Anyone Using Two Mufflers In Series (inline) to Reduce Noise/Drone?

[Dibbons]

I'm mainly asking about two standard mufflers, not just muffler and resonator. However, any comments on the subject will be appreciated. Thank you.

 

[65PlymSatellite]

Super interested in this as well…

 

[496 polara]

The key is having enough room. I have done it twice,both on pickup trucks.

My 86 Dodge Ram had a mild 360 with headers into a 3" single exhaust. Had a straight through (think Magnaflow) type muffler in the stock location and a Dynomax Super turbo in the tail pipe under the bed. Had some growl at WOT but was pretty tame other wise.

My current 82 Chevy C10 shortbed has a 454 with headers and a 2.5 dual exhaust. Magnaflow before the axle and Dynomax Super Turbo under the bed where the spare used to be. More engine noise than exhaust note.

Space limitations on a car make it hard to do with standard size mufflers. I still think longer glasspacks in front of the mufflers works well.

If I can figure out a way to get four mufflers under the 72 Newport I am all for it. If the 493 finds it's way in there anyway.

 

[s/w theo]

I think Jimmy Adison used that kind of set-up way back when on the "Silver Bullet" 67 GTX as a way to quiet the car down. I'm pretty sure it worked well too. Check into what was done to make it all fit.

 

[HawkRod]

Tell me about limited room!

I want my daily driver 69 Corvette to be quiet, so I added some 12" resonators. There was one spot where they fit in pretty nicely. Below is a picture with them in place after but before final welding of the system.

I can't tell you how they sound because the car isn't running yet. Plus, even after it is: it went from a poorly running stock 300 HP 350, small cast iron rams head exhaust manifolds and 2" exhaust to a 383 stroker, headers and 2.5" exhaust. I bought a Pypes system with the quietest mufflers (Turbo Pro), but I wanted to make sure it wasn't loud, so I added the resonators as shown. They came from Summit and are only 12" long.

 

[toolmanmike]

I'm mainly asking about two standard mufflers, not just muffler and resonator. However, any comments on the subject will be appreciated. Thank you.

I wouldn't want the double restriction. There are dozens of threads here about exhaust drone and what you can do to stop it.

 

[Don Frelier]

I think Jimmy Adison used that kind of set-up way back when on the "Silver Bullet" 67 GTX as a way to quiet the car down. I'm pretty sure it worked well too. Check into what was done to make it all fit.

Those were in parallel not series and the intent was to reduce backpressure.

 

[Don Frelier]

Hemi mufflers work well.
I took the 3 chambered Magna flows off my Charger and installed the hemi mufflers.
Much,much better at 2,000 rpm up a grade.

 

[not so famous bob]

Hemi mufflers work well.
I took the 3 chambered Magna flows off my Charger and installed the hemi mufflers.
Much,much better at 2,000 rpm up a grade.

dual 3 1/2'' bullet mufflers , with 3 1/2'' spiral cores welded about halfway up inside them . Dumped in front of the rear end , no drone , no back racking , but fairly loud , with almost no restriction ...

 

[66fs]

You can add good glass pack mufflers like the 65 HP 273 exhaust, in series along any straight length after the axle. Virtually no restriction and makes a noticeable difference in normal cruising noise.

 

[redchihuahua2004]

An alternative to two "mufflers" would be use of a Helmholtz resonator to cancel out the unwanted resonant frequencies (aka drone).

 

[AR67GTX]

I’ll second the Hemi mufflers from Accurate. At idle in my 66 they have some of that rocks in a tin can ruckus, but off idle they are pretty quiet and I haven’t noticed any drone - very quiet. Full throttle they will roar. On my 67 GTX I have Dyno Max mufflers on my TTI system and while not loud they do have some drone at cruise speed.

 

[69hemibeep]

I put these as the only muffler on my AMX and it sounds like a factory car no drone just a little rumble

Thrush Muffler Mellow Performance Tone​

 

[33 IMP]

Those were in parallel not series and the intent was to reduce backpressure.

Agree. I thought years ago that they were in series too, found out since that that was not true. Four Cadillac mufflers in parallel.