I have finally got around to doing something about that point of entry for tyre noise at the rear arch. I had a good look at that rubber "mud flap". It is fastened forward to the underside bodywork. It was not sealing well against the metal & I figured wind noise was getting in so I sealed along the edge with silicone rubber and also did a hole higher up around a seam where 2 metal panels join. I did both sides of the car.
The result: tyre noise reduction very little BUT the growl of the exhaust/engine note is much reduced, which surprised me. I rather liked that sound so may unplug the sound tube.

I will seal further inboard from the seam later. I will also seal in the arch where the rubber meets the plastic and up around the rim of the arch where the rubber meets it. You can poke a finger between the arch and rubber and into the hole. I have left the small hole at the lowest point as I think it wise to let any water drain. I would not put any Thinsulate in the hole as it could get wet and encourage rust/mould.

After that I will check the front arches. I can feed at least 30cm of wire towards the back of the car via the hole at the lowest point. Is it sealed off beyond that distance?
What must be happening driving in the rain??

I have now sealed all around the rubber cover, leaving only a 3mm drainage hole at the lowest point.
The result is an incremental reduction in tyre roar and road rumble. Subtle but noticeable improvement. This is around town at 60kph so we hope to
notice even more improvement at higher speeds. Offsetting this is a slight higher pitched tyre or road noise that must have been there before is now revealed.
I reckon it could be dampened somehow. Maybe sealing all around the arches where the plastic meets the metal would help. It is all easy to do (especially with
the wheel off) and appreciated by my wife too.

As for the front arches I found some images that show the end of the sill beam is blanked off about 35cm in from the hole that I poked the wire in so I tried a
longer bit and it did hit a dead end.

I'm well past all of this on my end. I found the same as you - that the beam that runs the length of the car is baffled. With enough wrangling, I did manage to get a wire run from the front of the car, through the baffle and out to the rear quarter area. But it was such a pain, I realized there was no way I'd be getting any sound deadener down that. So what I did after sealing up the big hole at the rear, is stuff thinsulate down the different sections of the beam as far as I could.

I also laid thinsulate over the wheel arches inside the quarter panel voids, put CLD/CCF/MLV and thinsulate over the inner portions of the wheel arches (where the rear fabric covers for the trunk attach, and laid a sheet of MLV over the trunk tools, cut to the shape of the trunk tray. At highway speeds, I now get very very little sound from the rear of the car.

What is very prevalent now though, is the amount of roar I get from the front. I stuffed the front pillars on either side of the dash with thinsulate, and lined them with MLV as best I could, but that doesn't seem to have been enough. I think the only fix will be to pull the dash completely and do MLV all the way up the firewall... which totally kills me. So much work, and so much risk of messing things up.

I've also CLD/CCF/MLV'd my floor and doors (with thinsulate in the doors too), CLD'd and thinsulated the roof... pretty much went nuts. I even bought some hydrophobic melamine foam from sounddeadenershowdown and tried stuffing that in the void in the front fenders behind the fender liners. That didn't make a noticeable difference.

MLV on the firewall... sigh.

Good luck with your efforts!

Johan, See post # 39 here http://*************/forum/f16/poten...43/index4.html and read in conjunction with the text below. For the ***** substitute ************* to complete the link. It looks naff but certainly works for engine noise and must help for the amount of roar you get from the front.

In hindsight it would have simplified install if the bracing bars had been removed prior to putting the sisalation layers in place.

The layers have slits leading to holes that match various hoses or pipes. The slits of one layer are vertically down, another vertically up, one horizontal and another more or less diagonal. Thus the slits are overlayed by adjacent layers.
The shielding rests below on the transmission housing and 10cm back into the tunnel and blanks off the tunnel. It comes up behind (but not touching) the engine and curves over to rest on the black bracing bars. While driving, It may rise there to contact the bonnet but there are no flapping noises. There is plenty of room for heat to rise and no contact with exhaust below.
The shield curves around horizontally as far as possible and slightly covering the suspension damper turrets.
I tried burning sisalation. The paper backing burns but quickly extinguishes.

