Is Your Exhaust a Little Too Loud? Try This...

[exe36m3]

BEFORE YOU READ THIS
This is for reducing exhaust noise (drone, growl, etc) for the interior cabin as you drive. This is NOT for the outside noise - you know, where people, neighbors, etc. all grimace when you drive by.

This mod WILL reduce exhaust noise inside of your car, so if you dropped like $10k on your exhaust, don't get all mad at me because you can't hear it anymore. (EDIT - if you went no cat/DP, no-baffle/short muffler, skip this. It's no help. This write-up is for stock or stock-ish layout systems.)

AN OLD GUY WROTE THIS
Also let me preface that I am OLD, like in my 50s old.
But I like loud exhaust too - ran Borla exhausts on my BMWs that set off car alarms.
However an exhaust generally should only be loud when you want it to be - usually on throttle and not when cruising on the freeway.

STORY, ALWAYS A STORY
I'm running the stock muffler, which sounds pretty good for a stock system. So I wasn't interested in changing it.
BUT, on the highway, it just drones. I get migranes so my sensitivity to low-sound probably adds to me noticing the issue.

A few months back I was looking at doing the subwoofer mod that's been well documented here and everywhere else online. It works great but I noticed guys also doing the trunk floor with sound material like Dynamat.

ORDERING & INSTALLATION
I jump onto Amazon and got their material (which is only rated as average). About $30 for 8 feet which is more than enough for our trunks. Install is super easy, use scissors (BIG ONES) to cut out and a ruler to help with size/measuring. Material has an adhesive backing, so cut, peel and apply.

OBSERVATION & IDEAS
Most of the stereo guys appeared to do the flat portion of the trunk - and do a WAY better job than I did. However, once I did the horizontal portion of the trunk, I had a thought. The battery area...

The muffler/exhaust exit sits toward the back of the car, just behind the bumper, under the rear of the trunk and right next to the battery. It's the source.

I decided to line the battery portion of the trunk too.
And did a sloppy job... with just average sound material...

RESULTS
My folks live an hour away, down a highway.

The previous week before the install, a visit to them had me with some pretty noticeable fatigue from the drive.
Post install, I was like, wait a minute, no headache. The drone was reduced enough that even my body felt better.

So again, old guy, cheap material, sloppy install.
But it worked for me.

PHOTOS

Above - hard to see but I ran a pretty big and solid patch of material on the battery wall closest to the battery. Sure I said it was all sloppy, but for this part, I got as much material as I could get in there.

Middle - this photo makes my OCD go crazy because its like a little kid just put stickers everywhere. But the right-side of the photo is the back of the trunk and the muffler sits there. I made that part of the battery wall as perfect as I could - less "grey" of the trunk - as much material as I could fit.

Bottom - yes the overall, it's a mess. But where I did pay attention to was the back of the trunk. Get as much material there as the muffler sits right underneath it (and almost parallel to the battery area).

CONCLUSION
Hope this was help to you all.

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[SupraSmashedBro]

I like it. Drone affects everyone differently, it’s good you were able to find a solution. I’m in a similar boat where I’d much rather the car be quieter than wake up the neighbors every time I start up my car

 

[exe36m3]

I like it. Drone affects everyone differently, it’s good you were able to find a solution. I’m in a similar boat where I’d much rather the car be quieter than wake up the neighbors every time I start up my car

Ha ha ha, agreed. The GTS roar - when you start the car and it well roars. It's fun right, but the neighbors have got to hate us! It's a leftover BMW thing - I heard a Z4 recently that does that too.

 

[i3igpete]

interesting, this guy did the same thing a few months ago and reported it did NOT help with drone.

 

[Timmy_Jones]

I just installed a full roll of this on my neighbors front door. He doesn’t mind the AWE cold start anymore

 

[exe36m3]

interesting, this guy did the same thing a few months ago and reported it did NOT help with drone.

Just watched it. Great video, helluva lot nicer install than mine!

As far as noise, I agree, it didn't work as well for him.

I'm ALL stock, but this guy is running no-cat/downpiped, single-titanium exhaust, short/small muffler with no internal baffling, etc. Also, the exhaust layout is essentially straight back, so can't use the design of the car underbody as well to dampen noise. (Thanks for pointing out that video, I updated this post).

But that's my guess. Sound engineers feel free to hit me over the head if I am incorrect.

