Sound Deadening
 

Been trying to quiet down the exhaust note in the car. Took the entire trunk apart and notice a black square on each side. The square has some thin rubber that can move and open to let air in or out and is pretty much exposed to the outside. So exhaust noise can come right in and echo through the trunk. I covered these squares loosely with some ensolite. Anyone else try this. I am in the middle so I have not tested it yet. Plan on getting some more acoustic foam and jam it in there between the square and the side cover for the trunk.

Well, it's an effort. But you'll have better gains with any automotive sound deading matts. Just line the whole trunk and enjoy the less noise. But... the price is the factor.


The second thing you could do is go back to stock exhaust (assuming you have an aftermarket fart can)

Sound deadening will add weight. The goal of the car being lightweight is why there isn't much sound deadening from the factory. Add some if you want, but more weight equals less performance.

Here inlays the owners goals.
Would you really care if you add 10lb of more comfort, or would the extra 10lbs be a matter of winning or losing a race?

I'm pretty sure that if your that anal about extra weight in this car vs performance, you really bought the wrong car.

You can cover those vents with lead and you're not going to change what you hear in the cabin. I've been down this road... if you want to tame the exhaust, change the exhaust. Most of the volume is ultimately controlled by the muffler. What is your exhaust setup?

If you want to approach it from a sound deadening standpoint and change what you hear in the cabin, start here: https://www.sounddeadenershowdown.com . Learn about what these materials do and don't do and how to use them effectively. Even with a full sound deadening treatment (which I have done to my BRZ), the choice of exhaust components plays a huge role in what you will hear inside, tone and volume wise.

JDL uel header - Invidia Q300 - plenty of drone at low rpm. Love it when I am on it, but after an hour in the car it starts to wear on you. Just trying to tone it down a little. Some dynamite and ensolite and some acoustic foam should help. Been through this with my 04 WRX at stage 2 with prodrive muffler- it worked for that car.

Other than stock, the Q300 is probably as quiet a muffler as you can get but I thought I read that they can tend to get louder over time??? Put the stock muffler and mid pipe back on (if you still have it) and see if things change for you. I just don't think you'll get much out of blocking up those 2 specific spots.

At one time I had just a Tomei UEL...everything else stock + a full sound deadening treatment (front to back, side to side, roof, etc) and it was peaceful! Bluetooth conversations all day! I could only hear the header when I got on it, but that's it.

I will update when I am done. If I can just get a little quieter it will do.

Update: Only a little bit quieter for a lot of ensolite and dynamat. Seems my car is quiet on level ground or downhill but loud going up hill where any load is on the engine. I can get a deep loud base sound at like 2200 rpm going uphill. I think I got a loud Q300.

Please tell us that you already either plugged or removed the sound generator in the passenger foot well of the cabin.

Done awhile ago. All the noise is from the rear of the car.

I'm sure some of what you're hearing is coming right from the header itself. When I was stock exhaust with only the UEL Tomei header, I heard the header in the cabin when I got on it, even with full sound deadening.

The point of those flaps is evacuating cabin air to draw fresh air in. Plugging them means you don't get the same air flow.

If you remove the large plastic interior piece on the sides of the rear seats you will see that the entire car is open to the environment via drain channels that run along the side of the unibody. I took a very thin sheet of aluminum, put some raamat on the back and covered the front in Ensolite and sealed that opening with it. The same airspace goes into the trunk via the fenders. I sealed that with sprayfoam where the peak of the wheel is. Lining the flimsy rear covers with 2" thick batting from Michaels helps as well. Also, make sure the underside of the top of the trunk area and rear deck is covered in Ensolite.

Many Toybaru drivers want More noise than less. Perhaps they went to too many rock concerts and suffer from hearing loss, or perhaps they are bored by their spouses and need some other outlet for their frustration? Never mind.

Some Toybaru drivers prefer less noise, so they can concentrate on the driving with less fatigue. I am one of these, and my hearing is relatively well preserved for my age.

ACE makes an after-cat exhaust that is:

(a) lighter than stock;
(b) quieter than stock; and
(c) less restrictive than stock.

See : http://www.aceheader.com/index.php/p...-system-detail

There are also several threads here, including:

http://www.ft86club.com/forums/showthread.php?t=116707

If you want to reduce noise by getting a quieter exhaust, this may fit your requirement.