Reducing cabin noise
02-16-2005, 12:32 PM
#1
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Reducing cabin noise
What works best to reduce unwanted cabin noise?
This may be from vibration, wind noise, tires, exhaust, rumble, sqeaks, rattles, etc..
Please post here the sources of such noise, and how you've reduced it.
This may be from vibration, wind noise, tires, exhaust, rumble, sqeaks, rattles, etc..
Please post here the sources of such noise, and how you've reduced it.
02-16-2005, 01:40 PM
#2
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High frequency noises (turbo, alternator, belts...) come through small places. Thus plugging holes or isolating the firewall is the best bet for those. Low frequency noises are carried through structures as a result of natural frequencies and vibrations. As a result there is not too much you can do to isolate those except increase mass and isolation through products such as dynamat.
As for interior squeeks/rattles make sure everything that can move or rub it tight and at the places where parts contact make sure there is an isolator between the parts (felt sticky tape avalible through McMaster Carr)
NVH (Noise Vibration and Harshness) is highly time consuming and takes a lot of experience. good luck
As for interior squeeks/rattles make sure everything that can move or rub it tight and at the places where parts contact make sure there is an isolator between the parts (felt sticky tape avalible through McMaster Carr)
NVH (Noise Vibration and Harshness) is highly time consuming and takes a lot of experience. good luck
02-16-2005, 01:41 PM
#3
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I've found both the 951s I've had to be very reasonable in the noise level. The biggest noise that I had with both was squeking/rattling from the rear hatch. On the 88 it was so bad when I bought it that it literaly sounded like the whole rear end was coming loose. Fortunately, I already knew the solution: white lithium grease. Spray a little of this on both the rear hatch pins and down in the holes and the noise went away completely. Car now has zero rattles/squeeks. It aslo did have a little wind noise on the driver's side as well, but that was easily resolved by adjusting the fit of the door (had to do that on the 86 I had also).
One other big culprit to noise on cars in general are the tires. I've had some tires that were so noisy it sounded like I was driving a 4x4 with mudders. I just changed the 1/2 worn Kumho 712s on my 88 to Toyo RA-1s and the Toyos are actually noticeably quieter. The Kumho's weren't really loud, but it was definitely enough of a difference to be noticeable the first drive with the new tires.
Of course, another easy way to fix squeeks/rattles is to retighten everything. Tighten all the screws you can find and check all the trim pieces to make sure they aren't loose. Over time screws will work themselves loose and this can cause parts to have enough room to vibrate or rub against other parts.
One other big culprit to noise on cars in general are the tires. I've had some tires that were so noisy it sounded like I was driving a 4x4 with mudders. I just changed the 1/2 worn Kumho 712s on my 88 to Toyo RA-1s and the Toyos are actually noticeably quieter. The Kumho's weren't really loud, but it was definitely enough of a difference to be noticeable the first drive with the new tires.
Of course, another easy way to fix squeeks/rattles is to retighten everything. Tighten all the screws you can find and check all the trim pieces to make sure they aren't loose. Over time screws will work themselves loose and this can cause parts to have enough room to vibrate or rub against other parts.
02-16-2005, 03:59 PM
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My noise issue is with my newly installed 3-inch exhaust with a high flow catalytic converter (from the down pipe back). It is so loud that carrying on a conversation on the cell is close to impossible (not necessarily a bad thing when it’s the significant other demanding money). Initially, I thought I made a big mistake until going WOT. As usual the extra power generated and the earlier spool up time is addicting (puff) I am now purchasing Dynamat from Summit Racing. It’s a pliable sheet of sound proofing material (.070) thick (13 sq. ft $59.95, 39sq ft $169.95)
02-16-2005, 05:29 PM
#7
Rennlist Member
Originally Posted by Daddio
What works best to reduce unwanted cabin noise?
This may be from vibration, wind noise, tires, exhaust, rumble, sqeaks, rattles, etc..
Please post here the sources of such noise, and how you've reduced it.
This may be from vibration, wind noise, tires, exhaust, rumble, sqeaks, rattles, etc..
Please post here the sources of such noise, and how you've reduced it.
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02-16-2005, 08:47 PM
#8
if the foam cube is missing...how hard is it to put it back? can you squeeze it past the torque tube, or is it a drop the lot kind of operation again 
?
what is the extra noise like? reason i ask is that my car seems a lot noisier after the shop did my clutch install, but it sounds mostly like exhaust noise. i need to check whether that cube is missing i suppose.
?what is the extra noise like? reason i ask is that my car seems a lot noisier after the shop did my clutch install, but it sounds mostly like exhaust noise. i need to check whether that cube is missing i suppose.
02-16-2005, 08:58 PM
#9
Rennlist Member
I think you can stuff it in from the top. I also considered stuffing a towel in the cavaty between the shifter/TT/body. Still havn't messed with it yet.
