Cabin insulation sound and heat recomendations

[Silver dude]

Been looking to quiet road and wind noise. In my Xterra. The roof rack makes a howl in the wind. I would suspect a liner or insulate of some kind under the head liner would reduce the noise to a reasonable volume so that my passenger and I could talk at a reasonable volume at 70mph. Does any body have experence with such products? Looking for something lighter weight, and afforable. I have my xterra dampened with a mat like dynomat already. It cleaned the acustics and made the stereo better but did very little to stop road noise.

 

[southpier]

some of those sound deadening products have a two or three step process so you could probably keep adding layers $$$.

http://www.hushmat.com/ http://www.lizardskin.com/ http://www.secondskinaudio.com/ http://www.sounddeadenershowdown.com/cgi-bin/index.cgi http://edeadsounddeadening.com/ http://soundown.com/

most roof rack companies offer a front air dam. good place for stickers!

 

[Bdiddy11]

I've been looking into some closed cell foam mat stuff called "volara". It looks similar to the stuff you use for camping pads and yoga mats. It looks similar to the name brand stuff that sound deadening companies use. Another option for areas that wont get wet is using pillow/blanket batting. The white fluffy stuff. Supposedly its flame retardent as well.

A lot of people have used that Peel n' Seal stuff you get at hardware stores but it's asphalt based on one side so apparently it smells after applying and on really hot days the smell can come back. That's what I was originally going to use but not sure if I want to deal with those smells, especially with my wife and baby in the car.

One thing that I've thought about as for insulation is using emergency blankets. Those thing tinfoil looking things. I did some reading up on it and seems like it could be a viable option. Coat the roof/floor with the emergency blankets first for heat repelling and then the volara matting anywhere I can.

 

[Treenail]

Mylar 'space blankets' aren't going to add much 'insulation' in this application. Foils will conduct heat very well and do a great job of reducing heat loss from convection. The insulation gain you will get here is from a vapor barrier not for heat really.

The best insulations trap air and reduce air movement. Closed cell foams work really well. There are some mylar covered bubble wrap products claiming wild R values. Its just not possible with the materials to get those sort of R values.

If you're interested in sound insulation you're not likely to gain much by installing anything in the head liner. Glass conducts sound pretty well.

Go to the source of the noise...the rack. do you have any tubes with open ends? Have you ever carried ladders on top? They whistle like mad! Jamming foam chunks or spray foaming the rungs helps a LOT! Its going to be a challenge to find the source of the rack noise. You could strap your sound engineer to your rack like luggage and head down the road. With the engineer's ear up top they might be able to find the resonance. Ohhhh...safety first! Make sure that they wear a helmet and eye protection!

Tom

 

[1leglance]

If you look up my Ozwagon Troopie build you will see my setup by set process that made a huge difference with a diesel rig in the brutal Phoenix desert.
I painted with this micro-sphere latex stuff that insulates & sound deadens...that really helped & was easy
Then added a layer of FatMat all over the place.
Then added the Home Depot alum bubble wrap stuff.
At each stage I drove around a bit to get a feel....by the end it was a rival for my wife's 2010 Camry

I will be doing the same thing to my 1970 Suburban and once I also replace the door seals I expect equally great results and it wasn't that much money.

 

[Ponyracer]

Any way to reduce the noise coming off the rack? I don't think sound deadeners are going to do what you want, your still going to hear the noise. Air dams, airfoils, some way to change the air moving under/over obstructions on the rack? This will usually cure the howl or at least limit it.

 

[corax]

As stated, track down the rack noise first. My Yak load bars howled until I added the lightbar which tied the front and rear bars together. Try an air dam at the front - you can make your own out of a piece of lexan from your local hardware store for less than $20.

If you're still interested in sound deadening, do some reading here: http://www.sounddeadenershowdown.com/
"More about sound deadener and the sound deadening process than you would ever want to know."

You might also run across talk of "Lizard Skin" as a sound & thermal insulator. Save your money and make it yourself: alternative to Lizard Skin thread or Ceramic Insulation wiki

 

[Buliwyf]

Form some house building styrofoam insulation into an aero shape, hollow out it's bottom so it'll fit over your racks rails. Apply fibreglass or bondo over foam to make it strong.

Model airplane builders do it all the time.

 

[FellowTraveler]

Air Tabs

While I have no affiliation w/airtab I can suggest their product to drastically reduce even eliminate the noise and drag on your roof rack loaded or otherwise.

Drag plays its part starting @ around 40 mph.

While the Air Tab may not be pleasing to the eye of many it works and that is a good thing!

 

[LACamper]

Have you undercoated your xterra yet? It on my list of mods.... There's a lot of road noise even in a stock x.

 

[Silver dude]

Yeah I undercoated it with a sound dampener coating from Second skin. Did very little to silence. Did help with the rocks and small bits of gravel hitting the metal being quieted. Though its a water based coating and can't say I would recommend its use as it can't withstand rigorous offroad use.

The xterra is pretty quiet, just on windy days or high highway speeds the rack makes a whispy wind noise as the air blows over the air dam. I'd try to make changes to the rack but I also tote around kayaks 90% of the summer which makes even more noise and is even harder to silence.

 

[Treenail]

While the Air Tab may not be pleasing to the eye of many it works and that is a good thing!

What do you know about airtabs? Before and after mileage improvement stories? I've read their website but I've wondered if they are worthwhile for anything besides over the road size box trucks.

Tom

 

[FellowTraveler]

What do you know about airtabs? Before and after mileage improvement stories? I've read their website but I've wondered if they are worthwhile for anything besides over the road size box trucks.

Tom

Apparently, you did not view their entire site, last I looked their were pickups, vans and sports cars w/airtab (s) too.

While the airtab concept maybe new to many here the states in Europe an other parts of this globe they have been an aftermarket item (slightly different design) for decades used mostly on sports cars/vans and before sun/moon roof openings, then on trailing edge of roofs/trunks.

 

[corax]

Here's some reading on Airtabs and other vortex generators for anyone interested in how they work
Blowing the Vortex, Part 1
Blowing the Vortex, Part 2
Blowing the Vortex, Part 3
Blowing the Vortex, Part 4

 

[Treenail]

Apparently, you did not view their entire site

Oh yes...I found that site a couple of months ago and read it cover to cover.

Claiming improvements in mileage without independent testing leaves me a little sceptical. Not that I think that they're snake oil though.

I'm wondering if anyone has used them on a smaller vehicle with enough before/after mileage to decide how much they help.

http://stonerradiator.com/images/dsc00667.jpg

This is what my 'expo' vehicle looks like...aerodynamic ain't in it!

Tom