MY Drone noise can not be filtered by using sound damping materials
02-28-2013, 12:03 PM
#41
Advanced
Member Since: Feb 2013
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
You'd have much better results if you used the correct tools for the job.
Dynamat is used on panels to prevent or reduce panel vibration, which reduces some noise. It is not a sound deadener. If you want that, you need to use mass loaded vinyl, closed cell foam, or a combination.
Dynamat is used on panels to prevent or reduce panel vibration, which reduces some noise. It is not a sound deadener. If you want that, you need to use mass loaded vinyl, closed cell foam, or a combination.
02-28-2013, 12:27 PM
#42
Team Owner
Member Since: Sep 2000
Location: Far NW 'burbs of Chicago
Posts: 23,930
Received 2,047 Likes
on
1,359 Posts
St. Jude Donor '13
You'd have much better results if you used the correct tools for the job.
Dynamat is used on panels to prevent or reduce panel vibration, which reduces some noise. It is not a sound deadener. If you want that, you need to use mass loaded vinyl, closed cell foam, or a combination.
Dynamat is used on panels to prevent or reduce panel vibration, which reduces some noise. It is not a sound deadener. If you want that, you need to use mass loaded vinyl, closed cell foam, or a combination.
I'm thinking of trying to quiet the interior on our 2009, and want to use the correct material for each section. Stock NPP exhaust, so usually no drone.
Thanks.
02-28-2013, 12:39 PM
#43
Advanced
Member Since: Feb 2013
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
02-28-2013, 02:20 PM
#44
Pro
Thread Starter
You'd have much better results if you used the correct tools for the job.
Dynamat is used on panels to prevent or reduce panel vibration, which reduces some noise. It is not a sound deadener. If you want that, you need to use mass loaded vinyl, closed cell foam, or a combination.
Dynamat is used on panels to prevent or reduce panel vibration, which reduces some noise. It is not a sound deadener. If you want that, you need to use mass loaded vinyl, closed cell foam, or a combination.
My problem is my system had no mufflers. I was running straight pipe. The only thing to fix my drone problem would be parking the car with the engine off.
02-28-2013, 02:26 PM
#45
Safety Car
Member Since: Jan 2009
Location: Mooresville (Race City USA) NC
Posts: 4,681
Likes: 0
Received 2 Likes
on
2 Posts
Some suggestions for fixing exhaust drone:
One possible fix is to install thicker-walled tubes that run from the catalytic converter to the tail-pipe. This can help because thicker tube can have a much lower frequency than thinner tubes do. Many times, this means that thicker steel tube may also put on a little more weight, but it may be all you need to solve the problem.
Another fix is to shorten the exhaust pipe. This works because certain frequencies are generated by the length of the exhaust pipe. If it matches the frequency that is coming from the engine, then it generates the drone. So, shortening the pipe may not allow the frequencies to match up. With a dual exhaust system, shortening one of the pipes has also been known to help.
There are also some aftermarket resonators that you can attach to your exhaust system.
One possible fix is to install thicker-walled tubes that run from the catalytic converter to the tail-pipe. This can help because thicker tube can have a much lower frequency than thinner tubes do. Many times, this means that thicker steel tube may also put on a little more weight, but it may be all you need to solve the problem.
Another fix is to shorten the exhaust pipe. This works because certain frequencies are generated by the length of the exhaust pipe. If it matches the frequency that is coming from the engine, then it generates the drone. So, shortening the pipe may not allow the frequencies to match up. With a dual exhaust system, shortening one of the pipes has also been known to help.
There are also some aftermarket resonators that you can attach to your exhaust system.
02-28-2013, 07:41 PM
#46
Melting Slicks
Some suggestions for fixing exhaust drone:
One possible fix is to install thicker-walled tubes that run from the catalytic converter to the tail-pipe. This can help because thicker tube can have a much lower frequency than thinner tubes do. Many times, this means that thicker steel tube may also put on a little more weight, but it may be all you need to solve the problem.
Another fix is to shorten the exhaust pipe. This works because certain frequencies are generated by the length of the exhaust pipe. If it matches the frequency that is coming from the engine, then it generates the drone. So, shortening the pipe may not allow the frequencies to match up. With a dual exhaust system, shortening one of the pipes has also been known to help.
There are also some aftermarket resonators that you can attach to your exhaust system.
One possible fix is to install thicker-walled tubes that run from the catalytic converter to the tail-pipe. This can help because thicker tube can have a much lower frequency than thinner tubes do. Many times, this means that thicker steel tube may also put on a little more weight, but it may be all you need to solve the problem.
Another fix is to shorten the exhaust pipe. This works because certain frequencies are generated by the length of the exhaust pipe. If it matches the frequency that is coming from the engine, then it generates the drone. So, shortening the pipe may not allow the frequencies to match up. With a dual exhaust system, shortening one of the pipes has also been known to help.
There are also some aftermarket resonators that you can attach to your exhaust system.
02-28-2013, 08:49 PM
#48
Team Owner
Member Since: Sep 2000
Location: Far NW 'burbs of Chicago
Posts: 23,930
Received 2,047 Likes
on
1,359 Posts
St. Jude Donor '13
02-28-2013, 09:49 PM
#49
Safety Car
Member Since: Jan 2009
Location: Mooresville (Race City USA) NC
Posts: 4,681
Likes: 0
Received 2 Likes
on
2 Posts
What? That has to be the dumbest reply trying to sound smart. The OP's drone is caused by the fact he is running straight pipe. No mufflers at all. Easiest way to fix, cut off the straight pipe and install mufflers. Any mufflers. He can throw on a pair of Magnaflow 14336 and call it a day. $180-$200, problem solved.
