My exhaust is too loud - how to make quieter?

[garry viohl]

I know, most people want louder. But I think the car is too loud around town.

482 cid FE
cam is 240/246 110 lobe sep
18 inch long glasspacks (with packing) with louvers pointed with air flow
3 inch pipes

I have installed dynatech vortex insert cones at inlet of muffler
they claim 2-3 decibel reduction

I bought 2 more and installed them in the tailpipe, cant hear much difference

I thought of installing heavy steel wool in front of cones, front and back

Any ideas? Thanks.

[menace1]

Your kidding right? Be loud and proud I say...Otherwise install a undercarriage exhaust system or one of those Tesla motors may do the trick.

[Jeff Frigo]

[SunDude]

Originally Posted by Jeff Frigo

+1

This is the correct answer IMO.

[tkb289]

Garry,

I do not have any direct personal experience or affiliation, but understand that Stainless Specialties makes custom mufflers with a ceramic acoustic liner that according to their web site has a 'subdued sound with great flow'.

Here is a link to their web site if you are interested ...

Stainless Steel exhaust components•


- Tim

[mdross1]

Originally Posted by tkb289

Garry,

I do not have any direct personal experience or affiliation, but understand that Stainless Specialties makes custom mufflers with a ceramic acoustic liner that according to their web site has a 'subdued sound with great flow'.

Here is a link to their web site if you are interested ...

Stainless Steel exhaust components•


- Tim

My choice was belly exhaust using custom mufflers from Stainless Specialties love the sound and the performance out of 460ci.

[mickmate]

Make them 2-1/2" x 24" with the louvres facing the motor.
Classic Chambered Exhaust Inc. - Products The 2524's

[patrickt]

Gary, I think the absolute truth of the matter is you're going to have to get new pipes made. I have the Stainless Specialties "quieter pipes" and they do pretty well. Short of new pipes, everything else is a just a gimmick.

[Jeff Frigo]

Originally Posted by patrickt

Gary, I think the absolute truth of the matter is you're going to have to get new pipes made. I have the Stainless Specialties "quieter pipes" and they do pretty well. Short of new pipes, everything else is a just a gimmick.

I have talked to guys in who race A Production cars (see below) in vintage races that swear that these work well with little to no loss in power.

Dynatech Accessories - Auger Style Muffler



A-Production

AC Cobra (427cid)
1970-72 Chevrolet Corvette 350cid
1965-67 Chevrolet Corvette 427cid
1968-72 Chevrolet Corvette 427/454cid
DeTomaso Pantera 351cid
Ford Boss 429 429cid
Shelby GT-500 428cid

[patrickt]

Originally Posted by Jeff Frigo

I have talked to guys in who race A Production cars (see below) in vintage races that swear that these work well with little to no loss in power.

Dynatech Accessories - Auger Style Muffler

I've heard that too. But there have also been threads on here where guys have tried them and said just the opposite. I also suspect that the psychological force of "believing they work," after you've gone to the trouble of buying and installing them, might also come in to play. I know I had been around more than one Cobra that just plain hurt my ears (from both outside the car, and inside) so I dealt with the issue when SS was fabbing the pipes. I really like their "quieter pipes" on my FE, but it's going to cost him a couple of bucks. On the other hand the auger inserts are only $15, so WTF, he might as well give it a shot I suppose.

[Dwight]

I replaced my 2 1/2" x 24" mufflers (louvers facing away from motor) with Classic 3" x 28" (louvers facing the motor). They are a lot quieter and still sound like a Cobra, deep rumble at idle.

Dwight

[Jeff Frigo]

Originally Posted by patrickt

I've heard that too. But there have also been threads on here where guys have tried them and said just the opposite. I also suspect that the psychological force of "believing they work," after you've gone to the trouble of buying and installing them, might also come in to play. I know I had been around more than one Cobra that just plain hurt my ears (from both outside the car, and inside) so I dealt with the issue when SS was fabbing the pipes. I really like their "quieter pipes" on my FE, but it's going to cost him a couple of bucks. On the other hand the auger inserts are only $15, so WTF, he might as well give it a shot I suppose.

Patrickt:

I have not been able to find anybody on the forum that has tried them. I have searched. Do you think you could find that thread. I was planning on trying them this winter, but if they are NG, I would like to save my money. $15.00 is no biggy, but the rest of the process for existing ceramic coated pipes are.

[ACademic]

Originally Posted by mickmate

Make them 2-1/2" x 24" with the louvres facing the motor.
Classic Chambered Exhaust Inc. - Products The 2524's

Mickmate, you have a lot of experience with the Classic Chambered. I'm running the 3" (louvers facing the motor) on a 22" case and they sound great at idle but sound "less Cobra-like" on moderate/hard acceleration. In your opinion does your suggestion above get the overall sound back to that classic Cobra gurgle throughout the rpm range? It's really hard finding well-prepared sound clips on some of these options.

[CHRIS DAMSCH]

Add twin turbo's. That should quiet it down.
Or put a cam in with a 114 lobe separation and lower your compression a little.

[bobcowan]

A while back I welded in a set of mufflers from Classic Chambered. They look good, and sound great. Definatly a reduction in noise levels. More importantly, the sound is a little deeper, without the harsh "blatt" of the stock FFR mufflers. Pretty inexpensive, too. Classic Chambered says they make more power, but I can't say one way or the other on that.

I wear earplugs for any trip more than 10-15 minutes. The exhaust note is fairly quiet. But wind and tire noise will wear you out; especially on a concrete roadway.

[mickmate]

I have tried the Stainless Specialties mufflers, Hedmans and keep coming back to the Classic Chambered. I have found even the 3" x 21" with louvres facing the tailpipes make it relatively easy to drive and still be able to hold a conversation with the passenger. As pointed out the wind and road noise starts to override exhaust noise at speed anyway. I like the tone of the Classics it's a deeper smoother sound with good throat but it sure makes that right pedal a volume control. This is Davids FE with the Classic 3" louvres facing back. See what I mean about wind noise!
Cobra in Maryland - YouTube

[Mdman352]

This is with the Cobra Pak.

mdman352's Channel - YouTube

this is with whatever came with the Contemporary pipes.

mdman352's Channel - YouTube

[Jeff Frigo]

Originally Posted by Mdman352

This is with the Cobra Pak.

mdman352's Channel - YouTube

this is with whatever came with the Contemporary pipes.

mdman352's Channel - YouTube

Sounds the same, maybe a touch quieter with the first one.

[garry viohl]

What about using these? They have a perforated core instead louvers.

MagnaFlow 18129 - MagnaFlow Glasspack Mufflers - Overview - SummitRacing.com

MagnaFlow glasspack mufflers feature a free-flowing, straight-through, perforated core and non-fiberglass acoustic packing material. They will deliver a smooth, deep tone to your rat rod, street/strip machine, or classic musclecar. They are proudly made in the USA from 100 percent aluminized steel with precision robotic CNC welding.

[vatdevil]

Have 3 inch mufflers in use. I regret it. Should of gone with 3.5