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Discussion Starter #1
I just installed a MS3 stock muffler on my 2.5 hatch and although it sounds great at startup and highway speeds, the low drone at city speeds is a little louder than i want it to be. I'm thinking about doing some sound deadening in the back (where most of the sound is) but are there any other ideas?
 

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Put the old muffler back in :001_tongue:

No but if you want to do some sound deadening, it is quite expensive. Using a kit of fatmat or dynamat is probably what you'll need but it adds weight. When I first bought my MS3, it thought i was very loud compared to my buick but learned to love it.
 

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Discussion Starter #3
Put the old muffler back in :001_tongue:

No but if you want to do some sound deadening, it is quite expensive. Using a kit of fatmat or dynamat is probably what you'll need but it adds weight. When I first bought my MS3, it thought i was very loud compared to my buick but learned to love it.
Thanks for the advice. I'm gonna try some of that noise deadening in the cargo area but I'm not holding my breath.
I think you're right, I probably will get used to it and not even notice it soon. Do you think that some of the drone could be coming from the stock tips being about 1/2" shy of the end of the bumper? Maybe if the tips extended just to the end of the bumper then some of that resonance would b gone?
 

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um.... you should extend them ASAP, good way too burn your bumper and get exhaust fumes in the cabin...
 

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Discussion Starter #5
um.... you should extend them ASAP, good way too burn your bumper and get exhaust fumes in the cabin...
Did you read the original post? It's a hatchback w/ Oem ms3 exhaust. The muffler fits the same as it does on the speed.
Just wondering if lengthening it that small difference would reduce some of the resonance.
 

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Yes I read lol... but it shouldnt be short a 1/2".. that's a decent amount. And no that won't change the resonance. I think you will get used to it and listen to music or something should help. Speed3 exhaust isn't bad I've heard it in person. I want to see you with CS exhaust :)
 

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Discussion Starter #9
UPDATE: I bought some knock off dynamat stuff called Gt matt on amazon and I really wasn't expecting much but WOW!
it's not a night and day difference but there definitely is less cabin noise from the exhaust. I pulled out the hatch liner and spare+Bose sub and put down one layer. I ordered the 10'x1' roll and it was enough to cover most of the space. There is still a lot of empty space around the spare so I might get another roll or try some Roxul insulation and see how that works (I've heard good things).
Its really easy to see why the cabin can be so loud when you look at how little there really is between the trunk matt and the underside of your car. And there's such little insulation that it's like a hollow cave or a metal bass drum.
Anyways I'll keep you posted on the project as I do more. Hopefully this will be helpful to someone else looking to reduce cabin noise.
Wes
 

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How heavy is that 10' roll? So like 15' would cover the whole hatch floor?
 

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How heavy is that 10' roll? So like 15' would cover the whole hatch floor?
Yeah the 15 foot should be enough to completely cover the hatch floor. As for the weight I would guess around 2 pounds for the 10 foot. Its pretty thin so you could double up if you wanted.
 

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Update: rather than buy loads more gtmat, i decided to try out Roxul wall insulation. I read on a Toyota Matrix forum that a guy uses this stuff to great effect.
I used the styrofoam piece that surrounds the spare and cut the Roxul in that shape using a serrated knife.
Took it for a drive and this time the difference was night and day. I would say about 90% of drone was gone and the cabin is so much quieter overall with some real insulation in the back.
The stuff I used is called Roxul R16- the 3inch thick variety.
One word of advice to anyone planning on doing this. You might want to wear gloves or a long sleeve shirt because you will get tiny particles of mineral all over you and it will irritate your skin.
 

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I found when I installed mine the drone mostly went away after about 3-4 weeks. The computer adjusted the exhaust flow and after that I only noticed drone on highway speed above 105km. If you have a SRI/CAI that wont help either lol. Turn your music up or go back to stock. also if you put on a bigger exhaust pipe all the way back to manifold it will help with drone as well but it will be loud a F%$K
 
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