I think if you can make or install some heat shields around the pipes, this will help tremendously, and make whatever you put in the inside of the car to reduce heat more effective.

One of the guys in our club made aluminum heat shields and installed them under his flooring. The bottom of the car looks similar to the C5 pan now. I would take some 3" or 4" pipe and cut it in half or jsut get some sheet metal and bend it to fit over the exhaust pipes. You can then bend the corners down and tack weld them to the pipes so there is no rattle (this is similar to the factory heat shields over the cats and between the rear spring and the exhaust pipes).

Also, gluing dense rubber to the floor will reduce noise transferred through vibration. That is one of the features of Dynamat. The Frostking stuff doesn't do a great job with this, but the foam is partially effective, and may do the trick for some. What you are trying to do is reduce overall sound wave vibration transferred to the body of the car. That is why you see only strips applied to most areas, and not a full covering.

The aluminum foil face will help reduce radiated heat, but you have to seal every joint with foil tape to make it fully effective. It keeps the heat and cold out, just like HVAC ducts. The Reflectix is a great product, and cheap. I stuffed some of this in my Torque Tube tunnel of my C5 when I put the ceramic coated tunnel plate on it. The combination made about a 40 degree difference in my console. Change in the console would actually burn my skin after a long trip. Now, it is not even noticeably warm.

Whatever you do to your car, please share it with the Forum, we can all learn from each other.

 

Another thing I found out when doing mine is when I was doing the tranny tunnel under the console, I had a lot of wires making contact with the reflectix, it looked like a short waiting to happen. Ran up to the tire store and got an old tractor inner tube out of the recycle pile and took it and cut sections out of it and glued on top of the reflectix wherever it looked like the possibility of an accident happening. Only took a couple of minutes to cut it up with scissors and the spray on 3M held it perfectly. Also used it under the jack storage compartment, really helps stop rattles from it bouncing around.

 

Wuttin - good comments about Frost King. I had it installed in my C5 and did not notice ANY difference. Believe me, I would rather have it work than complain about it. Sold the C5 after 5 years, now considering Dynamat in my C6. I love the car as-is, but would love it even more if quieter.

 

Good discussion. As you can see by the following picture, I'm giving this issue some thought, too. What I'm hearing here is, some people think one product works fine for both purposes, some people think the other works fine for both purposes, and others feel the best choice is both products used together. Assuming $$ is not the consideration, would we agree this is the best choice? Also, is using both products going to make the carpet too fat? One poster was against the Reflectix alone for that reason. Too thick is not acceptable.
What about the stuff Corvette Central sells ("Upgrade")?

 

The only thickness issues I had when I applied Dynamat Extreme topped with Reflectix in my 79 were in the storage areas in the rear and the kick panels. I needed to trim back the Reflectix just a touch to get it all to fit, snug but OK. No probem at all with the pedals.

For my money, the Dynamat/Reflectix combo made the most sense and I managed to do just about the whole car for < $250.

If price is not an issue Dynamat Extreme topped with their Extremliner is a good bet (sound and heat addressed):
http://www.hifisoundconnection.com/S...id/0/SFV/30046

Stinger offers similar products under the Roadkill brand. Dynamat and Roadkill is supposedly the ultimate combo (according to some pro-installers I've spoken with).

Do some homework and talk to some pros to make the best informed decision. Lots of choices, but many of the products are similar and the incremental increase in performance you get may not be worth the jump in price in our cars. You just don't get the extra sound deadening benefit with the top down and the wind roaring. Go with what works for the least money that will not have to be replaced or upgraded in two years time.

 

Well I just bought both dynamat and reflectix. Going to hopefully do it tonite when I get back from work. I bought a dynamat extreme bulk pack and reflectix + accesories totalling about $170.

 

OK, here's my 2cents... You don't need Reflectix in the storage compartment; there isn't really any heat coming in back there (lots of airflow available and exhaust is much below the compartment floor). If you need sound deadening in the storage compartment, do so. You only need heat insulation from the firewall back to [and including] the vertical bulkhead behind the seats. If you want heat insulation AND sound deadening, I would find a sound deadening product and put heavy-duty aluminum foil down on the surfaces before you put in the sound deadener. Good luck.

 

I'm still taking notes...

A good buddy a couple years ago restored his '65 Impala, and when the interior was finished, I put my head inside the window and it "felt" like a sound recording studio! The car was incredibly quiet. It was almost unnerving.

I just called him and asked whet he used, and he said he used to have Dynamat and hated it. He took it out and used this insulation stuff that is used for those big commercial metal containers... said it was metal on one side and rubber on the other. He said he put the rubber side down on the floor and the sound difference was incredible. Heat was reduced too, but he was less interested in this. He could not remember the trade name of the stuff, but he is checking it out and Ill post it in a couple days.

The thing is with me, Id like it quieter, but Im not a freak about it. Im not a stereo guy, and Ill be using the stock '69 radio, so I won't be expecting symphony quality. Regarding heat, I of course want to reduce heat in the cockpit, (it IS a C3) but its a 350/300 and it shouldnt be too oppressive anyway.

What Im saying here is I am not expecting remarkable results, but as the interior is completely apart its obviously time to do this. Correctly. Once.

I'm not willing to half-azz it to save a couple dollars if I can get it right the first time. Of course, I don't need to waste money, either.

 

This was my thinking also. I bought two rolls of reflectix and ended up only using one. I was painting the door jambs last night and noticed the frigging Fatmat in the back had pulled loose again. DONT WASTE YOUR MONEY ON THE FATMAT! Dynamat stuck just fine everywhere.