. First I plan to do sound deadening on the doors of the car. I will redrive the stretch of road, and get the average and max reading.
3. I'll do the full rear carpet area as OP has done and get the decibel ratings over the same stretch of road.
I plan to do this over the course of the next 1-2 months. Currently it is scheduled to snow and won't be able to get an initial decibel reading until it has cleared up.
Materials I will be using are the Noico from Amazon. I'll be using thicker material than what OP used. It'll be 2mm Butyl sound deadener followed by Noico Red 8mm PE foam. This may change depending on how much the road noise is reduced following the door installation. I may opt for thinner PE if it's deadening is too much.
Will keep you all posted.
So it looks like no one in this thread has actually taken DB readings of inside the car before and after applying the sound deadening.
I have Tinnitus and at full throttle rip, the car registered a max DB of 95 at a certain resonance and ended redline at 92.9DB. I believe anything over 90 will cause my right ear to get louder without protection and thus plan to get the interior of the car to around the 90db range maximum.
I plan to do a few stages of modifications.
1. I'll do a DB test fully in stock form, in automatic mode, I'll record on a stretch of highway and get the Max and AVG decibel rating.
2. First I plan to do sound deadening on the doors of the car. I will redrive the stretch of road, and get the average and max reading.
3. I'll do the full rear carpet area as OP has done and get the decibel ratings over the same stretch of road.
I plan to do this over the course of the next 1-2 months. Currently it is scheduled to snow and won't be able to get an initial decibel reading until it has cleared up.
Materials I will be using are the Noico from Amazon. I'll be using thicker material than what OP used. It'll be 2mm Butyl sound deadener followed by Noico Red 8mm PE foam. This may change depending on how much the road noise is reduced following the door installation. I may opt for thinner PE if it's deadening is too much.
Will keep you all posted.
Last edited by lt1camaro; 02-20-2023 at 08:17 PM.
The following 5 users liked this post by lt1camaro:
brontosaurus (05-01-2023),
montoya (02-20-2023),
Overdraft (12-02-2023),
Proturbo (02-24-2023),
Shooter992C2S (05-22-2023)
09-10-2023, 04:46 PM
#69
I’m going to tackle this insulation project over the winter this year. I plan to do the doors, fender liners and under the rear carpet. Has anyone used the Resonix CLD squares. It looks like it has nice sound deadening properties. Here is a link:
https://resonixsoundsolutions.com/sh...und-deadening/
https://resonixsoundsolutions.com/sh...und-deadening/
09-10-2023, 08:55 PM
#70
Rennlist Member
Thread Starter
I’ll say it one more time. I highly recommend that you add sound insulation to the doors and the interior rear wheel wells, and then stop and go for a couple drives to decide how well you like the sound before doing the rest.
Adding sound insulation to the doors and rear window wells is a no brainer as it only reduces road/tire noise and not engine noise. I definitely recommend doing both which really cuts down on road/tire noise, with minimal weight.
Adding sound insulation to the rest of the rear deck is more debatable as it also reduces a fair amount of “good” engine noise while further reducing undesirable road noise).
Adding sound insulation to the doors and rear window wells is a no brainer as it only reduces road/tire noise and not engine noise. I definitely recommend doing both which really cuts down on road/tire noise, with minimal weight.
Adding sound insulation to the rest of the rear deck is more debatable as it also reduces a fair amount of “good” engine noise while further reducing undesirable road noise).
The following users liked this post:
Dreamer99 (09-11-2023)
09-11-2023, 10:33 AM
#71
Rennlist Member
I’m going to tackle this insulation project over the winter this year. I plan to do the doors, fender liners and under the rear carpet. Has anyone used the Resonix CLD squares. It looks like it has nice sound deadening properties. Here is a link:
https://resonixsoundsolutions.com/sh...und-deadening/
https://resonixsoundsolutions.com/sh...und-deadening/
Also did the doors, mainly because I've upgraded my stereo pretty heavily and you get serious mid-bass improvement sealing up the door.
09-12-2023, 11:04 AM
#72
I downloaded a free sound meter app and have a couple reference levels as a baseline. I held my phone between the seats at head level for the reading. I have new Cup2 tires on the car.
3000rpm (120 kmh) on a smooth highway is 74 dB
Flat out on same highway through second, third and into fourth gear the peak reading was 102 dB.
I plan on taking the fender liners off to insulate the backside of them plus the doors as a minimum.
3000rpm (120 kmh) on a smooth highway is 74 dB
Flat out on same highway through second, third and into fourth gear the peak reading was 102 dB.
I plan on taking the fender liners off to insulate the backside of them plus the doors as a minimum.
Last edited by Dreamer99; 09-12-2023 at 11:08 AM.
10-04-2023, 09:30 PM
#73
10-05-2023, 09:35 AM
#75
I plan on doing an insulation project on my GT3 this winter. I was thinking that the wheel well insulation could be covered with a coat of Flex Seal for protection. Thoughts?