Soundproofing a Town Car

[HighwayStar]

Hello all, long time lurker, first time poster here. I am currently hunting for a Town Car and have big plans for what I want to do with it when I find it.
One of my planned upgrades is some soundproofing. Yes, I am aware a Town Car is already quiet, but I want to get it as quiet as I reasonably can (If for no better reason than to have an answer to those snobbish Tesla drivers and their glorified golf carts).
Has anyone had any experience doing this? Which products did you use, where did you put it, etc.
Also, if you have not done soundproofing, but have had to disassemble the car for other work, can you give me any insights to what soundproofing is already there? Is the metal under the floor, doors, etc. bare?
Hope this starts an informative and entertaining thread!

 

[AgentOrange]

It's a little far off from what you're doing here, but I covered the floor of my 1977 F-150 in Dynamat and under the dash in Dynapad foam. That noticeably cut down on road roar. Not so much the engine sound, but then long tube headers and a Flowmaster on a 460 just ain't gonna be quiet. Did it in the roof and doors. Gave them a solid feel and totally canceled out any tin can sound when I closed the doors. I'd like to do some further sound deadening in my 88 TC like what you're going to do in yours. I'm with you on that! Just to see how quiet we can get them. Taking something great and making it better is always a fun challenge. I'm also with you on those glorified golf carts. HaHa!

 

[HighwayStar]

It's a little far off from what you're doing here, but I covered the floor of my 1977 F-150 in Dynamat and under the dash in Dynapad foam. That noticeably cut down on road roar. Not so much the engine sound, but then long tube headers and a Flowmaster on a 460 just ain't gonna be quiet. Did it in the roof and doors. Gave them a solid feel and totally canceled out any tin can sound when I closed the doors. I'd like to do some further sound deadening in my 88 TC like what you're going to do in yours. I'm with you on that! Just to see how quiet we can get them. Taking something great and making it better is always a fun challenge. I'm also with you on those glorified golf carts. HaHa!

Thanks for the input. Its good to get a "it really works" statement, since you see all kinds of claims about soundproofing and what kind of results you can expect. Did you notice any thermal benefits in terms of insulation?

 

[dave42]

A big reason a TC is quiet is because they have hundreds of pounds of insulation already in it. If you drive one, you might decide it is quiet enough. I have to roll my driver window down to hear the rattle/squeek that is starting up in my front suspension. The thing that makes the most noise on the highway is the wind buffeting the big mirrors. That sound is coming through the windows and more deadening won't help it.

Just turn up the Deep Purple in your stereo and you won't hear anything.

______________________________

 

[HighwayStar]

A big reason a TC is quiet is because they have hundreds of pounds of insulation already in it. If you drive one, you might decide it is quiet enough. I have to roll my driver window down to hear the rattle/squeek that is starting up in my front suspension. The thing that makes the most noise on the highway is the wind buffeting the big mirrors. That sound is coming through the windows and more deadening won't help it.

Just turn up the Deep Purple in your stereo and you won't hear anything.

Ahh, now that is the cheating solution, to turn up the stereo!
But what kind of insulation does it have? Is it bonded to the metal or loose? If it is loose I can put Dynamat under it or something like that.
Regardless of how quiet it is, I want to make it as quiet as it can be, so perhaps the question becomes whether it can accept any more sound insulation. I am shooting for quieter than a Tesla.

 

[AgentOrange]

Thanks for the input. Its good to get a "it really works" statement, since you see all kinds of claims about soundproofing and what kind of results you can expect. Did you notice any thermal benefits in terms of insulation?

It's hard to say on the thermal side of things. Maybe I gained a little insulation? My pickup doesn't have AC (yet) and with a 460 custom built to tow under the hood, the heat tends to get everywhere. I'd like to say that putting it in the roof made a difference as far as heat radiating down, but maybe I just think it does.

 

[CuttingToolGuy]

HighwayStar,
Welcome.

Do you have a generation of TC you are liking more than another? An 80's vs a 90's vs a 2000's will have different starting points.

I think there are at least 3 types of "noise" you need to think about: engine, friction & wind turbulence. You should probably pick 1 to focus on at a time. Divide and conquer so to speak.

Engine: a narrower muffler system, sound absorbing mat under the hood and covering external firewall and inner fenders. The last generation came with a plastic engine shield. It was there for sound reduction. First and second generations could use a shield too. Also a larger air intake, baffled and opening as far away from the passengers helps. Header thermal wrap around the exhaust will help too. Power steering pump and out of adjustment steering will make noise too.

Friction: Ever heard a 4x4 pickup with knobby mud tires pass you on the highway? Compare that to a trailer tire. Trailer tire has a simple groove vs the many irregular notches a knobby tire has. The notches contribute greatly to road noise. When was the rear end oil last changed? Worn out oil won't cling to the gears as well and allow more friction & noise. Ball joints, tie rod ends and even the rubber seats the springs ride in can all add to the noise of a used car.

