flynhi

I have completed sound deadening on the bulkhead behind the seats and rear deck areas. I'd like to do the same with footwells and under the seats to deal with noise on the chip eal paving overlay on Texas roads.

Has anyone done a How To on this. Can't find one with Search.

Tks

Crossed Flags Fan

I didn't take pix but here's what you'll need to do this project. Figure about 3.5 to 4 hours - TAKE YOUR TIME!!!!. Read thru the entire post before you start.
Obviously if anyone else has a better or easier solution, don't flame, just post your experience...
I had the time (and built up the courage) to do the front this week. I did the rear from the back of the hatch area up to the bulk head/right behind the front seats a while ago. (I used Fat Mat Extreme for the rear. For the front I used Fat Mat Extreme and covered that with Frost King Duct Insulation. I used one roll of Frost King).
To install you'll need:
a-Plastic trim remover
b-Socket wrench and extension
c-10mm socket
d-15mm socket (deep preferred, but not required)
e-2 Heavy duty blankets

As with any trim removal make sure you get a plastic trim removal tool as mentioned in other threads regarding trim removal - Harbor Freight has them for practically nothing. DON'T use a screw driver!

TO REMOVE THE SEATS:
Remove the targa roof/open the convertible roof.
First - carefully remove the plastic trim at the door sill and the trim that attaches to it up to the base of the windshield. You should be able to just pull it up and away from the door sill. Put aside.
Second - remove the covers found on the floor at the base of the front of the seats. Push/pull them forward, DON'T pull up to release them. Covers are only at the front of the seats. Using the 15mm socket remove the nuts. Now remove the rear nuts.
Third- position and raise the seat base so you can disconnect the seat's electrical connection under the front of the seat frame. You'll see it right away. The connection harness is held to the seat frame in two places. Using either the trim removal tool or your hands, push the connector down from the seat frame.
Fourth - Separate the connector from the wiring harness. There is a "lock" on the bottom part of the connector that you need to push and swing it down to release the connector. Next, pull the connector apart. (Note - you will no longer be able to move the seats once the connector is apart, so make sure the seat(s) positioned where you will be able to remove them from the car.)
Fifth - Remove outside seat belt. Using the trim remover remove plastic cover at the metal clip. Remove the 10 mm bolt and manuver the two pieces from each other.
Sixth -Seat Removal - IT IS AWKWARD TO LIFT THEM OUT. Before you remove it, place a heavy duty blanket (or old piece of carpet) down where you will be putting aside the seat. The seat may roll to the side so having the blanket/old piece of carpet, etc. will help prevent the seat side, plastic, leather from scratches.
Put the second heavy duty blanket over the door sill, hold it in place with painters tape. This will help prevent scratching the door sill when you remove and replace the seat. The seat frame that attaches to the floor sticks out further than you think...ask me how I know.
Carefully remove and place the seat out of the car. Again, its somewhat heavy and awkward.

Carpet - I did not remove the carpet, only lifted and "rolled" it aside and back. There may be a way to remove it, but my goal was to do as little "removal" as possible.
First - Remove the gas pedal. This is relatively easy. You'll note there is a rubber piece/cover that is on the left side of the gas pedal "stand'. It's just a "pull straight out" manuver, it's soft rubber - the easiest part of the project. Put it aside.
You'll note a 10 mm bolt holding the pedal to the floor - remove it. Pull the pedal from the stand. Put aside.
Second - There is an electrical connector for the wiring to the pedal. Carefully release the connector from the wiring harness. Put bolt and pedal aside. I found it difficult to pull it apart, but eventually it did.
Third - pull the "dead pedal" from the floor. It is not bolted or screwed in. Relatively easy to pull it up. It snaps in, pulls out.
Fourth - This is where it gets tricky...carefully pull/fold back the carpeting, starting where the dead pedal was, then the gas pedal side. You'll need to pull it out from the places where it tucks under some of the trim.
You'll note that there is a frame where the dead pedal attached to. Remove the two bolts 10mm. ALSO there is a plastic push attachment on the left side of the frame. Use your trim removal tool to release it. Put the frame aside. Note that there is wiring that is being protected by the dead pedal frame.
NOTE - you can try to move/position the manual door openers on the floor to make it easier to lift the carpeting. There is a pop off cover over each of the two the torx screws. I was only able to remove one of the torx screws on each side, so I left them in place. If you are able to remove or re-position them it may be helpful to do so.
NOTE - I CAREFULLY folded the carpet back as far as possible and then lifted it where the seat(s) were. I didn't remove any other trim or the console. I was able to put down Fat Mat Extreme and then the Frost King by manuvering hem under the carpeting where the seat was. It was tricky, but take your time, it's do-able.
Be careful not to rip or tear the carpet when you lift and re-position it.

