thetz99

I recently got a set of Okole seatcovers which I had to pull the seats out to put on, so I decided to finalize my soundproofing of the cabin to kill the drone of my resonator-lacking magnaflows.
After pulling back the carpet I put down a layer of dynamat and then 3 coated quietcoat over it. I covered from the crossbeam just in front of the seats/transaxle tunnel back to behind the seats. The dynamat will allow you to pull off the coating if you don't like the results.

Doing the passenger side (easily will take 1 full day of application/drying), you will see that the cat/exhaust "hump" protrudes into the pan. If you tap the metal over the hump it will sound hollow like a drum (the metal here is thinner because of the form for the exhaust path. After the dynamat/quietcoat, when you tap on it there is no resonance. Honda puts a dynamat type layer/with silver backing(poor heat shield) on the transaxle tunnel; I coated over that as well.
I drove around for a week before I finished up the driver's side next. The passenger side was the bigger impact of the two separate coatings.

The difference in the drone was immediate after the passenger side alone. It was like I had an earplug on my right side, it was that quiet. Just the sound of wind, engine and exhaust from behind.

My magnaflows sound like tuning forks now. It is beautiful to hear. And now the sound is ALL behind me and not sitting in my lap.


EDIT: I have moved on in my quest for drone suppression and have coated the exhaust pipe itself to 1. kill the drone at the source 2. cut the heating of the center console 3. Increase exhaust flow efficiency in this thread

https://www.s2ki.com/forums/index.php?showtopic=343230


Used what I learned heatwrapping the magnaflows and got an Invidia that I wrapped. What a GREAT sounding exhaust and no DRONE

https://www.s2ki.com/forums/index.php?showtopic=414220

sebrings2k

how much weight have you added in the process?

thetz99

When measured with a lighter exhaust, I have a net savings of 19 lbs.

It cracks me up when people bring up the weight issue.

I am 180 soaking wet. A gallon of quietcoat is 20 lbs wet, probably dries to 1/3 of wet weight. I used 2/3 of a gallon for under the carpets and under the car. A full sheet (32 inches x 54 inches) of dynamat probably wieghs 5 lbs (http://www.partsexpress.com/pe/showd...number=268-020). I used about 2.5 sheets for trunk/undercar/undercarpets. I did NOT quietcoat the trunk/tray area, only dynamat.


So for my installation the breakdown is
5 lbs quietcoat (dry)
15 lbs dynamat
which is 20 lbs.

On reflection, I did replace the stock mufflers and resonator-ectomy. The mufflers are about 20 lbs each and the resonator was about 15 lbs. The magnaflows only weigh about 8 lbs each. So I saved about 39 lbs on the muffler swap for a net savings of about 19 (39-20)lbs for a great sounding exhaust.

romduck

Where did you buy the Dynamat? I can only find some of the small sheets from my local car audio shop.

I like the idea of laying the quietcote (I have 1 gal) OVER the Dynamat. I am not as concerned about the weight gain (I'll slim my own ass down or date a lighter girl) as I am about queting down the car.

Any value in doing the inside of the doors? I'm also putting in a new sound system so I am thinking about hitting the doors at some point also.

I would have thought that all the road noise comes through the rag-top, but these threads have edumacated me.

THanks all.

thetz99

Here is the part # for the dynamat. Shipping is a bitch....

http://www.partsexpress.com/pe/showdetl.cf...tnumber=268-020

romduck

Thanks. That ws a huge help. I placed the order and the shipping IS a killer. Also, they are currently out of stock, but this should make a difference when it finally comes in. Thanks again.

deanjones

Careful! That 20lbs is going to make you lose .008 HP and your gas mileage is going to go down by at least .0009!!!

thetz99

I really enjoy the final mod for quieting the drone of my magnaflows. This all started because I first upgraded my stereo system, was happy with that result and then spoilt it all when I cut out the mufflers and replaced them with magnaflows which overpowered the stereo at all sound levels... I had basically lost my investment in my stereo.

I was pretty methodical in my approach. I started in the back and worked forward. Since I have gone through the process, I will rank according to IMPACT on DRONE the areas you should start with.


1. Under the passenger seat!! When you pull the carpet back here you will see all the noise sources that flood the cockpit.

2. Tray area/top of fuel tank/top of rear fenderwells under the soft top. Pay attention especially to the SPARETIRE area. You can tap here and hear the thin metal here, If you look underneath you have the differetial and the exhaust Y,

2a. Under the center armrest/parking brake area/parking brake adjuster

3. Under the car, passenger side, which includes the resonater area and transaxel tunnel.

3.5 In front of rear struts in wheelwell, and above mufflers (cover the hole in the framebeams!)

4. Under the drivers seat. carpetside and underneath the car.

5. In front of the rear wheels is the soft top drainage areas, all bare metal here.

6. trunk area... As logical that this area is a sound producer, do this test. Go on a long trip and stuff your trunk with clothes and baggage. It doesn't affect the drone at all. Doing this one first really disheartened me because I didn't get the results I was looking for.


Even though the thought of pulling a seat and then the rugs is a project, it really isn't that hard. Four easy to pull bolts on the seats (which is why they get stolen so easily) and then pull the rug from back toward the dash. There are about 8 clips of importance for the rug and you really don't have to pull it out of the car, just improvise something to keep it off the quietcoat as it dries.

I have my sound system back and I still enjoy the sound of my car!

visser

Perfect timing on the interior, as I'm getting ready to apply quietcoat to it this weekend! Glad to know it's going to make a difference there.

But I disagree on the trunk area. I applied three coats there last weekend, including over the fuel tank, and noticed an improvement overall (I had already addressed under the car, in the tranny tunnel and over the reslonator; but it did further reduce droning). This included applying it to the inner fender walls, as far as I could reach over the wheel humps.

I don't think the clothes test is the best comparison because, without addressing the vibration of the metal as well as quietcoat does, the clothes alone aren't as effective. Appyling quietcoat allows you to get every surfce, but packing clothes is bound to leave unaddressed areas. Just a guess.

And I don't have the directions in front of me to confirm it, but I recall it said a gallon dries to around 8 lbs.

tritium_pie

how much of a pain is it pulling up the carpet? any special tools needed?

edit: nm, I saw the posting regarding how easy it is to lift the carpet. thx.