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post #101 of 314 (permalink) Old 12-21-2010, 06:43 AM
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Psoup, thanks for cross referencing to those other products. Not just dynamat out there anymore!

As for whether the overall sound is improved or not, it is substantially improved. I believe the single biggest improvement, if you're doing to do one thing, is to cover the floor pan beneath the seats with damping sheet (I think all cars have some factory damping sheet on the footwell floor panels). Even if you don't put sound barrier down there to stop road noise from getting in, the idea is that the whole panel is resonating like a bass drum, *generating* lots of relatively low frequency noise.

Next I'd do the firewall, and then the doors.

It is definitely not as quiet in the configuration on which I settled above (basically damping sheet (Vmax) on the floor pans beneath the seats, damping sheet on the firewall, some damping sheet on the firewall trim piece, and some damping sheet and open-cell foam in the doors) as compared to having sound barrier (VB4) in the floor pans. However, I personally did not like how quiet it was with the latter, and the sound level now feels "just right" to my ear. Or maybe I just didn't like the sound of an extra 11.5 pounds.

As for weights, based on actually weighing pieces, I found:

Vmax 0.0028824 lbs/in^2
open-cell foam with damping layer 0.0040509 lbs/in^2

Lotus Sport Elise #24
71 TR6
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post #102 of 314 (permalink) Old 12-22-2010, 08:00 PM
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I was installing some of the sound dampener on my car this past week and I noticed that their is a hole on both sides of the car where the upper mount on the side grills slide into. They do not fully close the hole so I am sure this is a source for quite a bit of intake noise. I am going to find a way to close up the hole without impacting the mounting/removal of the side grills.
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post #103 of 314 (permalink) Old 12-22-2010, 09:06 PM
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Ok quick Q--

I have the touring pack on my Exige.

Where can I fit the MLV foam? I had put it everywhere but then I couldn't get the "speaker panel" back on... So I just removed everything...

This is what I did:

1) Removed the old touring foam from the firewall.
2) Added a sheet of damplified pro to the footwells.
3) Added a sheet of damplifier pro under the seats.
4) Added two layers (one on top of the other) over the whole firewall
5) Added a layer to the bare aluminum that protrudes from the lower firewall (where the velcro is)

I am 80% sure that my net weight is actually the same (nothing gained, nothing lost)... here are my specs:

Decibel readings BEFORE "mods":

Turn car on: 75
Cold idle: 66
Cold "hold" at 3k: 76
Cold "blip" to 3.5k: 87
Idle, 170 degrees: 61
Hold at 3k, 170 degrees: 76
Blip to 3.5k, 170 degrees: 86

Decibel readings AFTER "mods":

Turn car on: 75
Cold idle: 64
Cold "hold" at 3k: 75
Cold "blip" to 3.5k: 80
Idle, 170 degrees: 61
Hold at 3k, 170 degrees: 75
Blip to 3.5k, 170 degrees: 80

As you can see, it's a small improvement but about 5 decibels when it comes to "blipping"... so I assume that it will make driving a lot quieter. I was NOT able to get any info "at speed" because it was raining yesterday... but the "blip" improvement is very telling...

If I can find out where I can put the luxury liner pro, I think I can make a BIG difference!



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post #104 of 314 (permalink) Old 12-22-2010, 09:15 PM
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Quote:
Originally Posted by Ali.Maadelat View Post

I am 80% sure that my net weight is actually the same (nothing gained, nothing lost)... here are my specs:
Touring pack firewall foam is 5lbs if that helps.

Lotus Sport Elise #24
71 TR6
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post #105 of 314 (permalink) Old 12-22-2010, 09:23 PM
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The dampening material is to stop unwanted vibrations. It is going to make everything feel more solid and less tinny. It is not going to really lower the sound pressure very much. To do that, you will need to add some sort of a foam sound deadener.
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post #106 of 314 (permalink) Old 12-22-2010, 09:40 PM
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Quote:
Originally Posted by Fast Toys View Post
The dampening material is to stop unwanted vibrations. It is going to make everything feel more solid and less tinny. It is not going to really lower the sound pressure very much. To do that, you will need to add some sort of a foam sound deadener.
With those big, flat metal floor pans, I confirmed that much of the interior noise is coming from those resonating, so the damping sheet makes a pretty big difference on interior spl there.

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post #107 of 314 (permalink) Old 12-22-2010, 10:41 PM
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Any thoughts as to where I can fit the LLP foam in the car?



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2007 Lotus Exige S // 2009 Ferrari 430 Scuderia 16M // 2012 Chrysler 300C
2005 Maserati Gransport SOLD // 2006 Chrysler 300C R.I.P.
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post #108 of 314 (permalink) Old 12-23-2010, 05:51 AM
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I put it everywhere you see the damplifier in the pics I posted. I do admit I had to swear at the plastic cover extensively before it went back into place ;-) The passenger side was no problem but the drivers side was a b*&ch...

