How to quiet down a stroked 383

[RichardGoesFast]

Had my stock 383 bored and stroked and put back in my 1970 Road Runner last month. Motor has stock manifolds and stock exhaust system. And, it's much louder. On dyno we got 420 hp and 530.5 lbft. Wife says it sounds like a Cigarette boat. Not sure on that, but it is much louder and does have a drone around 2000 - 3000 rpm.
Does anyone know how to quiet down this type of install? I've talked to an exhaust specialty shop that seems to know classic Mopar and they said they can fit a resonator on either side of gas tank. They also said they can't predict exactly how this will effect the sound. I just want to get the car a bit quieter, kinda like it was before the 383 was built. That was a bit loud, but sounded great and was no problem at all.
By the way the car has A LOT of power. . .

 

[F4R/T]

Resonators, smaller pipes but that may choke it up .. premium mufflers that don’t have drone issues.

 

[gdrill]

A better cassette deck, super triaxles with a high quality amp........and some ear plugs for the wife.

 

[diesel_lv]

I've got a 383/496 stroker w 2-1/8" stepped TTI headers, 3" exhaust w H-pipe. Crank hp/tq is 610/670. It is not loud at all.
New video by john wilson

 

[Pool Fixer]

I had a very similar problem in my 440 charger many years ago. When i put the car together I was running headers with 2.5” exhaust/h pipe/2 chamber flowmasters. Car always sounded awesome. When I Switched to HP manifolds with the same exhaust system it sounded exactly like what you are saying.

I installed summit brand cherry bombs on either side of the gas tank and it totally resolved the problem.

Attached is a video of the car running.

Exhaust

 

[Don Frelier]

An h-pipe will help.
Do you have tips on it?
They help as well

 

[hunt2elk]

I wouldn't mess around with resonators. Sounds like you just need some different mufflers. Dyno Max Super Turbos are decent. Mandrel bent TTI 2.5" with a H-pipe and Super Turbos will flow good and not be obnoxious if you want to upgrade the whole thing.

 

[PROSTOCKTOM]

If you're not running a crossover I would install one before I did anything else as it will help balance the exhaust pulses.

I would run the largest Turbo mufflers you can get away with if you want it to be quiet, but not dead.

Tom

 

[Will-Fonkjam]

What does that sound like?? "Wife says it sounds like a Cigarette boat."

 

[6PKRTSE]

I have 3" all the way back and added 3" dynomax cherry bomb style mufflers on either side of my gas tank before the tips and it made a huge difference. No more drone and much quieter at cruisin speeds. Didn't seem to take away from the nice thump at idle though.

 

[Pool Fixer]

run the cherry bomb/ resonators. It’s the cheapest and easiest solution and for most of us, the only DIY solution. I did mine with a saws all and a few muffler clamps. Turn the clamps “up” and only your hairdresser will know!

 

[RichardGoesFast]

Really interesting idea. I like it. I'm talking with Accurate Exhaust out in Oregon about resonators later today. Possibly stock ones, but this is a cool idea.

 

[RichardGoesFast]

I have 3" all the way back and add 3" dynomax cherry bomb style mufflers on wither side of my gas tank before the tips and it made a huge difference. No more drone and much quieter at cruisin speeds. Didn't seem to take away from the nice thump at idle though.

Like this idea!

 

[RichardGoesFast]

What does that sound like?? "Wife says it sounds like a Cigarette boat."

A Cigarette boat sound is like straight through pipes. Loud as all f@#^! (my car doesn't really sound like that, it's a little bit of an exaggeration for sure)

 

[RichardGoesFast]

If you're not running a crossover I would install one before I did anything else as it will help balance the exhaust pulses.

I would run the largest Turbo mufflers you can get away with if you want it to be quiet, but not dead.

Tom

Will definitely consider the crossovers. Thanks for the idea.

 

[6PKRTSE]

I have H pipes and X pipes on all my cars besides my street strip Challenger. It does nothing to quiet them down. Just gives them a different pitch.

 

[Kern Dog]

I think that x and h pipes do have some effect on reducing some noise. I suspect that exhaust pulses collide and do cancel each other out to some small degree. This is the principle behind Flowmaster mufflers. In short, they redirect the exhaust to smack back into itself.

 

[SlinktRR]

Dynomax super turbos are very quiet, maybe too quiet. My car has 600hp and at idle to 1500rpm the car is pretty mellow driving through the neighborhood. Screams at WOT. I also run an h pipe, I don't think that will have much of an effect on sound volume but if you don't have it and are already doing exhaust work I would add that or an X.

 

[sjmedine]

Maybe try some HEMI mufflers!

 

[RichardGoesFast]

Dynomax super turbos are very quiet, maybe too quiet. My car has 600hp and at idle to 1500rpm the car is pretty mellow driving through the neighborhood. Screams at WOT. I also run an h pipe, I don't think that will have much of an effect on sound volume but if you don't have it and are already doing exhaust work I would add that or an X.

Dynomax super turbos are very quiet, maybe too quiet. My car has 600hp and at idle to 1500rpm the car is pretty mellow driving through the neighborhood. Screams at WOT. I also run an h pipe, I don't think that will have much of an effect on sound volume but if you don't have it and re already doing exhaust work I would add that or an X.

Dynomax super turbos are very quiet, maybe too quiet. My car has 600hp and at idle to 1500rpm the car is pretty mellow driving through the neighborhood. Screams at WOT. I also run an h pipe, I don't think that will have much of an effect on sound volume but if you don't have it and are already doing exhaust work I would add that or an X.

Maybe try some HEMI mufflers!

I called Accurate Exhaust and had a discussion about the Hemi mufflers. The Hemi's had a different system then the 383s and 440s I'm told which included a crossover and resonators. I think (think) that the mufflers were more free flowing.