So I purchased a new carpet from Classic industries and ordered it with the Mass Backing. Will that eliminate the need to add sound deadening mats like Dynamat or Killmats? Or is the mass backing good enough. I don't want to add a bunch of weight to this car I'm trying to keep it as light as possible while also making it semi livable as a daily driver with a radio and AC etc.

 

Depends what engine combo is under the hood and what exhaust you're using. Not all setups are as loud as others.

Sound dampening is one of those things that is easy to add later on if you just see how it turns out. It's also near useless until you go all the way so it's kind of an all or none thing.

 

I'll put it this way, putting the carpet one time was a total pain in the ***, I would hate to do it a 2nd time to add the Butyl down. Keep in mind, if you get a good coverage, it not only reduces rattles and vibrations, it also reduces heat from the exhaust. A lot of people say don't do the whole floor pan, thats up to you, but my car is much better with Mass Back carpet and Butyl mat (I used Kilmat).

 

Me personally, I didn't use it and the mass backing is thick enough to drown out most sound and keep out heat from the cat, That's just me

 

I've been using this stuff for deadening mat, it's lighter than other products (9lbs per roll) and seems to work better. Instead of just being butyl and foil it also has closed cell acoustic foam has a top layer. They have a slim product that is even lighter, 7 lbs for 11 square feet. We plan to start selling it later this summer. I currently have a couple rolls in stock if you want to stop by and check it out. I could sell you a portion of a roll if you want to try it out before getting a whole roll. It seems to conform better for easier install also.
Sound Deadening | SoundShield | United States (soundshieldusa.com)

 

Hey, Steven, I have a 89 Iroc with 3.23 rear how do you like the Hawks 3.73 rear...may buy the same rear gears setup and if you run it on the drag strip how is that working out...Thanks 2Irocs

 

Not to start a disagreement, but you want the Foam on the interior plastics, not the floorboard.

I like it a lot, great unit. I have not been to the drag strip, but im sure it would hold up just fine, my LS1 doesn't make anywhere near the amount of power a 8.8 can take

 

This stuff has foam, butyl and foil all it one material.

 

does your LS1 make as much power as an LS3?

 

Your shop is an hour away so that a little hard for me to get out there with my schedule (5 kids, wife, job, gym, work etc. LOL) but I ordered the thinner Kilmat (50mil) and just one box because I wanted to do the roof under the headliner, the rear hatch area and some parts of the floorboard around the exhaust and driveshaft tunnel. One box is 17.5 lbs of added weight so I'll do that and then with the mass backed carpet it should be pretty quiet inside relatively.

 

In the same boat here. Was thinking of laying down some mass loaded vinyl instead, but there is a good amount of heat radiating up from the floor board, so I might just do the whole thing with sticky butyl.