Sound Deadening Trunk
12-13-10, 03:03 PM
#31
i will say that you doing a decent job applying the sound deadening mat. however, if you are looking to drown out some of the exhaust noise you are going in the wrong direction.
the butyl based mats were not designed to be placed on panels with a lot of ridges and recesses, because these ridges and recesses help reduce the ability of the panel to vibrate. if you would choose to use butyl based mats on these areas, you only need to use a small amount. these mats are design to be used on large flat and unsupported panels like the outside door panel and the head liner, and even on these panels you do not need full coverage or layered amounts to get the desired effect.
what you need is some type of foam barrier to help reduce the sound. these foam barriers, just like fiberglass insulation in a house, are design to make the sound waves travel a greater distance. this is usually why thicker insulation will give better sound reduction. many of the products out there force you to use some type of adhesive to bond these foam barrier to the steel panel, but what i found out is that you can get some indsutrial strength velcro and velcro thicker foam/vinyl lined mats to the panel. this makes it great because there are no harmful fumes, and you can easily remove and reapply these foam barriers incase you need to get under them for maintance.
the butyl based mats were not designed to be placed on panels with a lot of ridges and recesses, because these ridges and recesses help reduce the ability of the panel to vibrate. if you would choose to use butyl based mats on these areas, you only need to use a small amount. these mats are design to be used on large flat and unsupported panels like the outside door panel and the head liner, and even on these panels you do not need full coverage or layered amounts to get the desired effect.
what you need is some type of foam barrier to help reduce the sound. these foam barriers, just like fiberglass insulation in a house, are design to make the sound waves travel a greater distance. this is usually why thicker insulation will give better sound reduction. many of the products out there force you to use some type of adhesive to bond these foam barrier to the steel panel, but what i found out is that you can get some indsutrial strength velcro and velcro thicker foam/vinyl lined mats to the panel. this makes it great because there are no harmful fumes, and you can easily remove and reapply these foam barriers incase you need to get under them for maintance.
I'm not sure how your post is useful at all, unless you can post links to the exact product you speak of and before and after statistics, rather than simply "what you've found".
Last edited by dsg03svt; 12-13-10 at 07:14 PM.
12-13-10, 06:54 PM
#32
Did you read his entire posts? He stated that he was looking for a slight increase in sound resonance in the cabin. He used B-quiet material, a product many use for this exact type of situation. He posted before and after results and stated he was satisfied with the outcome.
I'm not sure how your post is useful at all, unless you can post links to the exact product you speak of and before and after statistics, rather than simply "what you've found".
I'm not sure how your post is useful at all, unless you can post links to the exact product you speak of and before and after statistics, rather than simply "what you've found".
As for proof, here you go.
05 Ford Focus Zx3 with intake, exhaust without resonators and turbo.
All these numbers were read with a pressure level meter mounted from the passanger seat head rest.
Before
Idle 79db
25mph, 3rd gear 87 db
50mph, 5th gear 91 db
After First Install - Covered 50% of the following with second skin butyl mat. Outside door panel, outside rear fender panel, outside hatch panel, floor and 35% of the roof. Then covered 100% of outside door panel, outside rear fender panel, outside hatch panel, floor and roof with closed cell foam 1/8" thick.
Idel 77db
25mph, 3rd gear 86db
50mph, 5th gear 89db
After Redo - Ripped off all the closed cell foam and layed down a vinyl/foam barrier in its place. Then topped the barrier with closed cell foam. I did not add anymore butyl mat. Also covered the wheel wheels in foil backed foam, and the underside of the hood as well. Stuffed the shock towers, rear quarter panel openings, hatch door, and all the pills with fiberfill and foam blocks.
Idle 71db
25mph, 3rd gear 81db
50mph, 5th gear 83db
You can see by the results on the focus, that the foam/vinyl barrier had a greater effect on blocking out noise.
Infiniti g35, stock
Before
Idle 61db
25mph, 3rd gear 72db
50mph, 5th gear 75db
After-Only covered the entire floor of the vehicle with a vinyl/foam barrier.
Idle 57db
25mph, 3rd gear 66db
50mph, 5th gear 69db
For why I havent done anything with the lexus yet, is because I havent had time. For me to do it right, and strip the entire of the car lay everything out, and put everything back would take me about 2 days. I could do it quicker, but I am picky and it takes me longer to bag and label everything than anything else.
