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Greetings and Happy New Year.

I am working on a modified '54 3100 with a Camaro stub and a 350 V8. I have scrapped out the entire exhaust except the headers. I am leaning towards dual Flowmaster 50 series Delta Flow mufflers. No cross pipe. I want a nice resonant rumble , that gurgle-y idle sound , but not excessive noise , rapping when decelerating , and certainly NO trombone. I want folks to hear an unmistakable hot rod sound without being a public nuisance.

I am pretty new to all this. Someone please chime in and tell me if I am barking up the right tree.
The mufflers will have about 4 1/2 ft. of pipe downstream from them , straight out the rear.
I think that the inlet will be 2 1/2" ; will have to double check.
Would it benefit the rumble if I were to expand to 3" aft of the mufflers?

Exhaust input welcomed on a cold winter day ,

Waveski.

After listening to an obnoxious rumble from the exhaust on my Ram 1500 for thousands of miles, I paid a few bucks to get a real muffler installed. Some former owner thought it was cool to make noise. Now I can do things like listen to the radio, or just be more aware of the tinnitus I have to tolerate 24/7. If you feel like you just have to annoy the public at large with your exhaust system, start a savings account to pay for the hearing aids you're going to need pretty soon!
Jerry

Hot Rod Lincoln -

Did you read my post?
Do you know anything about Flowmaster series 50? I believe that the product I referenced IS a real muffler.

" If you feel like you just have to annoy the public at large..."
That is clearly NOT my intention.

Sheesh.

Flowmaster has built a well-deserved reputation of walking the razor's edge of illegal, where exhaust noise is concerned. Not everyone agrees that everybody for a block or so in all directions wants to hear "an unmistakable hot rod sound" (your words, not mine). Some of us just think that's being rude.
Jerry

This is the HiPo Forum. Modifications are welcomed here. Those who do not agree with modifications consider our other forums. Anyone doing modifications to their truck should feel welcome here and not have to endure lectures on why their projects are not proper. Of course if the proposed modifications are unsafe or illegal by all means jump in and let us know otherwise keep your opinions to yourselves. Hotrods are cool, period.

Thank you.

I believe that the criteria I outlined in my o.p. were within the bounds of reasonable.

I appreciate your asserting yourself as moderator in this thread - which ,btw, references the Flowmaster 50 Delta Flow which is advertised as having a “moderate “ sound.

(I’ve always felt that a good pun lightens up a situation...)

Addendum:
It is possible that Mr. Lincoln is not entirely familiar with the Flowmaster line of mufflers. They range from completely stock to race track , with a wide range in between. The selection I am considering is in the middle of that range , actually on the quieter side of mid-range.

Flowmaster has an excellent website with sound test videos.

Flowmaster is known for a quality product. It is going to cost you some $ to get the answers to your questions. Put them on with clamps first. You can experiment with different lengths of pipe and using adapters can determine if you want bigger pipes. Your project sounds like it will be a blast to drive. HRL is very familiar with performance builds but he does have a propensity to get under your skin. He really is a good guy at heart but you have to gnaw your way through a lot of gristle to get to it. Good luck.

It's your project, but my 2¢:
Every Flowmaster street car I've heard is louder than I like inside the car cruising, and louder than the owner thought it would be when he ordered them.
As was said, clamp them on and try out different lengths, and different points of hanger isolation before welding.
Have fun!

I once saw a bumper sticker on a hot rod that read, "IT'S NOT TOO LOUD - YOU'RE TOO OLD." Read these replies keeping in mind that the average demographic of this forum is probably about the same age as the trucks themselves (hey, that includes me too!).

The Flowmaster sound is unique and distinctive, and makes a truck more fun to drive. Dudes, if you want quiet, buy a Cadillac.

My 520 hp street toy has 3" dual exhaust, can be heard for miles WOT, yet quiet inside at 80 mph and at idle disturbs no one.
I still have most of hearing at age 75, and not driving a loud car is one reason.

Flowmasters are super cool (or "sick, dude" if you are a millenial) for about 20 minutes, then they become annoying from inside the vehicle.
My 18 cents (adjusted for inflation).