02-28-2013, 10:35 PM
#50
Pro
Thread Starter
I kept my mouth shut and just let you guys talk but now you are starting to get personal. I have not said anything negative or personal about you. I do not need to be smart enough (REGARDING MUFFLER SYSTEMS) if I have the money to find out. Stop trying to tear people down. THe problem regarding my exhaust is resolved.
I will show you how smart I am by detaching myself from this post.
02-28-2013, 11:49 PM
#51
I kept my mouth shut and just let you guys talk but now you are starting to get personal. I have not said anything negative or personal about you. I do not need to be smart enough (REGARDING MUFFLER SYSTEMS) if I have the money to find out. Stop trying to tear people down. THe problem regarding my exhaust is resolved.
I will show you how smart I am by detaching myself from this post.
I will show you how smart I am by detaching myself from this post.
03-01-2013, 01:29 AM
#52
Intermediate
Member Since: Oct 2012
Location: Mountain View CA
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Reggied, sorry to hear about the crappy noise your experiencing. Here's my 2 cents... I often come across occupational noise exposure in my line of work and my first thought is your initial readings are not that bad. The "flat scale" low freq readings of 125Hz @102dB are equivalent to a modified measurement of 86dBA as compared to the OSHA Standard of 90 dBA noise exposure as an 8hr-time weighted average. However, the unwanted noise or drone is a nuisance! The only way to reduce the nuisance noise (aka, vibration) is apply treatment to: 1) source of the noise (exhaust pipe); OR 2) path of transmission between the source (exhaust pipe) & the hearer (you); OR 3) receiver (you). IMO, noise/vibration control products mentioned so far from previous replies are useful, but won't bring down levels significantly. Noise potentially can be reduced by 25% or up to 10dBA less. The practical approach should be to reinstall the muffler. And the least approach is to cruise around with earplugs, LOL. I agree when you mentioned that the entire car is resonating when on the road-this is the challenge! Good luck. -FC
03-03-2013, 07:23 PM
#53
Pro
Thread Starter
This morning I installed the OEM system..You are correct. These babbies are quiet. I will be drilling the 3/4 holes to bass it up just a little bit.
03-09-2013, 09:40 PM
#56
Team Owner
Member Since: Oct 2004
Location: San Clemente CA
Posts: 27,420
Likes: 0
Received 59 Likes
on
48 Posts
This weekend I drove from GA. to IL.
Newly purchased 2005 Corvette "Road Trip".
My improvements before trip
Peel & Seal, 3 layers in rear cabin, 1 layer on both wheel wells, and 1 layer behind both seat.
The rear cabin was loaded with 2 soft-shell-suitcases, and 3 thick winter coats. The Peel & Seal plus the suitcases and coats should be more than needed to damped my exhaust drove noise problems.
I used a Bruel & Kjaer Hand-held Analyzer Type 2250 (This device is used to measure sound levels at different frequencies in db)
At cruising speed of 70 to 80 mph I measured the following.
40Hz at 102db
125hz at 102db
40hz and 125hz are low frequencies. 96db in low freq in very loud.
I am getting readings of these freqs at 102db. THis is not GOOD to the body.
Frequencies this low can only be filtered by using a large solid mass that will not resonate.
Most filter materials used will only help with the higher frequencies and road noise. My corvette is like a giant sub-woofer mounted on rubber tires. Everything in the car is resonating at these freqs. Plus the shape of the rear window amplifies the effects
Some components of low freq can not be heard by the human ear but can still cause some damage to your ears if exposed too long. My car caused my "ear to jaw" to hurt after 6 hours of driving...I am only 49 year of age.
The exhaust system in my car is "engine to cats to resonators to straight pipe". TOO LOUD.
Solution for me....Going back to OEM.
Newly purchased 2005 Corvette "Road Trip".
My improvements before trip
Peel & Seal, 3 layers in rear cabin, 1 layer on both wheel wells, and 1 layer behind both seat.
The rear cabin was loaded with 2 soft-shell-suitcases, and 3 thick winter coats. The Peel & Seal plus the suitcases and coats should be more than needed to damped my exhaust drove noise problems.
I used a Bruel & Kjaer Hand-held Analyzer Type 2250 (This device is used to measure sound levels at different frequencies in db)
At cruising speed of 70 to 80 mph I measured the following.
40Hz at 102db
125hz at 102db
40hz and 125hz are low frequencies. 96db in low freq in very loud.
I am getting readings of these freqs at 102db. THis is not GOOD to the body.
Frequencies this low can only be filtered by using a large solid mass that will not resonate.
Most filter materials used will only help with the higher frequencies and road noise. My corvette is like a giant sub-woofer mounted on rubber tires. Everything in the car is resonating at these freqs. Plus the shape of the rear window amplifies the effects
Some components of low freq can not be heard by the human ear but can still cause some damage to your ears if exposed too long. My car caused my "ear to jaw" to hurt after 6 hours of driving...I am only 49 year of age.
The exhaust system in my car is "engine to cats to resonators to straight pipe". TOO LOUD.
Solution for me....Going back to OEM.