Lastly for products I have used, I have used sds, secondskin and some other stuff that was bought through a local stereo shop.
Last edited by archie; 12-13-10 at 10:18 PM.
12-14-10, 04:04 AM
#33
Archie,
Appreciate the comments, but as dsg03svt stated I was only looking to reduce the sound to a tolerable level and get rid of a few resonance issues while NOT adding much weight. From the outside of the car it sounds amazing so I really didn't want to change the sound by changing to a quieter muffler.
I did my research and discovered a hand full of people that used B-quiet material with success so I gave it a try myself with good results. I know there are ways to drastically reduce the sound in the car, but that would require a lot of additional weight and material. There seems to be a balancing act between performance and sound. One has to keep that in mind before adding significant weight with sound deadening material vs putting some quieter mufflers on. By taking the route I took, I feel like I fall right in the middle being happy with the sound (inside/out) and fine with the few additional lbs of added weight.
Appreciate the comments, but as dsg03svt stated I was only looking to reduce the sound to a tolerable level and get rid of a few resonance issues while NOT adding much weight. From the outside of the car it sounds amazing so I really didn't want to change the sound by changing to a quieter muffler.
I did my research and discovered a hand full of people that used B-quiet material with success so I gave it a try myself with good results. I know there are ways to drastically reduce the sound in the car, but that would require a lot of additional weight and material. There seems to be a balancing act between performance and sound. One has to keep that in mind before adding significant weight with sound deadening material vs putting some quieter mufflers on. By taking the route I took, I feel like I fall right in the middle being happy with the sound (inside/out) and fine with the few additional lbs of added weight.
Last edited by caymandive; 12-14-10 at 04:11 AM.
12-23-10, 04:19 PM
#34
No more annoying drone!
My drone is now nearly non-existant. The fix was some high flow cats that were just installed. I couldn't be happier especially since I lost no power in the process!
https://www.clublexus.com/forums/6015477-post187.html
https://www.clublexus.com/forums/6015477-post187.html
01-15-11, 11:21 AM
#35
^^^ Im about to have a sikky/Joe z set up installed on my F with random tech cats following in your footsteps with JE. I like being able to talk to people in the car and through bluetooth without problem, should i be considering the sound blocking mat? Joe, anymore word on silencers? What kind of power loss do you think silencers would add?
10-06-15, 08:11 AM
#36
I am going to revive a "dead" topic to see if anyone has tried anything new in the past 4.5 years. As with the OP here, I also like the sound outside of the car, but would love some reduction in the sound below 2k rpms around town. My car is currently equipped with a Borla cat-back exhaust. Has anyone achieved significant noise reduction without adding more than 10-15 pounds? I think I will start with the B-quiet pads because the OP said it reduced his drone and I am really struggling with it currently.
(edit) Well, I just saw a more recent post regarding eliminating drone but the conversation has already devolved because of how the OP was acting and I don't see that going anywhere. However, the post raised the topic of adding in cats or resonators to reduce the drone. Up front, I know nothing about how sound waves move through exhaust systems and even after reading the linked article, I am still not sure what will work in my situation. I would be grateful to learn what others have done to their cars to allow them to have passengers that don't complain or choose to ride in another car because of the noise.
(edit) Well, I just saw a more recent post regarding eliminating drone but the conversation has already devolved because of how the OP was acting and I don't see that going anywhere. However, the post raised the topic of adding in cats or resonators to reduce the drone. Up front, I know nothing about how sound waves move through exhaust systems and even after reading the linked article, I am still not sure what will work in my situation. I would be grateful to learn what others have done to their cars to allow them to have passengers that don't complain or choose to ride in another car because of the noise.
Last edited by Helo58; 10-06-15 at 08:23 AM.
10-06-15, 12:28 PM
#37
Lexus Fanatic
I did this in my G35 sedan. Dynamatted the trunk and back seats and it did jack squat. I always thought about putting some right above the muffler. It is what it is . Good luck
10-06-15, 01:25 PM
#38
Thanks for that information. Based on previous reading, I was pretty sure that the results would be minimal, but for a days work and 80 bucks, it seemed like it may have been worth it. What I have found so far leads to modifying the metal/components of the exhaust to change the resonance or use a thick foam (1") that is about a pound a square foot. I will keep searching. Thanks I8ABMR for the heads up.