For general information , I am 69 , I don't want to disturb the peace , I DO want to hear my 350 rumble a bit. I just junked a couple of cheap generic mufflers - they did not do the cause justice.
Sick/dude are not in my vocabulary.

The Series 50 delta Flow is said to have minimal interior noise , but I am going off of a product video. Hoping to tap into some first hand experience.
The comments about excessively loud Flowmaster experiences cannot be put in context without having some idea of what was being muffled by what.
A 350 with twin Series 50 3 chamber Delta Flow mufflers is a whole different animal than a 502 big block with single chamber Series 10s.

If a person is interested , the linked site has a simple graphic comparing the various Flowmaster models in order of sound emission.

https://www.holley.com/brands/flowmaster/

From personal experience. I find that Flowmaster Deltas have a high pitch, hollow, "tinny" sound. They also have a ton of in cab resonance. I had a Delta flow on a 02 Ram, I couldn't stand the resonance, so I switched to a long tube glass pack. After I got tired of the noise, I went back to a normal muffler.

I worked at a service shop years ago. I can't tell you how many Flowmasters we cut off, but it was a bunch. We installed Dynonax turbo mufflers in their place, everybody seemed happy with it.

A friend just took a set off of his 74 Camaro and put some normal mufflers on it. Like 52Carl says they were good for about 20 minutes.
You can probably get them cheap.
Fred

I have used mufflers for a mid-1970's Cadillac on several performance engine builds. ONE muffler has the capacity to handle the exhaust volume of a 500 cubic inch engine, and we used two of them on dual exhaust systems. Those mufflers have 2 1/2" inlet and outlet pipes, and they provide a system with virtually zero back pressure without producing obnoxious noises. Those engines were producing 400+ horsepower, from actual dyno runs I did personally, not some sort of bench racing fantasy pipe dreams. Best of both worlds! It's a lot easier (and less expensive) to make noise than it is to make power.
Jerry

From my own personal experience, way way back, I had a '67 Chevelle 283 V8 with "Hush Thrush" mufflers dual exhaust. The car had a great rumble until I installed full length tailpipes to the rear, then it was too quiet for my taste. Eventually, I installed that same engine in a 68 Chevy 1/2 ton pickup (The Green Machine). Headers, Hush Thrush, no tailpipes and it was exactly what I wanted.

I think Martin has the right idea. Make your best guesses and try a few different set ups.

Doing your own research, you may get it right on the first try.

Let us know how you make out.

John

I think a lot of the noise can be reduced by adding a few bends to your system. I have a set of Raptors (similar to Flowmaster) on my 93' 4x4, the exhaust exits in front of the rear wheel on the passenger side. I don't consider it to be loud as I can hear the radio or carry on a conversation... Flowmasters are a great performance muffler, they are load by design compared to a Turbo or Glasspack style.

Growing up my Father had a 70 GMC with 2 1/4 inch corvette mufflers that exited just in front of the rear wheels. It was deep and throaty it had a mellow tone at speed, never seemed overly load or obnoxious.

The comparison to DynoMax has given me something to think about. I've just watched a couple of videos ; there is a tonal difference between it and the Flowmaster. Is it the multiple chambers that produce the higher pitch at some power settings?
Thanks to White Dog for that. Any other alternative recommendations are welcome.

AFAIK the measured decibel level is only part of how the passengers perceive exhaust noise.
High frequency noise is supposedly much more irritating, causing headaches, tiredness, loss of concentration, etc. while low frequency noise at the same pressure level is more tolerable.
From that, I would guess that a manufacturer would go to some trouble to minimize high frequency noise.

In general simple decibel reduction can be done by shapes and baffles (there are literally thousands of patents), but the simplest way to reduce sound without power loss is very large muffler volume, especially cross-sectional area.

As well as frequency, the harmonics with other components (as in the boom box lowriders that you swear are going to loose all their screws) has a fair amount to do with the perceived "noise". Low frequencies carry farther and through things easier than high frequencies.

At this point I have pretty much eliminated Flowmaster. I now understand the relationship between the chambered design and the resultant hollow tone characteristic of the Flowmaster , and it's not what I want. I think that interior drone comes from that metallic sound and associated frequencies.

