Quieting down 3" exhaust. Suggestions?
 

I built a 3" exhaust with no Cat or Resonators flowing through a Full Boar Max 5x8x18 Stainless steel straight through muffler, and it is a bit too loud for my liking. I would like to quiet it down some without replacing the muffler in the rear. I am thinking of adding another small round muffler further up in the exhaust stream in the drive shaft tunnel. Does anyone have any experience with any low profile mufflers that would fit up there that work well for noise reduction?

lol at your tiny muffler.

Pretty much any glass pack will fit there. Or something like a dynomax bullet. My car is getting two bullets (both lengths in 3" diameter) in the tunnel because they're kind of light and the dollar to packing volume is really good for their weight. Supposedly they're alctually pretty decent at quieting cars down even though dynomax advertises some of the sizes as providing a maximum of 4 db (because red neck drag racers like their v8's loud and some of the rules state that there must be a muffler present but with no sound limit).

lol at you feebles and your feeble attempts.

running silly little glasspacks and bullet mufflers is like pulling the shades on your windows down to muffle the sound of your drumset. Instead, what you really need to to is line the walls with real sound absorbing wall panels.

https://www.miataturbo.net/attachmen...ine=1365083136

You need one of those and a single hotdog.

Dann

I've tried glasspacks in the past to quiet an exhaust down and they never seemed to tone anything down in my experience, just reduce rasp. I hate to buy something weld it in and find out it made no difference.

Option A





Option B

Then put in a bigger muffler. More packing volume in the exhaust = more quieter.

it's like you've never tried searching for a quiet muffler on this site.

it's like we haven't all agreed on a solution that involves the same muffler and resonator solution.

when you go outside on a -30°F, do you like to wear a light jacket or cover youself in as much extra material as possible? keeping in mind the circumference of your body doesn't change in this situation, only the amount of added material around you...

I know whats tried and true on the site, however that will require a complete redesign of my whole exhaust. I'm probably going to weld one of these in the tunnel upstream Magnaflow 12619 Muffler 3" Inlet 3" Outlet Stainless Steel Natural Each | eBay
which should lessen the noise quite a bit. I came here asking for an opinion on what small round mufflers do a good job on sound absorption that will fit in the tunnel. I realize I should have went with the enormous magnaflow from the get go but its too late now.

it's never too late. but you can keep wasting money trying to never satisfy yourself.

So you know for sure what works, but have decided not to do that anyway.

Some of us like to be difficult and not conform to the masses. honestly though, I didn't go with the large magnaflow because in my opinion it was too quiet for my taste. I wanted some noise so I went with the next size down muffler and it backfired on me being a little too loud for my taste. You live and learn.

Thank you for confirming my wise choice of not going with a Full Boar muffler lol

This could also be a contributing factor in my scenario, I gave it a shot and it failed. The first couple of hours after I put the new exhaust on it was perfect, then the muffler broke in its become a bit much for me. If I used a genuine magnaflow it probably would have worked out better. You win some and lose some. I don't feel it was a total loss as it does absorb a good amount of sound, and costs less than half of its magnaflow counterpart.

Well yeah, I'm just happy I wasn't the one to "find out the hard way" like you did. I'm glad you did it though cause now we'll have a documented case of it sucking. When I was doing research I couldn't find anyone that ran it on a miata.

But anyways, I'd suggest what the others suggested: replace it with a big 'ol maggie and don't look back. It will stay quiet and consistent, vs you adding even more weight to your exhaust, spending even more money, and in a while I bet that max boar will burn out even more and will sound even worse, and you'll probably have to replace it anyway.

who's car did you ride in to determine this?

unfortunately, I haven't have an opportunity to hear any for myself. Just though videos posted which sucks to fully judge, I know.

There is no such thing as too quiet in our cars. Our cars are LOUD as is.


Maybe I'm just getting old...QQ

I told my wife I'd like a corvette yesterday and she said it's because im getting old.

I made a thread on another forum about my vette. I named it "midlife crisis-mobile".

I'm not in denial bro.

where as brain is like Cleopatra, the queen of de-Nile.

Why am I in denial?

My plan is to run the big fucking muffler, and if I want more loudness I'll do this with an old TB or something:

Let's see this vette, is there a thread on here about your other daily?

ORRR,

Just add a connection there and unbolt as needed :party:
Its nothing special. 04 Base auto with 2.73 rear.

*edit: moved pics so its not as bad of a thread jack:
https://www.miataturbo.net/build-thr...39/#post884831

/threadjack

at least the corvette i pointed out was a zr1.

Rule of thumb: You'll spend much less money and will be much happier with you're modded car in the long run if you just spend the money to do it right the first time. That's one of the great things about this forum -- learning from others.

And before accusing me of being a "holier than thou" type, consider that I routinely ignore my own advice because I'm so darn cheap (and, yes, end up spending more to fix stuff I cheaped out on).

One of my upcoming fixes (after I swap my diff) is a decent exhaust. It WILL have a Magnaflow.

I did a G8 instead of a Corvette. Had too many 2 seat cars. Plus, it was cheaper.

Next time turn up the volume.

*

I find my straight through 3" with the Magna 5x11x22 to still be too loud inside the car. From the outside at the dyno it sounds really good.

https://www.miataturbo.net/members/v...nstalled-1255/

do you have a cat?

Mine passes the wife test, but it's still no stock muffler.

I had planned on getting a plastic bag, filling it full of expanding foam, and placing it under the parcel shelf to see if that helped deaden the sound. I too feel that the car is too loud at certain RPMs. I think it is just the resonant frequency that I dislike, because if I increase the rpm a bit it is very quiet at cruise.

I want a new stingray

I have a cat and a resonator. I have no drone or resonance whatsoever. It could stand to be a little quieter of an exhaust, but it's better than most.

I do as well, but at 2700-3000rpm it's a little loud.

OP, have you checked to ensure your exhaust isn't vibrating against anything under the car. Mine was touching the 5 point harness eye bolt under the car. It made it sound like the exhaust, but once I shortened the bolt the noise was significantly reduced

Brain,
What cat and resonator are you using? I hope to build my exhaust soon and know that I want to follow the well beaten path.....

Yeah, I have a Magnaflow high flow metallic CAT. It still drones a bit too much at around 3000rpm. My noise tolerance is lowering as I age.

+1000

I run a 3" decat with 2 resonators and a straight through muffler which is marginally loud for daily driving. I added a baffle to the muffler which quietens things considerably but for some reason I am not happy with that either.

Sometimes being loud and obnoxious is part of the fun.
(Next project will be a variable exhaust.)

I agreed 100% with the above when I had just finished the car and I loved my straight pipe. I want to quite it down now :facepalm:. I like what Brain has done with the exhaust and will probably go that route in the future.