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I've got my 1968 Camaro put together finally. I enjoy driving it but it is still louder in the interior than I like. Here's what it has in regards to sound:

- Dynamat Extreme on the firewall and whole floor pan
- Dynaliner (the foam stuff) on the firewall and the front of the floor pan
- Home depot cheapo black carpet
- Dynaliner on the roof
- No headliner yet
- No dashpad yet
- No sail panel interior pieces yet
- Dynamat in the door skins
- Home-made pressboard with Home Depot carpet door panels
- Polyurethane bushings
- Stock springs

The motor is...
- Hopped up 350 with heads and a rumpety-rump cam
- Full length headers
- 2.5 inch exhaust pipes with H pipe
- Dynomax super turbo mufflers
- Probably some exhaust leaks on the headers


I'm trying to figure out what I should prioritize doing to get the interior noise down. There's a good deal of road nose and also a lot of engine noise. It doesn't really sound like it is a lot of exhaust noise... the mufflers are pretty quiet I think. I hear a lot of noise coming from the engine bay.

This is the only 1968 car I've ever driven in so maybe this is just how it is supposed to be :)


Any suggestions?

https://lh3.googleusercontent.com/a...cZh3ysFNx4s6lbQLa1ToqSsZNQMTlxA=w1262-h946-no

https://lh3.googleusercontent.com/E...77JKyG7-jNSsKD5Eu4Cxv96svRZC6_g=w1262-h946-no


https://lh3.googleusercontent.com/e...VsEA7zhN9aiyvah4gDeBPRKrWWI5QWg=w1262-h946-no




Thanks,
Sal
 

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Headliner, sail panels, kick panels, package tray all need to be in to minimize cabin "noise". Your Dynamat/Insulation/carpet is a good foundation.

With that said the 1st gen, compared to modern vehicle, is ...rougher around the edges (ride, noise)
 

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I suggest a factory firewall pad. I'm not familiar with Dynaliner so not sure how it compares. The dynamat can stay on the firewall, you might have to remove the Dynaliner to put the factory pad in. I agreed that the more of the interior in place the quieter the cabin will be.

Jeff
 

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Holy Sh!t, I don't have any of that noise dampening material on the floors, doors, firewall or roof and it sounds normal to me with loud flowmaster mufflers. Its not a new car and will never sound like one.
 

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This is one of the best websites that shows how you can address/reduce noise and heat. There is not a one all be all product that does everything. There is sound protection and heat protection. I have ridden in a couple of cars that have this setup and they are a lot quieter than mine but.... you have to look at the costs and weight they add. Are you willing to go that far? There are a lot of little things you can fix, door seals good? Firewall holes sealed up? Add some heat protection underneath the headliner. Add some tint to your windows. Many more.

https://www.sounddeadenershowdown.com/

I agree with Bob though. Our year cars are not designed like newer ones. You can do some but if you drop in a high HP motor with a big cam and loud exhaust and can’t expect your old car to be like a new car. Heck, even in newer cars with cam/exhaust upgrades, they aren’t quiet either. My car has a lot of modern updates, at the end of the day though it is still a 68 camaro 😎
 

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My all original 69 is a lot quieter than my hot rod Camaro with Dyno mat! The original with 55k miles has a new crossflow muffler with 2" pipes and original exhaust manifolds and a 300hp 350. Many of the new cars use Styrofoam insulation and I have used it as well and works good and is light weight. Turn up the stereo and enjoy the sounds!!!
 

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You can install sound insulation under the hood to reduce engine noise. There are some that are molded to fit your particular Camaro. Some of the aftermarket hoodliners fall off after a few miles.

I use Dynamat Hoodliner. It is a foam insulation that has reinforced foil sheet on one side. The other side has glue that sticks to the hood. On one truck that I had, I cut it the shape of the triangles and rectangles that are under the hood between the hood's frame. Most people just stick the sheet on as one great big piece. It did not fall off for at least 15 years. (I sold the trunk after 15 years.) It can be washed if it gets dirty.

It does not weigh much and it does reduce engine noise.

http://www.dynamat.com/automotive-and-transportation/automotive-restoration/hoodliner/
 

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You have to completely isolate and line your trunk. It is a huge resonator. Dampen it and completely isolate it from the cabin. Makes a big difference.

Don
 
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Exhaust ran all the way out the back ?

insulate hood, finish interior, not much more to do beside ear protection.
noise canceling headphones ? you'd at least look cool then.:)
 

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Once again, you have created your noise issue with your engine mods. At a stop sign you can't even hear my stock set up engine running it is very quiet . . . . certainly not as cool as our hot rods and I have 5 of those and I love the sound!!! Just an old guy talkin.
 

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1969 Camaro RS Z/28, M20, 3:55
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Sounds like you did what I basically did but I also added 1/4 inch carpet insulation over the dynomat and my car is ten fold quieter than it was and no heat what so ever coming thru.
Curious, what type of carpet insulation, home use or automotive?
I'm there now and was thinking if insulation would work over the Dynomat (though I'm using a competitors). I'm on the fence.
 

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Curious, what type of carpet insulation, home use or automotive?
I'm there now and was thinking if insulation would work over the Dynomat (though I'm using a competitors). I'm on the fence.
I use Thermozite insulation over Dynamat. I get it on eBay.

Don
 
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