Just reverse the process above to put everything back together. Be careful not to stress the wiring that you are covering and I suggest you use a paper/cardboard template to figure the sizes of the insulation rather than a exacto blade or cutting/fitting the actual insulation to size on the floor. If you nick or cut a wire you'll go crazy trying to figure out where it is.

PASSENGER SIDE - same procedure except obviously you don't have the gas/dead pedal. NOTE - there is a two level "floor" on the passenger side. Most of the wiring goes under the top level "floor". I did not remove the top level floor to put in the insulation/sound proofing. I put them over it. I suppose it would have made it quieter but I didn't want to cover all the wiring that was there. Your call.

I did notice a difference in the quietness of the car. Unfortunately I didn't take a reading using a sound level meter. I didn't notice as much of a difference in extremely rough concrete pavement, but it was quieter. I'm not sure if it was the "placebo" effect or not, but the sound system did sound much richer and better base.

Let me know if you have any questions......and good luck.

flynhi

Thanks very much - very helpful!
What's a guess as to the weight of a seat?
Did the thickness of the FatMat and Frost King cause much of a problem reinstalling carpet?
W

RussM05

I read somewhere the seats weigh 59 lbs. each.

flynhi

Thanks - I use the forklift....

Crossed Flags Fan

I'd say Russ is right~60 lbs. That and manuvering it around is a pain.
No isssue with the thickness of both.

flynhi

Thanks el mucho!

Vetteman Jack

Thanks for the great write-up.

flynhi

I just finished this install and offer this summary.

My C7 Coupe has 19" and 20" Michelin Pilot Super Sport ZPs which are extremely noisy on the chip seal overlay that is used here in Austin to extend the life of asphalt paving.

So I overdid it with two layers of Damplifier mat and a layer of 3/8" closed cell foam.

The install went as described above on the passenger side. The carpet came out with some effort and the installation of Damplifier and foam was slow but straightforward. I used 3M spray upholstery glue to hold the foam in place. Carpet and seat reinstall was made difficult by the thickness of the three layers. Things get particularly tight between the passenger side of the tunnel and the side rail. So, my advise is to not install foam on the tunnel and or side rail.

The install on the driver's side was more difficult. For some reason, I could not remove the gas pedal. Perhaps my Jan '15 assembly date cars had a different method of installation than the OP. This meant that I could not remove the carpet. Which meant that the install of Damplifier and foam was VERY slow. The space between the tunnel and side rail on the driver's side is narrower than the Passenger side so, again, do not install foam there.

Primarily due to cutting and fitting three pieces for every surface to be covered, I spent almost 11 hours on the footwells and underseat areas. The same was true for the rear deck. That area took about 5 hours.

The difference in sound levels is worth the time and sore knees. On asphalt roads, I hear almost no sound from the tires and on chip seal, the sound is audible but now does not interfere with conversation.

Mission Accomplished......

Rooster OG

Good job! I have all the materials sitting here mocking me, but I haven't gotten the nerve up to start. I can only imagine it must be a big improvement, doing the back helped a ton.

DaveFerrari458

With so many threads about sound deadening, I wonder why GM just doesn't offer this as an option straight from the factory?

Perhaps, it's a good "Ask Tadge" question?

flynhi

Suggestion:
You will be spending a lot of time on your knees. So get 4-6" of foam wrapped in a towel to kneel on. I stacked two foam pillows and wrapped them in thick towels to save my kneecaps....

flynhi

Agree. I should come with a sound system upgrade.

To their credit, the white foam on the back of the carpet is pretty good - much better than on my C5.

Clearly, GM will not spend 11 hours to piece in materials like I did but they could spray on a couple of layers of a viscous material like the one sold by Second Skin to do what Dynamat, FatMat, Damplifier do.

waunavet

This is an absolute necessity. I used a section of anti-fatigue floor matting. Lays nice and flat and easily moved.

waunavet

I've done a C5, 6 and 7. It's really not that hard. The 2015 offered a few more challenges because of the wiring on the floor. I cut dozens of pieces to fit around everything and covered the complete floor and transmission hump. Spent at least 2.5 hours on each side just installing the insulation. Worth every minute and a sore back for 2 days. The results are amazing. PM me if you'd like some additional information. Glad to help.