Quietest Free Flowing Muffler

Go online and have a look, then ask him about those under the 'universal' section. They don't just make for specific applications.

The fact is that there is an unserved market for a performance muffler that's not too loud for vehicles that don't run cats. That's probably the wild card. Removing the cats significantly noisies one up. There doesn't seem to be much in between factory oem and too loud - other than the dynomax super turbos. Which is probably what I'm going with next.
 
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5spd GT said:
I thought the race bullets were just flat-out loud :shrug: ...or am I thinking of something else...

89sleeper - What were the temps and humidity the days you dynoed? That is interesting...
Race bullets are a very loud muffler. It depends on what car they are on.

It was in the middle of summer in South Florida. I don't remember the exact temps and humidity but it usually around 90 for both. It was done on the same day.
 
I've had three types of mufflers on my car, each with an offroad H-pipe. I had 3 chamber flows with turndowns, a dynomax super turbo catback, and the american thunder catback. The 3 chambers were quietest and the 2's are the loudest... dynomax was quiet but still quite noticable
 
I use 3 chamber Flowmasters. The part that made the biggest difference for me was using an offroad X pipe instead of an H (BBK) I run long tubes and the Xpipe with the three chambers and my car sounds stock unless I lean on it.

I live in suburbia and work really late on the weekends so I need the quiet.

My 2 Cents.
 
jb89coupe said:
Sounds like it's time for a new girlfriend. :D


That's what I'm thinkin'. She should just learn to deal with it or not ride in the car. As for avoiding the attention of Johnny Law, MAC's sound good with out being too loud. That's what I run without issues with "The Man".
 
tjm73 said:
That's what I'm thinkin'. She should just learn to deal with it or not ride in the car. As for avoiding the attention of Johnny Law, MAC's sound good with out being too loud. That's what I run without issues with "The Man".
Ughhhhh, are you kidding? Mac's are as loud as 2-chamber Flows and they drone like crazy. Don't get me wrong, they sound good and very muscular, but quiet, they are not.
 
Gearbanger - I'm in the same boat as you. I've been experimenting with different bits and pieces for over 2 and half years and it's still too loud.

Originally an F-body single inlet, dual outlet Flowmaster. Followed that with a custom-ordered Bassani Quiet Thunder. It was fine a for about a month and then got extremely loud. Followed that with a SpinTech RV muffler with a single SpinTech resonator upstream. Liked the sound/volume but wanted to re-configure the backend for a center outlet exhaust tip (right in the middle of the car) so I ordered a reconfigured SpinTech muffler (actually a sprint car muffler) and a second resonator - that combo was way too loud. So I pulled off the 2 inline SpinTech resonators and replaced the with a Magnaflow 3" in/out - it's even louder than the resonators are.

That does it. No more $$ on the exhaust til I'm certain I can quiet it down. So I'm gonna try a stock C5 Corvette set up on mine (will fit on mine I think; not on a Stang). If that doesn't work, then the biggest, quietest dynomax super turbos I can find.
 
Michael Yount said:
Gearbanger - I'm in the same boat as you. I've been experimenting with different bits and pieces for over 2 and half years and it's still too loud.

Originally an F-body single inlet, dual outlet Flowmaster. Followed that with a custom-ordered Bassani Quiet Thunder. It was fine a for about a month and then got extremely loud. Followed that with a SpinTech RV muffler with a single SpinTech resonator upstream. Liked the sound/volume but wanted to re-configure the backend for a center outlet exhaust tip (right in the middle of the car) so I ordered a reconfigured SpinTech muffler (actually a sprint car muffler) and a second resonator - that combo was way too loud. So I pulled off the 2 inline SpinTech resonators and replaced the with a Magnaflow 3" in/out - it's even louder than the resonators are.

That does it. No more $$ on the exhaust til I'm certain I can quiet it down. So I'm gonna try a stock C5 Corvette set up on mine (will fit on mine I think; not on a Stang). If that doesn't work, then the biggest, quietest dynomax super turbos I can find.
Mike, I'm looking pretty closely at a pair of the Magnaflow XL 3-chamber 4x9 ovals (model number13256) set up right now. From the few sources that have pointed me toward them, they seem to be the quietest sounding, with the most flow potential. Whatever I choose has to move enough air to support 9psi and around 425fwhp. And at the same time, has to fit the constraints of the little muffler space given with my '96 Cougar. These particular mufflers have a 24" over all body, with an 18" canister, so it might be tight for my needs. According to Magnaflow though, the longer the muffler, the quieter the tone. I’ll be combining them with a custom mandrel bent system consisting of a custom X-pipe and 2 high-flow cats (probably Magnaflow as well).
 
How is that muffler configured on the inside? Mine is the 18" casing/24" overall. It is straight through with a perforated full size tube inside, packed with sound deadening material on the other side of the perforations. Adding it did virtually nothing to quiet down the SpinTech.
 
These are a chambered design, not strait through.
xlchamber.jpg

Direct quote from the Magnaflow site...
"MagnaFlow XL 3 Chamber Mufflers use a unique combination of large diameter perforated tubing and strategically placed sound baffles to reduce unwanted resonance and help your engine create horsepower.

The sound baffles tune the sound waves using calibrated tuning gate openings that allow portions of the waves to pass through. These tuned waves reflect off the back wall of the muffler and cancel out unwanted harsher sounds.

The large diameter perforated core eliminates the flow restrictions of a louvered style core. A careful balance between perforation size/spacing and the baffle tuning gate make for a great 3 chamber performance muffler."