Where does extra sound insulation make the most difference?

[GriffX]

anyone doing the inside of the trunk decklid? the holes are really small and there is not much room between the skeleton and the panel.

Because of this I decided not to do it. I don't think it can be done in an optical pleasant way. And, there is often condensed water inside, with alubutyl or high density plastic you can get water pockets.

 

[DieHarder]

Because of this I decided not to do it. I don't think it can be done in an optical pleasant way. And, there is often condensed water inside, with alubutyl or high density plastic you can get water pockets.

There are rug kits for the rear trunk and I did do part of the inside lid with a rubber product. Didn't seal the whole thing. Actually, quieted sound in the trunk area quite a bit without any ill effects or holding water that I can find.

 

[Jwood562]

I plan on getting a rug kit for my trunk also, love the clean look

 

[GriffX]

Of cause it depends where you living, the trunk lid has 3 water release holes at the bottom. In my area all my cars got rust in the trunk lid after some years. Mercedes has lots of problems with rust in that area.

 

[DieHarder]

I live in the northern climbs and did have a bit of rust on the driver's side. Cleaned it out and fiberglassed that area and no issues since (5 years now). Regarding trunk kits there are several liners out there to choose from. Most look similar to this in design and quality. If I remember it ran around ~$100 or so....? All I added was some 10mm self-stick foam under it; and it does an impressive job of knocking down noise. Now, I have to get to the headliner some day but work and life always seem to have a laundry list of things that must be done first.

 

[Jwood562]

I live in the northern climbs and did have a bit of rust on the driver's side. Cleaned it out and fiberglassed that area and no issues since (5 years now). Regarding trunk kits there are several liners out there to choose from. Most look similar to this in design and quality. If I remember it ran around ~$100 or so....? All I added was some 10mm self-stick foam under it; and it does an impressive job of knocking down noise. Now, I have to get to the headliner some day but work and life always seem to have a laundry list of things that must be done first.

View attachment 87124 View attachment 87125

that’s exactly the liner I’m looking for. I have one on my eBay watchlist, but if you can remember where you bought this exact one let me know.

rust and water are not an issue for me. SoCal garage kept mustang

 

[JC SSP]

CJ Pony has one...

QuietRide Solutions Mustang Under Trunk Cover Kit AcoustiHood Coupe 2005-2009 (cjponyparts.com)

 

[DieHarder]

This: https://www.ebay.com/itm/255088797453

Price is a bit higher than it used to be but so is everything. Good product if you want it.

 

[GriffX]

Unpleasant side effect. I have a drone/vibration between 65 to 69 MPH, I guess it is from the driveshaft.
Now, because the car is quieter, the drone gets annoying. So, work never ends ...

 

[pass1over]

I covered my entire inside of my trunk area with butyl, including the lid. Zero rust issue and I've never had any water in there. Before or after using the butyl.

 

[GriffX]

I want to buy insulation for the front floor. How much thickness you guys think it is possible to add? 5 mm, 10 mm?
Found a seller of Mercedes type insulation which is removable.

 

[ghunt81]

I put that 10 mm thick foam all over the front floor and tunnel, you can fit it under the carpet if you pull out the factory fiber mat stuff.

 

[GriffX]

Update: I removed the rear quarter panel inner liners to remove the parcel shelf cover for insulation and noticed that several alubutyl sheets came partly loose. Some at the edges, some in the middle. Looks like the ones who are exposed to heat are more affected. (which would make sense due to the different expansion of alu vs. iron). I cleaned the surface with alcohol before. One 4x6 sheet I could take off almost completely. Now, I'm a bit concerned for the parts under the roof.
Haven't done the doors, I guess I will buy the rubber sheets dedicated for automotive application first.

 

[ghunt81]

That surprises me, because that tar stuff is sticky as hell.

 

[GriffX]

FYI, I placed the butyl stripes according to this guide and added 1 cm acoustic dampening material (self sticking) for cars at the inside of the liners or at the roof itself. Noise level dropped like 15 mph slower driving. I did not do the doors and the floor, yet, only trunk, quarter panel, roof, parcel shelf.

https://www.quietride.com/web/viewe...nstructions/AS/Ford/Mustang/MUST 1014-CAK.pdf

 

[GriffX]

Now after several weeks of the new driving experience, I wish I would have done this right after I got the car. It is so much more enjoyable to drive, I do not miss the tire and axle noise at all
I think the combination of alubutyl stripes with damping material was a good choice.

 

[GriffX]

The parcel shelf, again 1 cm thick insulation, noticeable effect combined with alubutyl stripes.

 

[GlassTop09]

Been reading thru this thread w\ interest sooo........

I have some Dynamat Xtreme sound deadening sheets along w\ the sheet roller tool coming to apply in my Stang.

I'm only looking to use this on unibody area under the rear seat\trunk (where the rear axle UCA\LCAs & PHB attach to the unibody as well as both Pypes M80 mufflers & Pypes Super Bomb 4" x 14" resonator tips reside) as the rear parcel shelf & both doors have already been done when I had my Kenwood audio system installed some 5 yrs ago & since I had the Kooks Hi Flow Race cats replaced w\ these MF #5461336 CARB-cert cats, this remedied the excessive exhaust droning (was the high volume of sound frequencies emitted from the Kooks cats metal substrates reverb off exhaust gas pulses flowing thru them radiating into the unibody floor causing the unibody floor to reverb into cabin......the MF cats use OEM-rated ceramic substrate materials which do not reverb off exhaust gas pulses thus no more excess sound frequency transfer into the unibody floor thus no more unibody floor reverb......I have 2 exhaust hangers installed on Kooks midpipe attaching to trans crossmember thus a NVH frequency transfer point). Since I have a glass roof there's essentially nothing up there (not enough sheet metal area) to set up reverb in the roof area. I also have a Blowfish Racing Remote Shifter bracket installed so this removes the shifter itself being a point of NVH transfer into unibody as well (OEM S197 manual remote shifter design attaches to unibody & transmission housing thus provides another NVH transfer point into unibody thru driveline......especially if the shifter mounting bushings are stiffened vs OEM) so the only other viable area left to treat is under the rear seat\trunk area.

My goal is to reduce as much road noise entry thru rear of car as possible & since there is a lot of unibody sheet metal exposed in trunk\under rear seat w\o any meaningful sound deadening material installed I figured I'd give this a shot as I plan to put my Stang on more long road trips..........from reading up on y'all's experiences from doing this to your steeds, I decided to jump in as well.

Appreciate all the info posted!

 

[GriffX]

I highly recommend to dampen the rear quarter trim panel from the inside as much as possible in addition to any dynamat shield. This area is one of the main for tire noise. And the plastic panel above the SJB can be dampened, too.

 

[GlassTop09]

I highly recommend to dampen the rear quarter trim panel from the inside as much as possible in addition to any dynamat shield. This area is one of the main for tire noise. And the plastic panel above the SJB can be dampened, too.

Will check into this area as well while I'm in there............thanks!