Need Help w/ Sound Insulation for '65 Coupe

Ferf

Member
Dec 6, 2002
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I am in the process of starting to reassemble my '65 coupe. At the moment the car is a complete shell with every removable piece off the car. I am looking to get some sound insulation to put into the car.

1) What do you guys recommend using?

2) Where do you recommend putting the sound insulation....roof, floors, trunk, inside doors, firewall, etc?

3) How much do you think I will need to do the entire car?

The car is painted black so whatever I use must be able to withstand the car sitting outside on hot summer days.

Thanks!
 
+1 on lizardskin. we've done a couple cars with it at the shop. excellent end result, good heat/sound insulation. cleans up with water until it dries! just make sure you get rid of ANY rust before you spray it, with por-15 or something similar, as this REALLY seals it in.
 
Spend the money on something better than what they sell in the restoration catalogs. The thick carpet looking stuff just doesn't cut it and when combined with carpet can lead to issues with clutch / throttle pedals!
 
You can never go wrong with Dynomat. You can buy it 12"x12" sheets or on rolls. It's not the cheapest thing on the block but it definately works the best. It will add a tremendous amount of weight to the entire car; roughly 250 to 300 pounds if you do the floor, doors, firewall, trunk, roof and hood. This will make it quiet for highway rides but be a detriment on the track. I'm not sure of your project goals or how quiet you are looking for. If you want a little quiet and save weight go with the spray on stuff, if you want audiophile quiet go with the asphalt matting(Dynomat).

BTW I have heard of people taking thier off road trucks and having spray-on bedliners shot all over the insides to make them easier to clean and for sound deadening. just an afterthought.
 
Mustang monthly just did an article on sound proofing car. Summit sells the same heat/sound sheets for way less, but just not cut to fit. They also use minimal dynomax sound dedeaning stuff. I saved the article, and am going to do it the same way.

Have a look at their website, or at the newstand.

Nate
 
I work at Ford and have responsibility for sound insulators and carpet on several programs. When it comes to sound insulation, the method of control depends on the source and the frequency of the sound.

Low frequency sounds (suspension noise, engine noise, exhaust) respond well to mass. Dynamat, etc. Weight kills low frequency sounds.

If you want to address higher frequency sounds (wind noise, etc), the answer is a light fluffy absorber. A cotton shoddy (sheet of tightly packed fiber threads) is a good, cheap way to go.

Typically, a good sound package starts with a good dash insulator first and foremost. Get one with a soft face on the front (facing firewall) with a harder, heavy face on the back (facing the driver). This will give you basic sound insulation. To go one step further in the IP, take pieces of loose shoddy or other absorbtive material and place it anywhere there is room between the dash insulator and the IP, duct work, etc. You can staple it to the back of the dash insulator where you have room. For most benefit, don't compress the material when you install it (just like when installing the pink stuff in your house).

On the floor, the best bet is to add mass as most of the sound coming through will be low frequencies (suspension, engine, exhaust, etc) that propagate through the sheetmetal. Use dynamat, spray on, etc.

Make sure you have a complete door seal - the big plastic cover that seals the wet part of the door from the dry inner part is a must. I have replaced this piece with dynamat before with good results. Just make sure it covers every opening that isn't used by a moving part. Don't put any soft insulation outside this seal - in the 'wet' zone - but covering the back side of the door trim with it is a good idea.

Improving wind noise on an old Mustang is a challenge but you can help the situation by stuffing lightweight absorbtive material behind all the trim (pillars, door panels, quarter panels, under the package tray, etc).

There are some big passages between the trunk and passenger compartment that can use some stuffers - for ease of install, use the soft stuff. Seal off holes in the package tray before installing the trim.

Cover all unused holes in the body. They are 'hot spots' as far as noise intrusion is concerned.
 
I work at Ford and have responsibility for sound insulators and carpet on several programs. When it comes to sound insulation, the method of control depends on the source and the frequency of the sound.

Low frequency sounds (suspension noise, engine noise, exhaust) respond well to mass. Dynamat, etc. Weight kills low frequency sounds.

