Quieter muffler?

[MikeC5]

I currently have an original (repro) muffler on the car and it is a bit loud.  It scares my dog who won't get in the car because of the noise.  Has anyone tried a similar sized muffler that does more muffling?  If so, what brand/part number did you use?

[Minibago]

Hi Mike,

Most mufflers of the correct pipe diameter should work, a longer box will make things quieter, two in line is also a design used by luxury car makers to quieten the sound. Jaguar for the XJ6 used one at the bottom of the engine pipe split into twin pipes, another under the rear passenger cabin on either side and one more under the boot on either side. Under hard acceleration the intake roar from the triple SU’s were all you could hear.

Do you have a leak at the manifold or engine pipe to manifold or a hole in the muffler body causing the excess noise? (A backfire can create a hole)

Another option is that the muffler internals have corroded away providing a straight through sound.

The last option is to look at getting another dog. 🤔

[RichBad]

I’ve got a 6” diameter 25”long muffler on mine - it’s a straight through and is pretty quiet.  Length of the muffler makes a big difference.  I also went 2” all the way through on mine (rather than reducing after the muffler).

[MikeC5]

Thanks guys.  I'm sure it's quite a bit shorter than 25" and I know you can see through it from end to end.  I'm pretty sure everything is buttoned up tight but will check when I wake it up after hibernation soon.  I haven't put many miles on it since getting it on the road a few years ago so I don't think corrosion is an issue (and it seemed loud when I first started and and began driving it).  I figured that's just how they were 'in the day'.  I used to have an MGB and had tried running a straight thru glass pack-type of muffler and found it to be too loud for every day driving. 

[Mattml430]

Rich got mine for me which is the same as his. It sounds great on the 6cyl also. 

[Pete K.]

Hi Mike, I've got a VERY old 17" X 6" straight through on my '25. All is surface rust but it seems to do the job OK when engine is running. I plan to replace it with a similar one Rich and Mattml430 speak of.

[MikeC5]

Thanks guys.  I gotta get under there and see what I have.  

[Mattml430]

Here’s a pic of mine. I can get a better picture if you want. 

[John McEwan]

On 4/4/2021 at 9:03 AM, RichBad said:

I’ve got a 6” diameter 25”long muffler on mine - it’s a straight through and is pretty quiet.  Length of the muffler makes a big difference.  I also went 2” all the way through on mine (rather than reducing after the muffler).

What’s a muffler the same as that cost? I’m thinking the 2” all the way would be better for performance as well.

[Alan Cutler]

10 hours ago, Mattml430 said:

Here’s a pic of mine. I can get a better picture if you want. 

 

Hey Matt, gotta ask, what's the breed?

 

[RichBad]

11 hours ago, John McEwan said:

What’s a muffler the same as that cost? I’m thinking the 2” all the way would be better for performance as well.

The one on mine and Matt’s is the same.  $195AU (stainless, 2” in/out, 24” long, 6” diameter straight through.   Got it through Rowville Exhausts in Bayswater (end Stud road) I think the manufacturer was Growl.

[Mattml430]

10 hours ago, Surf City '38 said:

 

Hey Matt, gotta ask, what's the breed?

 

That’s Dukey he’s a German Shepard. Gotta be on ya, near ya, or leaning on ya. He’s a beautiful boy but lovingly painful sometimes. All 50kg of him. 

Edited April 9, 2021 by Mattml430 (see edit history)

[Sasha39]

Seems a bit odd that Dukey is such a loving beautiful boy, well I mean being manufactured by "Growl" you'd think he'd be a bit on the mean side?

Love your work!

Edited April 9, 2021 by Sasha39
Spelling (see edit history)

[JACK M]

9 hours ago, Mattml430 said:

Gotta be on ya, near ya, or leaning on ya. He’s a beautiful boy but lovingly painful sometimes.

 

My guy is the same way, Loves to ride in the pick up but difficult to leave in the back at the store as he barks and whines like he's being beat.

Separation anxiety would be politically correct. I call it bitching.

But we love each other.

 

 

 

[nearchoclatetown]

MikeC, there is information on mufflers on the DBC website. It gives the proper sizes of length, diameter, etc. in the Garage section. These stainless mufflers are the cat's meow, will last for ever. 

[MikeC5]

Thanks guys.  I did some googling and found that Walker has a muffler worksheet that can help narrow down a muffler based on desired dimensions, number of inlets/outlets, etc.  I've got a 6" diameter, 25" long muffler body coming with 2" inlet and outlet (ID) coming.  It's not stainless as I want to be sure I like it before committing much money (it's only $40).  I'll either have to cobble and adapter or have a new tail pipe made but that's not a big deal.

That's Diesel in the back seat.  He may look mean but he's a big chicken when it comes to loud noises

By the way, the muffler on there now measures around 5" diameter by 18" long.

Edited April 11, 2021 by MikeC5 (see edit history)