I first thought it was the extra foam blocks (cut out of the original touring pack foam) that were the culprit but moving them around didn't make any difference. If it wouldn't already have been late and I wouldn't have wanted to drive the car the next day, I probably would have used a borescope to see what the issue was...

Bottom line is that it will close and I'm not getting any more squeaks from the cover than before.
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post #109 of 314 (permalink) Old 12-23-2010, 04:50 PM
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Ali - did you get your measurements by being in your garage? I've noticed the concrete walls / floor in the garage causes the vehicle's sound to reverberate. Might be worthwhile to take another measurement outside in the driveway to make sure you are not compounding sound levels.
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post #110 of 314 (permalink) Old 12-23-2010, 09:11 PM Thread Starter
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Also remember that db is a log based scale. So every 2.8ish db is 1/2 intensity so a 6 db decrease, even though it sounds small, is less than 1/4 of the sound intensity.

2009 Saffron Yellow Elise Purist Edition - Unpurified (oem cupholder, leather tunnel cover, and black door panels), Difflow 5 element railer JR, Janspeed Stage II Exhaust, ongoing sound proofing project, kahtec blinking 3rd brake light.
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post #111 of 314 (permalink) Old 12-23-2010, 10:33 PM Thread Starter
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Originally Posted by Ali.Maadelat View Post
Any thoughts as to where I can fit the LLP foam in the car?
Ali, did you "cover" the panels with Damplifier or just 25% central coverage. Damplifier will dampen vibrations but is not great at blocking non vibrational sound transmission. That is the job of the LLP.

It is easy to fit LLP under the seats, on firewall behind seats, and beneath the plastic piece on the firewall (u may need to remove the OEM foam, I didn't have tge foam so I don't know how tight it will be to keep the foam). You can put it under the mats in the footwells, although I have not done this.

2009 Saffron Yellow Elise Purist Edition - Unpurified (oem cupholder, leather tunnel cover, and black door panels), Difflow 5 element railer JR, Janspeed Stage II Exhaust, ongoing sound proofing project, kahtec blinking 3rd brake light.
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post #112 of 314 (permalink) Old 12-25-2010, 08:28 AM
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Quote:
Originally Posted by psoup View Post
Also remember that db is a log based scale. So every 2.8ish db is 1/2 intensity so a 6 db decrease, even though it sounds small, is less than 1/4 of the sound intensity.
In terms of insulation effectiveness that's about right, but otherwise I don't think that's entirely accurate. Someone can check me for accuracy.

Measurements should be A weighted and
what you're referring to (intensity) is exactly half every -3dB but
Sound Pressure Level (SPL) halves every -6dB (and is more suited to our purposes) and
since we're primarily concerned with psychoacoustic loudness -10dB is a closer approximation to being half as loud.

Acoustic concerns with respect to hearing start at 70 dB
Hearing damage starts around 85 dB.

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post #113 of 314 (permalink) Old 12-30-2010, 10:50 PM Thread Starter
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Ali, did you ever get the LLP installed. That should be the workhorse in sound isolation....curious what numbers you got after it was all put together...

2009 Saffron Yellow Elise Purist Edition - Unpurified (oem cupholder, leather tunnel cover, and black door panels), Difflow 5 element railer JR, Janspeed Stage II Exhaust, ongoing sound proofing project, kahtec blinking 3rd brake light.
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post #114 of 314 (permalink) Old 01-07-2011, 04:20 AM
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Guys, thank you so much for your contribution of pics and references! Its a top class thread!

As I am a bit confused with all the materials and procedures used (being an elise and mechanic newbie!!), could someone please advice:

To achieve the most effective sound dampening, for the car to be as quiet as possible (not mind about the weight gain at all), which one of the previous reffered techniques and combination of products should I use?

Thank you and sorry for the 'stupid' question, but I am really confused!
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post #115 of 314 (permalink) Old 01-07-2011, 05:21 AM
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That's not a stupid question...

I believe for the least noise, you might want to follow my path (not too sparing on damplifier and generous with the luxury liner pro, everywhere you can get to).

I have been super busy at work and *still* haven't done the doors. I'd do those and make sure you adjust the windows while you have the panels off. I'm also contemplating the front wheel wells (using the same adhesive foam as for the doors).

Good luck and let us know how it goes.
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post #116 of 314 (permalink) Old 01-07-2011, 06:13 AM
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I realize this is slightly off topic, and sorry for long post, but as many of the people reading this EXCELLENT thread have experience in this general area, I'll raise this question here.

I've been struggling with wind noise from my hardtop ever since I put it on about 5-6 weeks ago. Only on the passenger side, and it starts at about 40 mph, getting progressively louder until it's screaming at 60 and above. I have adjusted the window height (it was way to high, riding well up above the gasket), adjusted the screws as far in as possible, so as to press the window against the gasket (it was clearly not even close at the back edge), and have played around with the front to back tilt a little. I have not yet moved the entire window forwards or backwards, though I note that the driver side is much further back than the passenger side, but the passenger side is already quite tight against the door top gasket.