Wind Turbulence: Again, depending on which generation you like, anything that generates turbulence will generate noise. Abrupt changes in form, sharp edges, antennas, chrome trim, wheel patterns all make noise the faster you go. Remember, luxury cars of yore often came with skirts on the rear wheels. The laminar flow is much quieter than the rolling air made by tire & rim. Even a Prius has skirts. Seal off any gaps you cN such as hood to fascia providing it doesn't cause cooling problems or look ugly. Look at the bottom of a newer Tesla or Jaguar or Audi, etc. they have panels down there to provide more laminar flow. Compare that to any TC and you can see where a lot of turbulence comes from. A diffuser on the back could help with MPG and noise at the same time. Paneling up the bottom of a TC is going to take some custom work. Modern pickups have a similar underside to a TC and they are using air dams and splitters to force the air out from under the trucks. That would probably be the easier rout to go. Even a spoiler that puts the turbulence zone further away from the passengers can help make things quieter.

The guys designing the Teslas are fighting to reduce friction so the car can go further on a given battery charge. Friction creates noise. So the moving quietness is a happy byproduct of the effort to increase range.

 

[HighwayStar]

HighwayStar,
Welcome.

Do you have a generation of TC you are liking more than another? An 80's vs a 90's vs a 2000's will have different starting points.

I think there are at least 3 types of "noise" you need to think about: engine, friction & wind turbulence. You should probably pick 1 to focus on at a time. Divide and conquer so to speak.

Engine: a narrower muffler system, sound absorbing mat under the hood and covering external firewall and inner fenders. The last generation came with a plastic engine shield. It was there for sound reduction. First and second generations could use a shield too. Also a larger air intake, baffled and opening as far away from the passengers helps. Header thermal wrap around the exhaust will help too. Power steering pump and out of adjustment steering will make noise too.

Friction: Ever heard a 4x4 pickup with knobby mud tires pass you on the highway? Compare that to a trailer tire. Trailer tire has a simple groove vs the many irregular notches a knobby tire has. The notches contribute greatly to road noise. When was the rear end oil last changed? Worn out oil won't cling to the gears as well and allow more friction & noise. Ball joints, tie rod ends and even the rubber seats the springs ride in can all add to the noise of a used car.

Wind Turbulence: Again, depending on which generation you like, anything that generates turbulence will generate noise. Abrupt changes in form, sharp edges, antennas, chrome trim, wheel patterns all make noise the faster you go. Remember, luxury cars of yore often came with skirts on the rear wheels. The laminar flow is much quieter than the rolling air made by tire & rim. Even a Prius has skirts. Seal off any gaps you cN such as hood to fascia providing it doesn't cause cooling problems or look ugly. Look at the bottom of a newer Tesla or Jaguar or Audi, etc. they have panels down there to provide more laminar flow. Compare that to any TC and you can see where a lot of turbulence comes from. A diffuser on the back could help with MPG and noise at the same time. Paneling up the bottom of a TC is going to take some custom work. Modern pickups have a similar underside to a TC and they are using air dams and splitters to force the air out from under the trucks. That would probably be the easier rout to go. Even a spoiler that puts the turbulence zone further away from the passengers can help make things quieter.

The guys designing the Teslas are fighting to reduce friction so the car can go further on a given battery charge. Friction creates noise. So the moving quietness is a happy byproduct of the effort to increase range.

Lots of good info and thoughts here, thank you very much!

I am mostly interested in the 2003-2011 version of the Town Car.
I had not thought of most of the points you bring up, and I will definitely include them in the master plan.
I had considered the tires issue, and looked at some of the quieter rated tires available.
I am still thinking that sound insulation would be a good step, since it will act against several cluprits at once and maximise the reduction, but you have definitely broadened my thinking on the issue.

______________________________

 

[Brian J. Patterson]

Hello all, long time lurker, first time poster here. I am currently hunting for a Town Car and have big plans for what I want to do with it when I find it.
One of my planned upgrades is some soundproofing. Yes, I am aware a Town Car is already quiet, but I want to get it as quiet as I reasonably can (If for no better reason than to have an answer to those snobbish Tesla drivers and their glorified golf carts).
Has anyone had any experience doing this? Which products did you use, where did you put it, etc.
Also, if you have not done soundproofing, but have had to disassemble the car for other work, can you give me any insights to what soundproofing is already there? Is the metal under the floor, doors, etc. bare?
Hope this starts an informative and entertaining thread!

Hi, HighwayStar.

Going "quiet" is similar to going "fast,"--how quiet can you afford to go? Remember that this is money that you will never get back, so make sure that you get the enjoyment you hope to gain.

