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MG MGB Technical - Another option for Noise Reduction
|There have been several discussions about how to reduce noise in our Bs, and while searching for info on something else, I did turn up this interesting PDF file and info ~ http://www.quietsolution.com/QCar_dsheet_scn . I thought it might be of interest to some of you.|
|Also at the same site is this demo, http://www.quietcar.net/ for those who would like a graphic (audible) demonstration ~ http://www.quietcar.net/ FYI|
|Sounds good Bob. Perhaps you will report back once you have used it.|
|The easiest way to quiet an MGB, or any car for that matter, is to leave the wife at home...HA, HA, HA!........Oh, hi Hon.... want to go for a drive?|
|Once you have a decent exhaust muffler, it's not that easy to quiet a car. You have to know the relative noise source strengths and the paths that the noise takes to reach you. These can be different on different vehicles. I just want to caution against throwing proprietary noise control materials at the problem. Because of the way that decibels add ("logarithmically") and the ear's perception, you can often quiet one source and one noise path without any noticeable result. I speak from a lifetime in airplane and other noise control.|
Now, if someone has tackled your specific car before, and can point to specific noise treatments that worked, your chance of success is increased.
|You want to try a TR6 if you think a B is noisy!!|
|I won't be using it any time soon, but maybe someday. But I did figure the link might of interest to more folks than myself, perhaps those who haven't buttoned their cars up from restoration yet and can actually apply it beforehand. |
Here is another link more along the lines of a user report. Better than most amateur-on-the-internet reports: http://www.sounddeadenershowdown.com/ Perhaps there is something to be gained from from his insights into at least the usual-paradigm methods/products for treating this issue.
I drive a GT, so the possibilities that any of these treatments might have a noticable effect is probably greater than for roadster. Wind noise and exhaust noise (as pointed out) will always be an issue in cars as old-school and as small as ours. Today's cars have better methods of isolation than ours do, may have better engineering for the purpose than ours do, and by virtue of being as small as ours are and our proximity to the sources of noise, newer and somewhat larger cars probably fare abit better in relation to the inverse square law for losses between the ear and the source.
|My main aim when sticking in the sound deadening pads wasn't so much to make it quieter but to reduce the tinny rattling type noises. The car feels more solid I guess is the best way to describe it.|
|Gentlemen, I have sought the right combo of bang to buck products and technique to quiet the mgb roadster for years now. I have learned that 10 mil bitchethane ( known as Grace Ice Shield at Home Depot, 3' x 75' roll costs about 1 yard)rolls are the way to go. I use the 6 and 18 inch window flashing rolls for small piece in or pickup areas. Overlap 2 inches, roll heated and it is a bond forever! It works as well as Dynomat, but costs 1/5th as much. Use a heat gun and wallpaper roller to attach forever to prepared and coated ( Por-15, 2k epox primer, Rust Bullet or the like product, or plain old metal primer)floorpans, inner doors, wheel arches, inside splash box, behind and under dash, boot, and doors. I have found rolling the bitch onto the outer door skin complete, the sides and even the backside of the inner skin, then using a full sheet of the product as the moisture barrier, provides a muted thunk on door closure: Goodbye tinny sound rattle everytime the door slams. This is the most dramatic effort to make for sound deadening. Then, next on the bang-buck list is the cockpit envelope completed in the bitch, including sealing all firwall holes with silicone or latex caulk and the behind and under dash area. Use rubber backed floormat material under the carpet. I do both sides of the battery tray/boot wall, and the full boot inside including pushing up into the arches, inside wheel wells. This separates the road noise and muffler rumble from the inside. The effect is dramatic when the top is up. Third is the hood insulation. Just forget that stingy flop Moss sells in 2 pieces for the hood. I roll a layer of bitch ( hood must be taken off) over the inner surface cutting it wide and long and pushing it under the perimeter opening. Then I have discovered a product sold by the foot at Home Depot-an exterior floor mat product, heavy rubber back and stiff brush like front. Cut this big to fit under the perimeter and glue it on with 3M "Nashua" brand adhesive ( yes the expensive can-$16per). You will not believe the deadening effect of engine noise thereafter. Whole enchilada runs about a hundred to do a car. In a full roll the bitch left over will do a second car. Try it you'll like it. Be advised though, the effort takes about 8-10 hours, but can be done piecemeal. Cheers Vic|
|One question, Vem. How much does this stuff weigh? |
I work at HD and will have to take a look at these things in our store. Some asphaltum based products are HEAVY and I wonder about the floor matting you mention, too. These can be effective noise deadeners, just by density and weight, but may present too much weight gain for some folks interested in preserving or enhancing performance. That is, unless you've hopped up the ol' B-series or converted to a bigger mill.
Putting sheets or coatings of any noise deadening material on the whole surface of the insides of door and fender panels helps to kill the drumming of wind noise through the panels as well as the vibrations transmitted into them from the road and driveline vibrations. Some of our cars came with a small patch of deadener here and there, mostly, I am guessing, to kill a certain panel resonance. Great for the specific resonance, but not much good for other pitched noises being caused by vibration and/or transmitted through the panel. Probably one reason your efforts have been so effective, Vem ~ they simply kill more types of noise and vibration than the OE stuff ever was designed to and they cover a larger area.
I found the QuietSolution stuff interesting because of how it can be applied. Since it is not a sheet, you can put it anywhere you can get a brush. Many of the rattly noises come from misc parts, cables, wires, etc vibrating against each other, and to be able to coat an area where this occurs with a dampening coating might be worthwhile. I have noted that in some of the modern German cars (perhaps others now), they have taken to using a soft foam tape or tubing to wrap components (hoses, cables, wires) that rattle against stuff.
|Bob- Yep, it is heavy. Nuttin is free, but the effect afterall is so good, I've done all 3 cars, and plan on doin the MGA's if I ever get there. I'd guess you're adding 25 # if you do it all. When both sides are done, like on the tray or inner door skin, the muting is stunning, just too good. Vic|
|Here's another option for the uk folks|
That's taken from the Norwegian site, but you should be able to get it from [url]www.noisekiller.co.uk[/url]
UK bord memebers might even try this link
(I've no connection to either companies, but I have ordered 5 litres of Noisekiller to use in my 67 MGB GT)
This is a fascinating, if labour intensive, process which seems to produce very good results. Thank you for brining it to our attention.
Do you, or anyone else, know of any way to make a similar improvement to the wind noise of an MGB GT?
|P L Hills|
|Does anyone have more recent experience and/or recommendations on products like QuietCar or NoiseKiller since this thread ended back in '06?|
69 C in restoration
69 CGT awaiting restoration
|My experience is exactly the same as Vem's..I would never use the original-type floor stuff again...I coughed up the dough for dynamat because I didnt know about the other options, but its worth the money at any rate...not only does it cut down the noise but it also cut out the heat from the gearbox tunnel...my only advice is if you ever plan on painting your car...do that first...|
This thread was discussed between 05/04/2006 and 03/09/2009
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