This top was repainted, and they did an excellent paint job, and had removed and replaced the gaskets. I do note that the drivers side window seems to make better contact as it goes up and into the top gasket, whereas the passenger side seems to ride up onto the gasket, even after adjusting the height. There does not seem to be any adjustment to the top gasket, i.e., to move it outward, and it seems to fit onto a rail or extrusion that's part of the way the top is formed. The front and back seem to be pretty tight.

My next step is to continue to play with the tilt somewhat, and/or mask off different areas with tape and see if that makes a difference.

Any and all advice is appreciated. I have read all the threads on adjusting the window, but can't find a solution yet. The door lines up quite well, so adjusting the striker doesn't seem necessary, but I realize that even a tiny adjustment may be enough to make a difference, as I assume the issue is that the window likely bows out from the gasket frame as speed increases, so I may not be able to see/measure a gap while standing still. Thanks.

Still waiting for my interior parts, so I can pull the seats and install the vibration and noise suppression materials - but they tell me any day now!!

Last edited by Dylan; 01-07-2011 at 06:14 AM. Reason: fix typo
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post #117 of 314 (permalink) Old 01-07-2011, 06:40 AM
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psoup, thanks a lot for the door info. Sorry for the late reply. Somehow I never got a post notification...

I did a bunch of insulating two weeks ago but then was out of town again.

I started with the undertray and, while there, noticed that the diffusor is also prone to vibration. So I did both and the first pic shows where I put it. I was a bit concerned about exhaust heat, that's why I ended up with this pattern. No idea how valid that concern is, though. it's supposed to withstand 550F...

Next, I tackled the firewall. I put damplifier on all flat surfaces (2nd pic) and then covered them with Luxury liner. I cut the corner pieces off the original Touring pack foam and put only those back (in the big holes on the sides). Since I also upgraded the speakers at the same time, I also put some damplifier on the inside of the plastic firewall cover to preclude any rattles on that front.

Then I put both damplifier and luxury liner on the tank wall and the floor. That made the floor *much* more solid. I think there's a significant advantage of glueing down the luxury liner. Road noise is pretty much gone...

Since the liner is rather thick, I left some space (3rd pic) around the carpet buttons.
Zuspiel, thanks for your response! I will follow the same procedure as you, to eliminate as much noise as possible! If possible, I had 2 questions on your steps:

1) could you write analytically the exact ammounts of materials you used for the above procedure and the shops from which you bought them?

2) Did you glue the damplifier or the luxury liner on the car, or did you just place it on the needed places? if glued, how did you do it and can they be removed if needed??

Thank you!!
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post #118 of 314 (permalink) Old 01-07-2011, 07:30 AM
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1) could you write analytically the exact ammounts of materials you used for the above procedure and the shops from which you bought them?
I got 40 sq ft of damplifier but used less than half so far. I got more since we had already planned on doing my boss'es undertray and I have other things planned...

2 "sheets" of luxury liner pro ( 18 sq ft). Those are mostly gone. You definitively need more than one to do everything I did. I wasted a bit since I was a bit dyslexic on cutting two pieces (cut the mirror image...)

Also, make sure you have a roller and the right glue if you decide to glue the LL. Second Skin sells those, too.

Quote:
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2) Did you glue the damplifier or the luxury liner on the car, or did you just place it on the needed places? if glued, how did you do it and can they be removed if needed??
The damplifier is adhesive backed, so that always gets stuck on. It needs to have a good bond to work (use a wooden or rubber roller). It can be removed (once ) by peeling it off. I glued the Luxury liner to the damplifier with spray contact adhesive. From psoup's experience, that's not strictly necessary, but, as a friend remarked a while back, I'm an "anal little prick"

It also helps stiffen up the floor. I was surprised how much sturdier the floorpan felt after gluing the LL to the damplifier. I don't think you can remove the LL from the damplifier once glued since it's glued foam side down. But the whole sandwich should be removable (and will be trash once removed...)
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post #119 of 314 (permalink) Old 01-07-2011, 07:31 AM
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Great Thread and Great Question John!

Gentlemen, awesome thread - so very useful - I even bought a used standard exhaust as the Stage II drone was killing my wife on 4 hour drives to the mountains and the outer banks - as you can see by my pic - she sleeps as we had to yell the whole time and that wasn't fun - but I hated the sound of the standard exhaust and put the Stage II back on - this seems like the solution so,I am also very interested in this mod and would be very thankful to know:

Exactly what to buy?
How much to buy?
What approx will it cost?
Where to buy it from?
Where to stick it?

I am eager to get the 3500 rpm drone eliminated -

Thanks so much for everybody's effort

Best,

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MAJ, US Army
[email protected]
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post #120 of 314 (permalink) Old 01-07-2011, 07:40 AM
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Thanks!

I used Damplifier and Luxury Liner Pro, both from Second Skin (see psoup's post). Not cheap... (but worth it) Amounts are above.

BTW, doing the undertray and diffusor might help with the drone... (I have the std exhaust, so I can't tell...)
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