As I said earlier , I am pretty new to all this... but learning.

Keyed by White Dog I researched Dynomax Super Turbo. That muffler seems to have the rumble I seek ; not excessively loud. Sounded real nice on a Firebird with a 350.

A knowledgeable friend steered me in the direction of Magnaflow , 4x9 oval or 4" round.

It seems that there are lots of good amatuer sound clip videos for Dynomax , but a search for similar sound clips for Magnaflow turns up one corporate promo after another , and they are overproduced and annoying.

Those are the mufflers that I have on my 53, no tailpipes just dump in front of the axle. I'm using 2 1/4" pipe. I think you will be happy with this style of Flows.

I don’t know about the 50’s as much, but my pa in law has the 40’s on his 350 and they drone like a bugger. I am going to try the Borla XS Pro muffler. I’ve read a lot of reviews and they have compared them to the Flowmaster and guys have said, “This is the sound I was dreaming of...”
nice idle, no droning at cruise, good rumble sound, but when romped on they wake up.

The concern for drone at cruise , along with that slight hollow sound , is why I have abandoned Flowmaster quest.

I am presently leaning towards Dynomax Super Turbo. The various sound clips I have watched and heard tell me that the gurgle at idle and rumble at power - without excessive volume - will be delivered by the Dyno.

MiraclePieCo...I'm incensed...I'll have you know that I'm NOT the same age as my '50 3100...2 years younger! LOL

MiraclePieCo ???

Haha, I figured I'd hear some yelps when I threw that rock over the fence ;-)

(Re last post on page 1)

OK , I get it now.

FWIW , I was 3 when my '54 was new.
And I want to hear the rumble. Not blare , but rumble.

I want fellow motorist's to look around at the stop light to see where that unique sound is coming from...I plan on mine more from a mild cam with a little lope to it. It won't take much...cars today including mine barely make more sound than electric vehicles.

Dang right - let everyone within 200 feet know you're there!

Some neighbors might feel this way:

Bought a Flowmaster 50 Delta from 4wheelonline last year, and I can say that this muffler is louder than Magnaflow but not ridiculously loud. I can talk comfortably while cruising on the highway.

The guy who lived about half a block away from our apartment on Okinawa really liked to warm up his small block Chevy engine every morning at around 6:00 AM by revving it up repeatedly for several minutes. His pipes would rattle windows. Several young children in the neighborhood, including my newborn daughter, were not impressed. A few friendly hints, and then some not-so-friendly ones, were ignored. That engine got really quiet when somebody poured a bottle of Karo syrup into the crankcase!
Jerry

Installed the Dynomax Turbo on my 39 with 350, I can now hear without any drone going down road. Quiet at idle, so huge improvement. Had previous noise with drone mufflers. No more as I enjoy new set up. It does have a little rumble going down road.

I am not familiar with the FlowMaster Delta 50. I have a set of FlowMaster MagnaFlow mufflers on my 1962 C10.
It's a 327cid with a mild cam (CompCam XE268H), Factory 4BBL intake, and Factory Ramhorns. Holley Mdl 4165 (650cfm) for the carb. True dual pipes, no crossover and they exit the truck under the rear steps, just in front of the wheels.

Here's a short video a buddy of mine took of my truck on start up and as I drove away in 1st, then 2nd. I was not romping on it, but it has a good rumble to it.

1962 Chevy C10 start up and drive off.

I have been pleased with the sound both under normal conditions and on the freeway.


They sure beat the GlassPacks I had on my old '63 C10 back in the day. :-)

I don't think that the exhaust I am planning to use will elicit that kind of response from any neighbors.
I have pretty much settled on Dynomax Super Turbo. The name sounds racy , but I have viewed and listened to many sound clips and I think the the tone is pleasantly deep and rumbley , but the overall volume is well within reason.
And - no drone.

Here is a sound clip , previously posted -

How to get a "little lope": cross 2 plug wires, and punch a small hole in a vacuum line.
Now, THAT says power!

Well , I come here for knowledge and good advice , and I'm never disappointed.

In the old days we'd pull out the choke cable until it started loping.