[jgorm]

This was an attempt to quiet the rig down a bit. I used the 1" west marine foam on the inside of the doghouse and I used the 1/2" under the carpet. It costs a grip, like $300, but it was worth it. It didn't make it silent, but it did make a big difference. I could talk (loudly) to Alicia in the back of the coach, but we no longer had to yell. Alicia said that she thinks it made it 50% quieter, that might be a streach, but it was worth it. I plan on adding more of the 1" on the top of the inside of the metal over the engine (under the dash) and hope that will help some. I might do a bit more work on the doghouse because there is some heat that comes from the rubber itself, and the doghouse corners. I didn't add the 1" insulation near the ends of the doghouse because they were closer than the recommended 6" from the headers. The insulation did touch the heat shield on the turbo, so I "massaged" the heat shield with my fist until it hardly touches the insulation, but the lip of the turbo. Before the massage, the doghouse would vibrate due to the contact with the engine (not good for noise control!). I checked the insulation for singeing, discoloration, and other signs that it got too hot, but it looked perfect. I had the EGTs over 1100 for at least 20 minutes going over the grapevine and peaked at about 1223 until I slowed down to about 40 mph. If it can take that, it can take whatever I can throw at it. I made cardboard templates and then cut the insulation to fit. I spend about a full day on everything including the fake dynamat (jiffy seal) that I put down on the floor under the 1/2 acoustic foam. The 1" foam on the sides of the doghouse was a bit big, and would have worked better if I stuck it to the metal instead of the plastic cover thing.

More pics here.

 

[beaker]

I did the same. I used some sort of asphalt sound-deadening material . It seemed to help. I also pulled the instrument cluster and the the radio. I was able to put a fair amount of insulation on the bottom side of the dashboard this way. I also put some on the lower panels of the dash, the inside of the bin on the doghouse, and the inside of the front doors. I have not gone behind the driver's area yet, but there are a lot of spaces that could resonate including the floor, roof, and sides. I'm afraid if I get carried away that I'll end up adding another 300# to an already heavy vehicle.

 

[quigley73colo]

Excellent thread! Thanks for the how to! I need to do this !!!

 

[OgopogoSalsa]

nice, great to see! I will definitely be doing something along these lines in the next two months. Thanks for sharing