I have just tried revving up to the redline in second gear on smooth bitumen. At that low road speed wind and tyre noise is more or less out of the equation i.e. leaving mainly engine & transmission noise.
I am blown away by how effective this sound-shield is. Engine noise at 7000rpm is now very similar to what I hear in everyday driving around 1200rpm in top.
I love it. No longer is it a somewhat tinny car but altogether more refined and there's no loss of fun factor.

Use this http://bit.ly/1Sf5Qp5

Thanks Porcupint. How did you come up with that link? I have had this problem with part of links seemingly rejected by this forum and someone else has had to come to the rescue. I will make a note of what I should be doing for later reference.

Just a link shortener https://bitly.com

@notout86, I saw those pictures before when reading on the other site.

I'm not a big fan of the solution if only for the aesthetic side of things. Additionally, I do intend to turbo my car soon, so heat is definitely a concern for me on anything I do. Also, I've never seen a product like that here in the states, so couldn't use it if I wanted to. I have considered pulling the cowl off and trying to put some MLV inside there. There are so many options, just depends on how committed you are.

Haven't read the whole post but having looked at the pictures I'm stunned by the fact that you have a sniff of body colour on the interior. On my last Z4, and the previous one that was missing from the exterior.

"the product" is merely foil insulation as used on houses and lining the inside of a roof e.g. in a shed. It is re-inforced by a laminate of fabric or plastic between the foil layers and often colored blue on one side so it is not so glary for installers. Sisalation is a trade name for one variety. On the aesthetics side I cringe myself but my wife and I agree it has reduced engine noise quite noticeably. We have just completed a 700km trip over all sorts of roads at mainly 100kmph and along with the silicone rubber seal for the holes at the rear we are quite happy.
The main remaining noise now is a low frequency thrumming ie not a rumble.

Appreciate the pictures. Thank you.

Excellent Thread!
 

GREAT JOB! :clap:

1. Based on your experience, how much of each of the sound deadening materials is needed for the FR-S/BRZ?
2. About how many hours did it take to complete this job?
3. Which supplier(s) is/are recommended for these materials?
4. If you had it to do over again, would you? If no, which sports car might you buy instead that's significantly quieter?

Thanks!

I ended up using approximately 80 sq ft of MLV (minus scraps, so probably 70 lbs into the car), 45 CLD tiles (could have used more), 25 sq ft of 3M Thinsulate Acoustic, and 4 sheets of closed cell foam.

I don't know, probably a good 30-40 hours working it alone over the course of a month or two. It wasn't a 1-day job. I had a handful of times I just did the entire afternoon working on it. Although I did drive the car during the process, so it'd be faster if you dedicated a weekend to it, because a fair amount of my time was assembly and reassembly (I'd take off a panel, work on it, then put it back together). In terms of budgeting your time, the biggest piece is the floor. I did it over a couple days so I had the seats in and out multiple times, if you could dedicate a solid day to it, I think you could bang it out, and then just do the doors separately at your convenience. Having a helper would speed things up immensely - a lot of my time was going back and forth betweeen tools, going back to measure things. if you had one person just cutting material and a person just installing it it'd go much faster. I also got the JDM interior pieces AFTER doing the sound deadening, so I had to have a lot of that taken apart a second time.

I got it all from Sound Deadener Showdown.

It's tough to say. I don't think I would be happy with the stock car 3 years later. I like everything about the new Impreza except for the vague 5-speed gearbox and anemic 148bhp engine. If they had an Impreza hatch with a BRZ gearbox and a 200hp motor I'd have been all over it. The reason I didn't go for a WRX in 2013 was the high price, crappy gas mileage, and the fact it was based on a previous generation Impreza.

That being said, every couple of months I'll drive past someone, usually a teenage boy, who shouts "Cool car, man!" at me, which I don't think you get in an Impreza.

In terms of non-Subarus, I'm too tall for a Miata and I got sick of FWD after a torque-steery, wheel-hoppy '97 Maxima, although to be honest I think I'd be pretty happy with a modern FWD sporty car with a manual gearbox. But the BRZ is cooler.

Just wanted to say that SDS sells a complete kit now for these cars, looks like their numbers are about what the OP used.