The age old problem: too much noise/vibration

[Insidious Surmiser]

So, I plan on dynamating the hatch of my car, and I thought I'd ask and see if that will be enough, or should I pull the carpet and do the whole damn car?

As usual, I get a nice exhaust on my car, and it's just too loud. Sounds great, but the reverberation is too much, it's rattling the car apart. Luckily, I won't be using this chassis. I have a hardtop I'll be using, and I don't want the same thing to happen to it.

So, what's the advice guys? Mat the hatch, or the whole floor?

 

[Prism11]

I would say the whole car. Doing the hatch will stop the noise from the mufflers, but the noise will travel to the next closest area to come in. And for what dynamat cost, the difference in price from enough to do the hatch to enough for the whole car is not that much. Plus you could get rid of the old asphalt deadening that is probably hiding some rust with the age of these cars now. I know I've found plenty in the seams, even with a relatively "rust free" shell.

 

[IndigoMKII]

If you're going to do it, do the whole car.

It will help some with the drone and vibrating, what exhaust are you running? My DM full exhaust is pretty cheap and doesn't rattle my car apart at cruising speeds.

 

[Insidious Surmiser]

I'm running a vibrant resonator maybe 8" casing 3" ID w/ a magnaflow racing muffler 3" ID w/ 12x4" casing. I think I should've gotten a bigger casing on the muffler 5" or something.

Anyhow, I think I'll do the hatch first, and tackle the rest shortly there-after. I don't have the tools or any experience to fix rust. But it should be no issue getting it done right. Just a matter of time and $$. Both of which I have enough of to do something simple like that. Definitely will get rid of that factory sound deadening.

 

[supraguy@aol]

I actually thought that the oem deadening material looked quite impressive- 3-layer, asphalt/jute/ashphalt...considering it was made in the 80's...
I will be replacing mine, but only because i had to fix some metal underneath.

 

[Insidious Surmiser]

It does do a pretty good job, but not up to the task. AND heavy.

 

[IndigoMKII]

Anyone know the actual numbers for before/after for the sound deadening material removed?

 

[Justin]

If you're going to go through the effort make sure you do your research on the product. Dynamat is designed to reduce vibrations, there are significantly better products for a hell of a lot less $$ that are designed to reduce noise. Search around the car audio forums.

 

[Insidious Surmiser]

Will do. Thanks Justin

Vibration is the main concern though, but I'll definitely do my homework.

good reading here thus far. http://www.sounddeadenershowdown.com/

 

[Poodles]

So you got an exhaust to go faster. So you're going to add weight to quiet it down which will slow you down...

This is all easily fixed with a proper exhaust setup, but what do I know...

FYI: I don't care if you coat every square inch of the interior metal on the car with dynamat, IT'S STILL GOING TO DRONE! The only fix is a properly tuned exhaust, as there isn't jack you can do about the glass and a drone is a harmonic.

 

[Insidious Surmiser]

lmao. I actually had an exhaust made to get better gas mileage, but you're not telepathic. You ought to see it though, there's hardly a bend in it.

You're right about the glass though.

In any case, I think that applying some vibration dampener to the panels will be enough. If not, plan B. (get a different muffler)

BTW coating panels with vibration dampener is completely pointless. It's not a barrier. 25% coverage is all you want, and no I won't be using dynamat. By the time I remove the factory deadener and install what I have in mind I will have lost wieght. Even if I go back and install a sound barrier. I will still have lost weight.

 

[MarkIII4Me]

I'll just leave this here.

http://www.supramania.com/forums/showthread.php?98641-Operation-quot-Can-t-hear-shit-quot-*Pics*

 

[Prism11]

Anyone know the actual numbers for before/after for the sound deadening material removed?

Im actually going to weigh the sound deadening that I remove (all of it), I wont have a chassis weight, but you could get a rough idea based on how much is taken off.

 

[IndigoMKII]

Im actually going to weigh the sound deadening that I remove (all of it), I wont have a chassis weight, but you could get a rough idea based on how much is taken off.

Awesome, if you could get those numbers that would be interesting to see how much weight could be removed from the interior while still not sounding like a hollow race car. With the sound deadening material removed and newer put back in with the front seats switched to 'racing' bucket seats. I wonder if that's close to 500 lbs lost..

 

[Insidious Surmiser]

I'll just leave this here.

http://www.supramania.com/forums/showthread.php?98641-Operation-quot-Can-t-hear-shit-quot-*Pics*

Let me state again, that noise level is of NO concern to me.

Trying to load the second page of your thread froze my computer. (my settings are for max posts per page) I didn't see that you used any vibration dampener (like I already stated that I intend to use)... unless the product you used was a combo sound deadener/vibration dampener. Anyhow, this is what I'll be using initially. Hopefully this will do what I want it to.

http://www.sounddeadenershowdown.com/sites/default/files/media/images/undamped.jpg
http://www.sounddeadenershowdown.com/sites/default/files/media_unit/sound/undamped.wav


http://www.sounddeadenershowdown.com/sites/default/files/media/images/damped.jpg
http://www.sounddeadenershowdown.com/sites/default/files/media_unit/sound/damped.wav

 

[MarkIII4Me]

I did notice a decent amount of vibration reduction after the secondskin was applied. This could be due to me applying it to both the interior and undercarriage. You will probably have better results with asphalt based mat due to its mass if only applying to interior. However, you can't beat the water based product if weight savings is a concern and ease of application.

And you may want to look into upgrading your computer if my thread locked yours up. Even my cell phone has no issues loading maximum posts per page. Do you run a first-gen celeron on dial-up or something?

 

[Insidious Surmiser]

lmao. It's a pentium 4. If I had celeron I'd be fucked. I think the amount of content + the fast download speed was a bit too much. Almost never have an issue with it.

If I go the sound deadening route, I will have already isolated vibration in the panels. Mass loaded vinyl is 1lb per square foot @ 1/10 inch, and that's what I plan on using. Not too heavy, not thick, not expensive. Only advice is to be wary of the smell. I'm assuming it varies from product to product, but something to keep in mind as some of the products are unbearable for this application.

 

[DeMoN2318]

Awesome, if you could get those numbers that would be interesting to see how much weight could be removed from the interior while still not sounding like a hollow race car. With the sound deadening material removed and newer put back in with the front seats switched to 'racing' bucket seats. I wonder if that's close to 500 lbs lost..

No way its gonna be 500 lbs!! The stock deadening material is on the order of 50lbs and the front seats maybe 100lbs total...



I just DynaMatted my whole car and I did not notice much of a difference with noise or vibration...

 

[IndigoMKII]

No way its gonna be 500 lbs!! The stock deadening material is on the order of 50lbs and the front seats maybe 100lbs total...



I just DynaMatted my whole car and I did not notice much of a difference with noise or vibration...

Hey, a guy can dream can't he? I thought the driver seat alone was close to 100 lbs and the passenger close to 70 lbs. Some threads say that the stock deadening stuff is close to 60 lbs with it all removed.

Okay so maybe it's not 500 lbs but shaving 100 lbs is always nice.

 

[DeMoN2318]

http://www.supramania.com/forums/showthread.php?159312-MKIII-A70-weight-index