10-06-15, 03:07 PM
#39
I used a cheaper alternative (fatmat) in my supra and wished I had never done it. The main reason is because its nearly impossible to remove without a mountain of effort and leaves a nasty tar residue behind. Also, it didn't make a lot of difference in my opinion.
If it were me I would add carpet padding like you see in your home. I added a couple layers in my supra's hatch and it made a big difference. All you have to do to remove it is pull it out.
If it were me I would add carpet padding like you see in your home. I added a couple layers in my supra's hatch and it made a big difference. All you have to do to remove it is pull it out.
10-06-15, 05:58 PM
#40
Lexus Fanatic
I had to deal with this in my heavily modded G35. All I got was added weight in the trunk. I would say it would be more effective to simply mod the exhaust.
10-07-15, 07:15 AM
#41
Thanks for all of the posts. I am convinced that the dynamat (& alternatives) will not solve the problem. Now I need to start researching exhaust mods/fixes. For some reason I think I remember someone posting that they added headers with high flow cats and that fixed the problem. If anyone has proven drone removal, please post solutions plus pics if you are willing!
B-Quiet has a product called "Vcomp" which is a thick foam/polymer composite that claims to reduce noise (not resonance) but it is 1lb per square foot. It will be interesting to see how much exhaust mods will weigh/cost in comparison.
B-Quiet has a product called "Vcomp" which is a thick foam/polymer composite that claims to reduce noise (not resonance) but it is 1lb per square foot. It will be interesting to see how much exhaust mods will weigh/cost in comparison.
Last edited by Helo58; 10-07-15 at 07:20 AM.
10-07-15, 09:53 AM
#42
Thanks for all of the posts. I am convinced that the dynamat (& alternatives) will not solve the problem. Now I need to start researching exhaust mods/fixes. For some reason I think I remember someone posting that they added headers with high flow cats and that fixed the problem. If anyone has proven drone removal, please post solutions plus pics if you are willing!
B-Quiet has a product called "Vcomp" which is a thick foam/polymer composite that claims to reduce noise (not resonance) but it is 1lb per square foot. It will be interesting to see how much exhaust mods will weigh/cost in comparison.
B-Quiet has a product called "Vcomp" which is a thick foam/polymer composite that claims to reduce noise (not resonance) but it is 1lb per square foot. It will be interesting to see how much exhaust mods will weigh/cost in comparison.
With already having an exhaust I would personally look at adding some cats. I've been seriously considering getting some Vibrant GESI High Output cats to avoid the exhaust swap each year for inspection purposes. http://www.summitracing.com/parts/vpe-7525
Last edited by caymandive; 10-07-15 at 10:15 AM.
10-07-15, 11:06 AM
#43
FWIW .... I've had the SIKKY headers combined with the Borla catback (catless) for a few years now and it's comfortable to me. When I had the SIKKY headers and JoeZ exhaust it was very uncomfortable. When I state comfortable i'm referring to the just under 2,000 rpm drone that most experience.
With already having an exhaust I would personally look at adding some cats. I've been seriously considering getting some Vibrant GESI High Output cats to avoid the exhaust swap each year for inspection purposes. http://www.summitracing.com/parts/vpe-7525
With already having an exhaust I would personally look at adding some cats. I've been seriously considering getting some Vibrant GESI High Output cats to avoid the exhaust swap each year for inspection purposes. http://www.summitracing.com/parts/vpe-7525
As for cheap, quick fixes... I have been doing a little more reading on other websites where guys have wrapped their exhaust pipes with header/exhaust tape with some success. Sounds sketchy to me though...
10-07-15, 11:43 AM
#44
To everyone who knows about 180 degree sound cancellation (Helmholtz), disregard this post. I am still learning. Apparently this is done, by calculation, where a pipe/chamber is wyed or tee'd off of the main exhaust branch (per side) to put low freq sound waves 180 degrees out of phase into the existing exhaust flow to cancel out the sound/drone.
With that being said, does anyone have any information related to length, diameter, and placement of Helmholtz resonators for our cars? Where is there suitable room underneath our cars for an approximately 2 foot long exhaust branch wyed off of the main branch on both sides.
With that being said, does anyone have any information related to length, diameter, and placement of Helmholtz resonators for our cars? Where is there suitable room underneath our cars for an approximately 2 foot long exhaust branch wyed off of the main branch on both sides.
03-22-17, 02:21 PM
#45
Lexus Champion
