the new stacks have a pretty painful drone at 2200rpm... NOTHING like the 5" straight pipe had at 2500, but in the 2000-2200 range (right where you cruise on the highway! ) they'll hammer on ya pretty good...

the dynomax bullet I ordered earlier this week had already arrived, but I decided to lay a 1/8" sheet of lead on the inside of the roof first... I had already done two layers behind and under the seat, and one layer everywhere else... everywhere but the roof.

sure enough, made the truck MUCH more comfortable!!! comfortable enough to leave it alone for a while. but I'm gonna go back and put some more deadener up there pretty soon to get it nice and quiet in there

Forrest

 

oh yeah, the resonator will probably just collect dust for a while! LOL!

Forrest

 

Did you just pull the headliner down and glue it up there or what? I'd be plenty interested in doing this to the floor, where did you get it?

 

one of my buddies owns a lead supply, so I get it cheap (free)

I've experamented with lots of different adhesives... I started out with 3M 77 spray adhesive, then went to Liquid Nails Construction & Remodeling. for the roof I used Liquid Nails Paneling & Molding. it grabs instantly, lists a service temperature of -20 to 140*F, and lists shear strengths of 125psi after 24hrs, 200 after 48hrs, and 325psi after 7 days. the 1/16" lead is 4lbs/sqft, so I think it'll be alright. the biggest concern is the 140* service temp. I live in Dallas, and that sun can beat down pretty hard, but my truck is white, and the layer of metal you see above you isn't the piece of metal that sees the sun.

as someone who has messed with this sound deadening stuff a lot and who has stacks, I would HIGHLY advise you to just hop on ebay and pick up 70sq ft of Brown Bread sound deadener for ~$150 and go to town... I would put two layers on your roof and two layers on the back wall of the cab. if you weren't running stacks, I would say don't worry about the roof or just run one layer, but with the sound exiting up there, it makes a HUGE difference w/ the stacks!

honestly, I don't know the cost of lead sheet. I do know that metals have gone up across the board, and lead is no exception. it might still be affordable compared to high dollar sound deadeners, but it might not...

Forrest

 

What is the weight comparison of the brown bread deadner to the lead sheets? I know the lead sheets can easily get over 150lbs of additional weight.

Edit-

 

I made a mistake in my original post... I used 1/16" sheet, not 1/8". The 1/16" = 4lbs/sqft.

 

How does the lead sheet compare performance-wise to the sound deadener sheets they sell at car audio shops?
Chris

 

well... I would imagine that it actually compares quite well... it adds a LOT of mass... GregL (LsFarm) (the "Noise ****") swears by it... recomends a layer of lead followed by a layer of sound stop foam.

the key to stopping vibration (the transmission of sound waves) is adding mass... I would say that lead does this better than anything out there, but I'm sure there are other factors involved.

Forrest

 

I think it is more resistance to movement than adding mass though. Otherwise Dynamat would be out of business if their stuff weighed 1/10th then it only works 1/10th as well if it were only a function of mass.... Mr. Laurent defenitely has a good deal of lead in his truck.

Sort of on this same note how big of a difference do you think an aluminum lined hood liner would have over a non lined liner for keeping heat in, same thickness and density of foam. Measureable or insignificant?

 

well, like I said, I'm sure there are other factors involved... and if I didn't get the lead for free, I'm sure I would spend way too much time researching because I'm a poor bastard, but all the TDR threads I read pointed me in the direction that lead sheet was about as good as it gets. and realize that it's VERY difficult to get lead to "vibrate". if you've ever held a sheet of lead in your hand, you'll see what I mean.

anyhow, yes, a reflective liner will keep heat in vs. a non-reflective liner. and that I know for a fact!

Forrest

 

yikes Forrest - I always thought that lead is poisonous...I do hope you spend some time researching this....it could be harmful to you and your passengers.

 

don't worry, we're not licking it as we cruise down the road! LOL!

(it's harmless in this capacity)

Forrest

 

Forrest I had to laugh at that one. No more tranny wars or oil wars so it gets rather dull around here. Jim

 

And if you do get hungry and shave a bit off, you might start feeling better about being a "poor bastard"!

 

Only way the lead is bad for you is if you somehow breathe it in or eat it.

Yea I know what you mean, the price was right. I was just trying to make a point there is a lot more to it than just weight, the TDR thread implied it was all about adding mass to cure the noise issues.