Both @CuttingToolGuy and @AgentOrange have given great suggestions. I saw your post "leaning" towards 2003-2011 Town Cars as I was typing this. The trunk lid actually has a sound-deadening layer installed, or at least the 2001's like mine does. You can in most cases add properly trimmed sheets of Dynamat or other sound-deadener into the mix.

In addition to sound-insulating the entire trunk, there are also two other "tricks" to keep trunk noise in the trunk. First, look at the trunk on a late '70's Town Car. They have a "carpet curtain" blocking the "over-axle" area off from the rest of the trunk. Have such a curtain made for your car. If you are also good at fabricating parts, you can cut or have cut a 1/8" sheet of Masonite to fit in the passenger compartment behind the back of the rear seat, with additional sound deadener fastened on the side facing away from the trunk.

In some of the "semi-inaccessable voids" in the body shell, you can also fill them with "Great Stuff" aerosol foam or similar. This is what Tesla does.

You can also have a padded vinyl roof properly fitted (or re-fitted if you have a non-padded roof already.) Part of why the great coachbuilders originally fitted such roofs had nothing to do with making a "faux convertible." Rather, the vinyl protected the padding that provided extra sound insulation.

You can also drop the headliner and install additional sound deadener. You can also do he same to the "c" panels and door panels. When adding the extra sound insulation to the front doors, insulate behind the speaker boxes too if you can get the sound insulation to remain in place.

Good luck.

 

[HighwayStar]

Hi, HighwayStar.

Going "quiet" is similar to going "fast,"--how quiet can you afford to go? Remember that this is money that you will never get back, so make sure that you get the enjoyment you hope to gain.

Both @CuttingToolGuy and @AgentOrange have given great suggestions. I saw your post "leaning" towards 2003-2011 Town Cars as I was typing this. The trunk lid actually has a sound-deadening layer installed, or at least the 2001's like mine does. You can in most cases add properly trimmed sheets of Dynamat or other sound-deadener into the mix.

In addition to sound-insulating the entire trunk, there are also two other "tricks" to keep trunk noise in the trunk. First, look at the trunk on a late '70's Town Car. They have a "carpet curtain" blocking the "over-axle" area off from the rest of the trunk. Have such a curtain made for your car. If you are also good at fabricating parts, you can cut or have cut a 1/8" sheet of Masonite to fit in the passenger compartment behind the back of the rear seat, with additional sound deadener fastened on the side facing away from the trunk.

In some of the "semi-inaccessable voids" in the body shell, you can also fill them with "Great Stuff" aerosol foam or similar. This is what Tesla does.

You can also have a padded vinyl roof properly fitted (or re-fitted if you have a non-padded roof already.) Part of why the great coachbuilders originally fitted such roofs had nothing to do with making a "faux convertible." Rather, the vinyl protected the padding that provided extra sound insulation.

You can also drop the headliner and install additional sound deadener. You can also do he same to the "c" panels and door panels. When adding the extra sound insulation to the front doors, insulate behind the speaker boxes too if you can get the sound insulation to remain in place.

Good luck.

Those are all good suggestions, I think my list of things to do has tripped in size since I posted this. I might pull this together into a list at the end.
In terms of investment, I am willing to do a fair amount, the idea is to get a low miles, late model Town Car, deck it out to suit me, and drive it as a poor mans Rolls Royce for as long as possible. So resale is not really a concern. That said, there are probably some limits on what I am willing to have someone else do.
Its good to know that there is some potential for adding dynamat. Other vehicles I have worked on had loose insulation that would not be an issue, but they were not anywhere near the level of a Town Car, so I did not want to assume it would be the same.

 

[w0by]

I'll have to agree, I had a 2001 Town Car and that thing was so quiet. I could slam on the gas and the engine you could barely hear it. If you were next to a semi on the highway going 75mph, you could barely hear the semi noise. I could put the windows down and somehow they made it so the wind didn't blow in at all, it was so quiet with the windows down, must be the design of the car. It was a great vehicle! My friend and I are both so picky about car cabin noise, and the Town Car just didn't really have any noise!

 

[dave42]

I will reiterate what I mentioned earlier. In my '03, I can not hear the engine. My tires are inexpensive Travelstar whitewalls, but they are quiet and on a good road I hear very little road noise. I usually have the music loud, but sometimes I drive in silence and by far the loudest noise is the wind turbulence from the mirrors. No amount of added insulation will make a difference in that. I would put sound deadening at the bottom of the list. I think tire choice will make the biggest difference.

______________________________

 

[wolf_walker]

Wind and tire noise by very far the most of what my high mileage 04 has. It's still mighty quiet.

 

[Ballyhoo]

I own a 1998, bought it new. I have ridden in the Tesla of my boss' between buildings the company owns. Simply put, adding more insulation would not make much difference, a few decibels at best. Both produce very close road/wind noise in the cabin. Zero engine noise unless you kick down the transmission under hard acceleration.