Blown_Red_97z

iTrader: (3)

Car has B&B catback with the resonator. At around 1100-2000 rpm the drone in the car is horrible. I think fuzzy said it was resonance in the spare tire wheel well.. Thinking about getting some peel n seal and doing inside the truck and maybe under the car. Thoughts? Anyone else have this problem?

FuzzyLog1c

iTrader: (4)

Place a layer of B-Quiet Ultimate, Dynamat, or an equivalent CLD (Constrained Layer Damper) in the spare tire well. Also recommend a layer under the back seat, and between two and three layers directly over the driveline into the trunk (use the hand test to figure out how many layers are necessary). But if you're on a budget, just the tub is sufficient.

This will eliminate the resonance of the tire tub, but it will not quiet the sound of the exhaust. There is a definite distinction. If you also want to quiet down the exhaust, you'll need to add a MLV (Mass Loaded Vinyl) on top of the CLD layer below the rear seat, in the seat back trunk lid, and completely treat the rear shelf of the car.

smokeshow

iTrader: (17)

I did a write-up on this a couple years ago. If you are absolutely sick of it and you're willing to modify your exhaust a bit, this will help.

http://www.performancetrucks.net/for...-drone-489463/

FuzzyLog1c

iTrader: (4)

That only works if the source of the drone is the exhaust. Naturally, every exhaust will have a resonance at at least one frequency (and the n-integer harmonics of that frequency or frequencies), but in this case, we basically have a thin-shelled metal drum inches between two pipes. The Corsa might have a nasty resonance, but unfortunately, so do our trunks.

By the way, I read your thread a year ago. Nice to see an engineering approach to a problem.

Blown_Red_97z

iTrader: (3)

I've been thinking about this and the resonance must be due to the frequency of the exhaust matching the natural frequency of the car, at least in the trunk which elevates the amplitude. So we gave to dampen it with the insulation.

What kills me is b&bs website that says they've done tons of testing and there is no drone. They're full of ****. They might have done it on a few cars but not every system they developed.

I've read that the peal n seal is the same as the cheaper dynomat. That's why I think I'm going that route

FuzzyLog1c

iTrader: (4)

You need to do more research. Peel and Seal is an asphalt-based roofing product. Dynamat and B-quiet Ultimate are butyl-based constrained load dampers. Go look at the transfer functions. There's no comparison when it comes to structureborne attenuation. Don't make your car heavier and have nothing to show for it.

DACTARI

iTrader: (1)

This is correct, and this is the solution. I did it on my V, and here is the write-up:

https://ls1tech.com/forums/cadillac-...ltz-tubes.html

Blown_Red_97z

iTrader: (3)

I have done research. The cheaper dyno mat is petroleum based. Same stuff as peal and seal. If you want to spend 3 times as much you can go against the petroleum based stuff. Some people say the peal n seal has a bad scent however most have never smelt this. Spend $100 on peal and seal or $300 on b quiet for the same amount. Btw I'm a PE ME so yes I do understand the engineering behind it. I'm also iso level 3 vibration analysts trained through TA of Charlotte so I understand the resonance issue.

Iceman_jd

I'm had bad drone albeit on a V6 but I did the peel and seal, rapped the exhaust to no avail.

The only solution that worked for me is following and implementing DACTARI's J-tube solution.



My V6 solution:

GXP25

iTrader: (3)

Do you have a link to those transfer functions? I'd be interested in seeing them.

54inches

iTrader: (4)

http://www.b-quiet.com/compare.html

FuzzyLog1c

iTrader: (4)

You can throw certifications at me all you want--I know more people with masters degrees that know less about a subject area than your average, interested high school student.

One of the things that you may be forgetting is that the viscosity of the fluid, its stability over a range of temperatures, and the composition (mostly, stiffness) of the sheet that provides the "constraint" part of the CLD formula are critical to the dampening performance of the product.

Bottom line: Peel and Seal is designed to waterproof roofs. B-Quiet Ultimate, Dynamat, and Damplifier Pro are designed to attenuate structureborne vibration. Do they all feature some kind of gooey substance constrained by a metalized sheet? Yes. But the similarities end there.

Iceman_jd

I agree insulating the (metal drum) trunk area will definitely help (it helped me) with external road noise, but not the drone. I used GTMAT still petroleum based but not exactly seal and peel.

Getting back to the source of the drone. If you didn't have a drone then you change something in your exhaust piping now you have a drone it's safe to say the change in the exhaust (piping/resonator/muffler, etc) is the cause.

To completely solve the problem you need to address the source of the drone not just try to cover it up. The resonating drone reverberates the whole length of the exhaust. That is why I believe no amount of quality soundproofing will eliminate the drone.

Plenty of people have exhaust systems and are drone free but if your unlucky enough to have purchased an exhaust that sucks and not willing to replace it I still say the J-Pipe solution is the way to go.

meatyCTS-V

Oh boy here we go, another my dick is bigger than yours thread with engineering bullshit...

07CTS-V

iTrader: (6)

B&B'S sent me exhaust cones to stop the drone free of charge. I never installed them, I just crack my cutouts and the drone is gone. They obviously know about the issue with first generation V's.

05CTSV

iTrader: (16)

I have to laugh every time I see a drone, or my exhaust is too loud post. Lets see it was quiet stock, headers and cat back....now it's too loud. Then don't put a performance exhaust on your car, keep it stock. It's not a news flash v8 motors tend to get louder with headers and aftermarket exhausts. I'd run open headers if the law allowed, love that sound at any rpm.

FuzzyLog1c

iTrader: (4)

The problem arises when people can't have a conversation in their car or listen to music. A drone in the 1750-2000 RPM range is especially obnoxious because most people probably spend 75% of their time driving there.

05CTSV

iTrader: (16)

Oh I get it. Easy way to solve it, tell passengers to shut their traps while you're driving and trying to enjoy the sound of your finely tuned maching. As for music, well that is being played by 8 cylinders beautifully at 1800 rpm .

I guess everyone has their own preferences. The drone is especially helpful when you don't want to have a conversation. Wife starts yapping about how much money you've spent on....blah blah blah, downshift and hit the sweet spot of serenity LOL!

sgtdestruction

iTrader: (1)

GXP25

iTrader: (3)

I don't see a single transfer function on that page.