Mufflers?

What is the best combo of low noise/mellow sound and still a good measure of performance on the market currently?

Ive been running 3 inch magnaflows older Al. case and the newer SS case for years and I need a bit more stealth sounding muffler.

Thanks.

l'm interested too. My full 3" system with x-pipe, Summit turbo mufflers (and glasspacks for resonators) is also too loud.
Maybe I'm just too old

Bassani or Hooker Aerochamber. I have Bassani's now on one car and have had the Aerochambers in the past. Neither is obnoxious and sound mellow.

The Bassani's I have right now are quite at idle and get louder as you get on it but, still not ridiculous.

Anther idea, go on You tube and find clips of different mufflers, they have plenty on there to listen to.

The old Thrush Turbos can't be beat, especially at 28 dollars each on Amazon.

I had them and they were surprisingly quiet, upped my performance a bit, and had a great sound at idle (318 2bbl W150)

Don't put them on anything making any real power. They choked at a bare minimum 50 HP out of my 440, and honestly I'd say it was closer to 75-100, I'm talking HUGE difference on a 550 HP engine. There was an episode of MotorTrend's Engine Masters (after I figured out that these were my problem) where they killed something like 20-30 HP on a 350 HP engine. But man they did SOUND great.

OP - run the longest case you can fit, 20 inches is great. I replaced my 3 inch in/out Hush Thrush Turbos (14 inch case) with 20 inch case 3 inch Ultra Flos and was surprised it is actually quieter with the Ultra Flos which are straight through. The long case makes a huge difference. It also made 479 WHP through the Ultra Flos with a stock stroke 440, so I don't think they are holding it back much power wise.

By your logic ANY 440 would gain 100 horsepower if you cut the pipes off at the manifolds and ran straight pipes.

Gotcha.

Yes, that is exactly what I said.

Sorry if the post hurt your feelings, it was not intended to be an attack on you. I always liked the sound and thats why I gave them a try. But it seems like your reading comprehension skills are about on par with your comprehension of exhaust scavenging if you think that is what my post implied.

IF YOU CAN HEAR WHAT IM TYPING YOUR PIPES AINT LOUD ENOUGH!!!!

Check out Pypes Race Pro and Street Pro mufflers. Mellow at low rpms and loud at wot.

I run a pair of mufflers from Accurate Ltd. They mimic the OE performance muffler. The run just fine on my bigblock GTS. Not sure how they would run on a big inch motor putting out a lot of power.

I've been 10.0's at 133 mph with Dynomax Ultraflows.

They are very quiet and easy to live with driving around and give great performance on the throttle.

I seem to recall a conversation on here years ago about the capability of the Dynomax Ultraflows.

Video of comparison Flowmaster vs Dynomax at 700hp: https://www.youtube.com/watch?v=vPue52BBAaU

Various Dynomax offerings: https://www.youtube.com/watch?v=ORGyLVmFqmY

Yep - they are quiet & sound "flat." The reason they are quiet, is they have small flow tubes internally. The Thrush California Boss Turbos with 2.5" inlets & outlets, have 2" diameter flow tubes inside. I used to look at blueprints of them all the time! They are NOT performance mufflers.

Flowmasters were consistently the WORST flowing "performance" mufflers we tested - always. (2 chamber, 3 chamber, & Deltas). The internal steel plates were walls, & did not promote high flow - they did just the opposite.

I like Dynomax Superturbo (I have long on my truck, and short on my Challenger)

Here's a chart with flow comparisons.

I'm very happy with my Dynomax Ultra-Flo in a 20" body length. I would definitely buy them again.

Dynomax stainless steel Ultraflows for RV duty are worth looking at.

I have had the 2.5” pipe size 34” long for 22 years now with a 16” long as an exhaust “tip.”

This created a slightly louder than stock “low rumble” system.

If I had to do it over I would add another 16 inch long SS Ultraflow right behind the catalytic converter and a 90 degree T stub near the rear bumper. I would start with T stub 48 inches long and keep shortening it until I got the best noise reduction at 1750 rpm.

I went from flowmasters to Ultra Flows on my Barracuda. While they are not quiet they are WAY quieter than the flowmasters, the car also picked up .1 at the track as well. It makes about 550-600HP and for what it is the volume level is acceptable.

https://youtu.be/FEvTC9HFE0I

Like others have said you might try throwing a glass pack in the system if you can fit one. My Jeep has a flowmaster 40 series and as I got older I gor tired of the 4.6L I6 making to much noise. I couldn't decide on a muffler change so I just had a muffler shop stick a 36" glass pack in front of the muffler. It kept the same sound but knocked the volume way way down. Now I can hear the rear end whine

Where are you mounting them and where are your tailpipes coming out?
I had a three inch system on my last street and strip Duster with a set of the older (2004 or so) 14 long 7 inch wide with 3.0 inch side inlet and center outlet Magnaflow muffs, not the stainless Ultra flow like now.
Those muffs were mounted behind the rear end between the sub frames and the outer body 1/4 panels exiting at the rear bumper, sounded good inside and out at idle or part throttle and di get louder at WOT but not really bad inside. I could talk to people in the car and listen to the radio, roll up the windows and not notice a lot of exhaust noise, no drone or resonant frequency that I remember now at any cruise RPM up to 3500 RPM which was around 80 MPH
Where you mount the muffs and where the tail pipes exit can make a difference on what you hear inside when driving

While we're waiting for OP, here's where my tailpipes are (the turndowns are stuck right in the glasspacks). Mufflers are in the stock A-body locations.

Part of the problem is that there's no back seat and a sheet metal trunk-firewall with no sound insulation (so far).

What Cab says, plus:
The shape of the car can matter; had a wagon that I tried 3 sets of mufflers just looking for the right sound and livable loudness.
My muffler shop guy still laughs about that episode.
I've had 2 Dusters that came with Flowmaster 40s that sounded crisp & had a nice bass tone, not tinny; had to add tailpipes to one to quiet one car.
Neither had any drone to speak of, contrary to common experience.
Also there seems to be some difference in the engine's power: a strong 383 sounds different than an average one with the same muffler.
Size as well: my 368" drag car with Race Bullets is a bit quieter than the same system with 448".
I've done 3" with 2.5" tailpipes and it quieted the car; no apparent butt-dyno difference but no ETs to report.
I tend toward the Dynomax SuperTurbos, which also sound different on different cars.
The RR/GTX/etc tips seem to accentuate the exhaust pulses with a crisper tone.
I'm strongly tempted to try their UltraFlows on the current 383 RR; it has SuperTurbos and they're surprisingly quiet all the time.
Unfortunately that video doesn't really tell much about tone when driving.

To give a sample of driving around in my 383 RR with 2.5” pipe and Welded Ultraflo mufflers #17513 and no X-pipe or H-pipe. The recording was made with the windows down.
Basically stock, with a .474 life purple cam and Demon 750 carb.
Ron

I would lean toward Dynomax or Walker UltraFlos or Super Turbo Mufflers. I did have a pair of Summit Racing Mufflers on another car and they weren't too bad either.