Dynamant Weight and Performance

[Kitsune]

I am interested, or at least currently researching, the use of dynamat in the E90 to both reduce road noise and improve sound quality. I'm not sure what placement and where would be best, but say that it was a near full install. About how much weight would that add? Has anyone worked with this?

This car will probably be 95% street and 5% track.

Edit: Dynamat Extreme is what I was considering, due to decreased weight and, well, obviously increased performance.

[URBAN LEGEND]

I would wait until you get the car. There is really no road noise inside the car.

[JuniorDee]

Originally Posted by URBAN LEGEND

I would wait until you get the car. There is really no road noise inside the car.

I agree, even with an x-pipe its not that loud.

[J08M3]

In my opinion part of the fun of the M3 is the decreased sound deadening materials you find in more luxury type cars. This is supposed to be a sports car you want to hear all the noises.

[Kitsune]

Originally Posted by J08M3

In my opinion part of the fun of the M3 is the decreased sound deadening materials you find in more luxury type cars. This is supposed to be a sports car you want to hear all the noises.

True. I was thinking more about increasing the quality of sound inside than listening to what is outside. The thing is, unless I completely surround the engine and forward compartment of the car in the stuff, I don't think it will effect that particular portion of the sound. The exhaust, however, yes it might.

And I just realized I spelled Dynamat wrong... somehow.

[808MGuy]

Originally Posted by Kitsune

True. I was thinking more about increasing the quality of sound inside than listening to what is outside. The thing is, unless I completely surround the engine and forward compartment of the car in the stuff, I don't think it will effect that particular portion of the sound. The exhaust, however, yes it might.

And I just realized I spelled Dynamat wrong... somehow.

If you do a full install meaning floor, roof, doors, trunk, and firewall you could easily go through 4-5 rolls (approx 40 sq ft per roll). In my last car, I used 1 full roll just on the two front doors. I recall that each of those rolls weigh about 40-50 lbs so you're adding around 200 lbs. IMO, I wouldn't use dynamat. Too expensive and hard to work with. There are other brands out there that do the job better and are easier to work with like RAAMat or Cascade.

[bigjae1976]

I would do the areas near the speakers, the doors in this case. That will yield the biggest results.

Rear quarter panels and the rear deck are common areas for rattles. And of course, the trunk lid.

The floor & roof would be a waste since the floor in a BMW is very well damped abd the CF roof should be VERY stiff. You'll probably have a much larger issue of too much damping, especially in the trunk.

[DiamondGCoupe]

What about the wheel wells, there has to be some way to reduct tire/road noise aside from purchasing higher profile tires. Albeit much quitter than my previous car, there is still room for improvement. It's no 7-series but I shouldn't have to keep the windows down and blast the music just to avoid hearing the road.

[Eliminator]

I work in the business so I may be able to help. The weight, depending on thickness, is about 1.5lbs./sq ft. We also have light weight dampers, which are effective and less dense... using glass beeds. We manufacture and sell to the distributors private label. It is a butyl compound with aluminum foil. Excellent vibration damper. Keeps panels from vibrating like speakers. These are not insulators. Insulators are like pillows, padding and have to be thick and fluffy. They absorb air borne noise from inside the cabin. Like people talking... so better articulating index is the result. Back to damping. Dampers stop vibrations. So sounds that light up - vibrate - the panels will lose their energy quickly. ie. engine noise - 4 cylinders are notorious at 250 Hz - don't know V8's, road bumps and roads noise will not resonate the panel. Dampers are very effective - most common applications - on Doors, Wheel house, Front of Dash, Floors, Roof - great for rain - and last, rear quarters. Hot Rodders also use them for heat insulation. Ok, it works. Always on the inside of the car though. Can sustain only 250F continous. Aftermarket folks never place properly, so what they do is called wallpapering. Just cover everything. We use laser vibrometer and Head Acoustic recording devices to determine the natural resonant frequency of the panel in question and which area "lights up" the most. These pads are very effective with only 1/2 square foot per door. Ok, here, take a symbol hit it, then put a 1" square of butyl damper on the symbol anywhere, hit it again. Huge difference. Don't do the floor at all. They have asphaltic dampers already there. Actually, if you want to do wonders, take out the less effective asphalt by scraping it off, and put butyl dampers 3/4 the size of the asphalt. Then you'll lose weight and gain acoustic performance on the floor. Assuming the M3 has asphalt like the reg 3.
I wouldn't dampen the Front of dash. I like the engine noise. Actually i'd remove it all. Save it for the Lincolns!

[quality_sound]

Originally Posted by DiamondGCoupe

What about the wheel wells, there has to be some way to reduct tire/road noise aside from purchasing higher profile tires. Albeit much quitter than my previous car, there is still room for improvement. It's no 7-series but I shouldn't have to keep the windows down and blast the music just to avoid hearing the road.

Spray on undercoating works well for that. Dynamat has a spray that I've used that works weel but it didn't strike me as anything other than a normal undercoating.

[DiamondGCoupe]

What is a good quality undercoat spray I can buy?

[quality_sound]

They're all pretty much the same. I HIGHLY doubt you'll hear a difference from one to another. I will say this though, they work MUCH better than I thought they would and eliminate a ton of road noise.

[DiamondGCoupe]

Something like this:

http://www.dkhardware.com/product.aspx?product_ID=26559

I just want quality in a sense it lasts. Something is better than nothing and I just got the car so don't want to buy higher-profile tires now.

Also, does smoething like this require an adhesive spray before use?

[quality_sound]

Just hit up a local auto parts store and they'll have something. But they're all formulated with the adhesive so you simply clean the area, mask it off, spray it and let it dry.

[Synter]

If you want a superior quality and look's go with Line-X. Its a truck bed liner, it has numerous applications and it works fabulous. I had it sprayed in my trunk of my Evolution MR to reduce exterior noise and rattle from four twelve inch subwoofers. I've read numerous articles on this product, one was the pentagon uses it to line their walls due to it's sound deading properties. I was going to use dynamat but after reccomendations from other people that have used it I was sold.

Heres a good link to get you reading.

http://www2.line-x.com/ns/news.html?NewsID=191

[DiamondGCoupe]

I called a local dealer, they said they would have to take a look at the wheel wells but gave me an estimate of about $200. I can do it myself for much cheaper but this will probably last longer. Wonder if it dampens the sound the same a foam would? I think for $200 I'd give it a shot can't make it worse.

[quality_sound]

Foam won't do squat but WILL soak up a crap-ton of water and then get all nice and moldy. Just use the undercoating.

[roller]

Foam is only good if you want to stop a squeak or rattle between two surfaces that come in contact. Otherwise they really don't do much.