If you want to address higher frequency sounds (wind noise, etc), the answer is a light fluffy absorber. A cotton shoddy (sheet of tightly packed fiber threads) is a good, cheap way to go.

Typically, a good sound package starts with a good dash insulator first and foremost. Get one with a soft face on the front (facing firewall) with a harder, heavy face on the back (facing the driver). This will give you basic sound insulation. To go one step further in the IP, take pieces of loose shoddy or other absorbtive material and place it anywhere there is room between the dash insulator and the IP, duct work, etc. You can staple it to the back of the dash insulator where you have room. For most benefit, don't compress the material when you install it (just like when installing the pink stuff in your house).

On the floor, the best bet is to add mass as most of the sound coming through will be low frequencies (suspension, engine, exhaust, etc) that propagate through the sheetmetal. Use dynamat, spray on, etc.

Make sure you have a complete door seal - the big plastic cover that seals the wet part of the door from the dry inner part is a must. I have replaced this piece with dynamat before with good results. Just make sure it covers every opening that isn't used by a moving part. Don't put any soft insulation outside this seal - in the 'wet' zone - but covering the back side of the door trim with it is a good idea.

Improving wind noise on an old Mustang is a challenge but you can help the situation by stuffing lightweight absorbtive material behind all the trim (pillars, door panels, quarter panels, under the package tray, etc).

There are some big passages between the trunk and passenger compartment that can use some stuffers - for ease of install, use the soft stuff. Seal off holes in the package tray before installing the trim.

Cover all unused holes in the body. They are 'hot spots' as far as noise intrusion is concerned.

This is great info. I have been searching for the past few days as to where to install my dynamat and where it is a waste of time and money. It just seemed to me to be overkill to blanket the whole car and you confirmed that for me.

Thanks for sharing your knowledge. You saved me a some serious $$$$

RV
 
This company sells kits that use strips of Dynamat, covering 30-50% of the surface, claiming that it helps just as much as covering the entire area. What do you guys think?

Car Insulation, Truck insulation, Auto Sound Insulation, Auto Heat insulation

At the store they had a demonstration of dynamat extreme. There were 2 bells. One had a piece of dynamat 1 inch by 1 inch stuck to the bell. The bell would not ring it was a mere thud. The bell without the dynamat of course rang as normal.

So yes I believe that it isn't necessary to cover the entire surface. I just didn't know how much needed to be covered. Thanks for this link as it states 30-50% in strips.

Now if you are trying to compete in one of the decibel drag race stereo contest I could see that you would want to blanket the vehicle. That's not my intended use so I think what QuietRide suggests is probably true. I'll find out once it warms up a bit.
 
Most people seem to cover the whole surface with Dynamat, but I can imagine that only partial coverage is sufficient, like QuietRide claims. Of course, it saves them money if they have to supply less Dynamat, but on the other hand, it would be kinda stupid if they supplied too little of it, so that their rather expensive product didn't help any.

For the do-it-yourselver, using only strips of Dynamat would save both money and weight. I don't know if placement of the strips is critical but QuietRide makes no mention of it and they probably would brag about their extensive research on correct placement if it were.
 
I spent some time researching before doing the sound deadening project on my car last year. My research lead me to this product:

http://www.raamaudio.com/cgi-bin/index.cgi

There was a link to an extensive analysis done some time ago comparing a handful of the different companies products. Raamaudio rated very high as I recall. The best part is the price is about half the cost of Dynamat products and the quality is very good. I am very pleased with the end result, although I still need to finish my trunk area this spring.
 
THis is probably outside what you want, but maybe some will find it useful. If you order deluxe carpet underlayment from Virginia CLassic or CJPony, you get a big roll of tar mat. I get a really great product from Kentuck Mustang. It's made by a company called Snake Oyl. THe firewall insulation is exactly like what oz describes, and all the rest of the pieces are like that.
Ssnake Oyl Products

We do put the water shields on the doors, but may try the dynamat-neat idea. THe restored cars we do are pretty quiet inside with the Snake Oyl products. May not be a quiet as dynamat or lizardskin though.