 

[exe36m3]

I just installed a full roll of this on my neighbors front door. He doesn’t mind the AWE cold start anymore

What a great neightbor you are!

 

[Timmy_Jones]

What a great neightbor you are!

So curious what you’d think of the AWE exhaust. With such a sensitivity to drone, do you want the car louder than stock? Man if you’re in NH shoot me a DM and we can go for a cruise. I wonder if AWE is quieter inside than stock?? It’s way god damn louder outside

 

[exe36m3]

So curious what you’d think of the AWE exhaust. With such a sensitivity to drone, do you want the car louder than stock? Man if you’re in NH shoot me a DM and we can go for a cruise. I wonder if AWE is quieter inside than stock?? It’s way god damn louder outside

The AWE is like an art pirce to me! Amazing system. And next time I'm near NH, happy to buy a round and go for a ride!

But as far as loudness, I'll agree with you. The AWE uses pretty small mufflers, guessing it won't have any internal baffling, so it would essentially be a straight pipe/path still.

Exhaust tech is pretty interesting. I spent a bit of time with a Borla dealer in the 90s who also developed Bonzai motorsports (Norcal brand). There's the exhaust pulse - it's not a straight stream of gasses; flow at different RPM, baffling inside of the muffler itself, etc.

Generally, most aftermarket systems just go with essentially a perforated pipe inside a stainless cannister or box and maybe packed with steel wool. It produces more flow at higher RPM without restriction but at the cost of noise - which car people tend to like anyway.

Stock mufflers will have baffled/chambers and a bigger body for that compromise of flow and power and noise (you know, for the old people like me).

 

[Timmy_Jones]

The AWE is like an art pirce to me! Amazing system. And next time I'm near NH, happy to buy a round and go for a ride!

But as far as loudness, I'll agree with you. The AWE uses pretty small mufflers, guessing it won't have any internal baffling, so it would essentially be a straight pipe/path still.

Exhaust tech is pretty interesting. I spent a bit of time with a Borla dealer in the 90s who also developed Bonzai motorsports (Norcal brand). There's the exhaust pulse - it's not a straight stream of gasses; flow at different RPM, baffling inside of the muffler itself, etc.

Generally, most aftermarket systems just go with essentially a perforated pipe inside a stainless cannister or box and maybe packed with steel wool. It produces more flow at higher RPM without restriction but at the cost of noise - which car people tend to like anyway.

Stock mufflers will have baffled/chambers and a bigger body for that compromise of flow and power and noise (you know, for the old people like me).

My man. AWE is totally straight through, but what appears to be a bug muffler body is a Helmholtz resonator. Literally right when the car should be droning the bolts loose in the car…it doesn’t. Meanwhile it’s wicked loud. Give me a shout if you’re around. It’s amazing tech. I ran the exact same setup on my Focus RS and a friend on his GR86. If you like loud, it’s the best setup!

I think HKS is more of the standard tech and produced a much more civil note to it. I had both. Loved both. Gun to head I’ll always pick AWE.

 

[Loco38SUP]

I did the exact same thing but using Dynamat, it did help some but not as much as the sheet of MLV. I stitched 2 sheets together the same size as the battery cover and it removed 80% of road and exhaust noise.

My exhaust was so quiet that I had to turn the ASD back on. ?

Mass Loaded Vinyl

-RJM

 

[Timmy_Jones]

I did the exact same thing but using Dynamat, it did help some but not as much as the sheet of MLV. I stitched 2 sheets together the same size as the battery cover and it removed 80% of road and exhaust noise.

My exhaust was so quiet that I had to turn the ASD back on. ?

Mass Loaded Vinyl

-RJM

Any installed pics?

 

[exe36m3]

My man. AWE is totally straight through, but what appears to be a bug muffler body is a Helmholtz resonator. Literally right when the car should be droning the bolts loose in the car…it doesn’t. Meanwhile it’s wicked loud. Give me a shout if you’re around. It’s amazing tech. I ran the exact same setup on my Focus RS and a friend on his GR86. If you like loud, it’s the best setup!

I think HKS is more of the standard tech and produced a much more civil note to it. I had both. Loved both. Gun to head I’ll always pick AWE.

Thanks for the heads up! Pretty amazing when companies take the time to actually use a bit of science. I snapped a screenshot of the muffler design....

 

[Loco38SUP]

Any installed pics?

Here you go.

-RJM

 

[Timmy_Jones]

Here you go.

-RJM

Appreciate it!

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