Engine box insulation / noise

I've been planning to remove the insulation inside my engine box, and replace it with a 2 sided foil that has a compressed plastic type material. I think its called cool mat or something ( it can handle engine bay temp) about 1/4" thick.
I was wondering if I remove the original insulation an install the new stuff. Will I get a lot more engine noise ?
I'm sure the heat insulation will be better with the new stuff. As the covering of the old insulation is in bad condition.
Just unsure of engine box noise.

I used a replacement that was similar to the original material. It did help with noise and was a huge heat barrier.

http://www.summitracing.com/parts/the-13590/overview/

Something about using that plastic insulator in the engine doesn't seem right to me.
I did use that stuff in my interior walls though!

I'm not worried about it causing a fire. I watched a video of it with a fire test. The worst thing that happened was minor charred edge after long exposure to intense open flame. I'm king of thinking of just adding the new stuff over top of the stock insulation= doubling the insulation and noise value.

I used dynomat and 1/2 thick fiberglass over top and after the engine gets hot the dog box is still cold, and all you can hear is the exhaust out the window, no engine noise inside

dodge man wrote:I used dynomat and 1/2 thick fiberglass over top and after the engine gets hot the dog box is still cold, and all you can hear is the exhaust out the window, no e

ngine noise inside

So you used both, on all surfaces? or just both on the lid ? Did you insulate the front radiator air inlet section of the box ?

yes I used dynamat even in front of the radiator, what I had left over I used on the front floor, I bought the 135.00 pack, and I covered everything with one sided aluminum 1/2'' fiberglass, it worked out great,

http://www.ebay.com/itm/1-2-4-X-10-Mighty-Matt-Auto-Insulation-Control-Heat-Sound-Noise-Audio-/281272809600?pt=Motors_Car_Truck_Parts_Accessories&hash=item417d2a7880
this is what I used its 1/2'' he has it in 1/4'' also, you just glue it on,,

search the forum here, I've posted contact info for the guy I bought my kit from a few times. Its a great kit and very quiet, iirc, quiet ride also sells a kit.






eta: Dodge Man, get some foil HVAC tape from home depot and tape your edges down so the matting doesn't get wet, it will last years longer if you do so.

thanks slowflapper, i'll do that I never thought about it great idea,