Noise reduction stuff

[hwystr]

I know most of you are just trying to go faster, so this won't apply.

If anyone else is interested in reducing the damn road/tire/trans/exhaust noises in their car, I'm going to order a bunch of stuff from www.be-quiet.com ("Brown Bread" constrained layer mastic, "H-Liner" engine liner, "Vcomp" insulator w/barrier).

Looking to get a bigger order to get the prices to drop a bit.

Any interest => PM me.

 

[MidLifeC]

How about a post instead?

I am interested in this also, I just haven't decided how much I want to do. Maybe just the trunk and back seat? Anybody else have experience with this?

 

[postban]

It won't work man. NVH is my job. Air Flow is the secret to Road Noise past adding Asphaltic mats (deadening, no effect on air transferred noise). The SN95 chassis flows tons of air. I started designing parts for it in early '93 as we were sourced on the SN95 launch. Dozens of part deletes and directed cost saves later you have the noisy but fast cars we get today.

I have been present at CFM flow testing for coupes and verts alike at DAP. The mean average flow for the SN95 is 680 CFM of air. That is like the worst number possible, highest I know of actually. Air flow is tremendous around the door handles and license plate, like holding your hand up to a fan on high. It leaks at the door hinges, the dash, the package tray etc...
It is sad but true.

The SN95 uses far less NVH than most any other car Ford makes. No engineered baffles, just a few chunks of heat expanding foam.

Now another car we had control over, the Explorer is targetted below 150 CFM which my company surpassed. We had it so sealed they had to add a pressure bypass in the d-pillar so the doors would close instead of pop back open. Many stories there.

 

[MidLifeC]

I'm not looking to stop the overall cabin noise, I'm talking about an annoying drone from the back of the car - trunk or back seat area. Some other guys posted in the main forum about using the breadboard stuff and saying it worked to reduce the drone. It is a low frequency vibration accentuated by the H pipe. I was hoping a little insulation back there might change the harmonics?

If it doesn't get any better I'm gonna have to take off the H pipe.

 

[postban]

Originally posted by MidLifeC
...snip... I was hoping a little insulation back there might change the harmonics?

If it doesn't get any better I'm gonna have to take off the H pipe.

Well, at least you have it isolated to a certain components installation. Do you have the baffles in? That always lowered volume/drone in mine. I also wire wrapped the glass fiber stuff on the baffle for more reduction. Solid Copper wired wrapped spirally around the material binding it tightly to the baffle.

A guy I work with has an 01 GT and did undercoating/rustproofing and swears it made a huge difference:shrug:

 

[MidLifeC]

Baffles are wire wrapped and packed with fiberglass and installed. Taking them out is problematic which is one reason i didn't dyno on saturday.

As far as the undercoating idea, i think the breadboard stuff is the same idea only with better acoustic properties. I don't want any black tar shit on my car.

**edit**

Thanks for the ideas, i do appreciate the suggestions.

Does anyone have any acoustic measuring equipment?

 

[hwystr]

Hey postban - can you get me the prioritized list of leaks from DAP on current model vehicles ? I'm pretty familiar with NVH as well, and your right leaks are a main path for airborne noise and I'll plug all I can find. 680cfm is way too high, hell my doors barely close with the windows up. I suspect 680 is with the extractors open - they add ~400cfm.

MidLife - Post is OK, just tell me what you want. Go to www.be-quiet.com and see what you want, I'm hoping to get some takers on the brown bread to get the 70sq-ft pricing, need 1 taker for the H-liner to get the $49.99 pricing, I'm already buying 3 Vcomps, so $49.99 is the volume pricing.

I'm planning ~30sq-ft of mastic patches (not 100 like the sub-woofer crowd) - just to deaden the panels that get excited by low frequency stuff amplifying droan.

I'm doing the "H-Liner" (hi-temp insulator + barrier) over the trans - we did a similar "trans blanket" on Ranger and saw ~10% improvement in AI.

The "Vcomp" is an insulator/barrier I'm gonna put under the carpet, trunk, and doors to block & absorb the tire/road noise. It will block/absorb alot of the road/tire noise from both leaks as well as vibrating panels.

I thought about doing a before/after with some equipment, but its a royal hassle to do right.

 

[postban]

There is one mod you might do, shoot lots of guns and lose that annoying range of hearing causing you the trouble:kaboom: :lol1:

I did:loser:

 

[MidLifeC]

Postban: shot guns and worked in a stamping plant. My high range is gone, but I can still hear the lows.

Hwystr, I am not interested in the H-liner at this time.

I do want some brown bread to cover the trunk and back seat area, I'm not sure how much I need: any idea since you appear to know what you are doing?

Looks like the vcomp or lcomp goes on next to help with noise isolation. Again, I'm not sure how much I'd want: probably enough to cover the bottom of rear passenger and trunk area. It looks like lcomp has better acoustic properties than vcomp. Any reason you are going with vcomp?

Looks like we aren't too far away from each other.

 

[hwystr]

MidLife-

I took another look at the cobra, most panels are pretty dead, probably don't need more than 10-15 sq-ft of mastic. I was planning on 30, but that may be a bit much. Unless I get more takers, it will be ~$3/sqft - let me know how much you want.

The LComp costs 2x as much as VComp on a sq-ft basis, and only gives you 2-3db more reduction at the low frequencies. I just didn't think it was worth the extra dough... You could double up the VComp and get much better performance at the same price.

I suspect the VComp will make the biggest difference in the cabin noise, so I'll be going all out on it (50+ sqft). If you want you can wait and see how mine turns out before throwing $200 at it - I'm already at the volume pricing level.

 

[hwystr]

I gave the wrong URL for B-Quiet its: www.b-quiet.com.

Sorry if any of you were bashing your heads trying to figure out what i was talking about. :bash:

 

[MidLifeC]

hwystr,

I was already on their website trying to figure out what I wanted to do.

To summarize, we'll split some brown bread - I'll rely on you to detrmine the need (and suggest where it needs to go). It sounds like you might have some extra vcomp, which I'll be happy to take off your hands-just not sure how much I'd want.

Got my cell # from the membership list?

 

[hwystr]

Midlife - No problem, I'll probably order early next week (have some stuff going on right now) I'll let you know when it gets here and we can have a mod party. No idea we had a membership list w/phone numbers :shrug: where is it ?

Just PM or email me your number.